Busting Four Myths About Ductless Mini-Splits

Over the past few years we have all observed the U.S. HVAC industry’s fascination with ductless “mini-split” air conditioning systems in the U.S. Recent HVAC trade shows have been crowded with OEM’s promoting this “new” way of providing home comfort. National advertising and media/public relations tactics would make us think it is just a matter of time before we all say goodbye to our central AC systems and get with the rest of the world (i.e. Japan, China and Europe) in the way we keep our homes and businesses cool and comfortable.

The article below was written in 2013. We have updated information for homeowners busting myths about ductless mini split systems, outlining what to consider when choosing a new HVAC system, as well as recommendations on when a ductless system might be right for your space.

The AC & Heating Connect staff has also conducted research on ductless systems and uncovered some facts that might be of interest to contractors and distributors as the industry plans for the future growth of this segment.

Myth #1 – The sales of ductless mini-spit systems continue to grow and will dominate the U.S. market in a few years.

Industry statistics would not support this statement. While the ductless segment has posted impressive growth rates in the U.S. since 2005, the growth rates have been slowing recently and the largest ductless segment (small, single evaporator systems) have not grown at all since 2010. These sales remain stable at about 260,000 units per year, or only about 4% of total unitary AC shipments. Some larger VRF-style commercial systems continue to grow at higher rates, but their numbers in the U.S. remain small at only 28,000 units per year.

Myth #2 – Ductless mini-splits are ideal whole-home HVAC solutions in the U.S.

The current economic facts about ductless simply do not support this claim. The installed costs associated with using mini-splits to cool and heat an average 2,000 square foot home with ductless mini-splits would cost almost three times the cost of simply replacing your central AC system with another ducted system. Even in a home where you had to provide new ductwork for the central system, you could still expect to spend about 50% less on a typical central AC system installation versus the more expensive ductless options.

Myth #3 – Ductless mini-splits are more energy efficient because there are no air leaks in the ductwork.

What people who make this claim fail to mention is that in ducted homes, which have poorly installed and leaking air ducts, the conditioned air is probably leaking out of the ductwork but it is going into the conditioned space somewhere and helping to keep the house cool. In those cases the cooling energy is really not lost to the homeowner. While mini-splits don’t have duct losses, they do have other losses. Instead of distributing conditioned air throughout the home, mini-splits distribute refrigerant. In many cases these refrigerant lines are run outside the conditioned space and in these cases there are thermal losses associated with energy transferring from those lines to the space outside the home. A legitimate energy loss occurs when you are heating or cooling your backyard with mini-split refrigerant lines (see photo below). Duct leaks that leak into the conditioned space are not really losses at all unless they escape to an unconditioned space. The other claim made by mini-split advocates is that they provide energy saving due to “zoning” or shutting off energy use in unoccupied rooms. What they fail to mention is there are other modern methods to zone off rooms besides using ductless methods. There are many ways to achieve zoning.

*Discover the updated status of this myth here.

Myth #4 – Ductless mini-splits provide superior comfort and quality of life.

The problems with ductless cooling are not well understood by many U.S. consumers since they are relatively new to this region. The typical comfort experience with mini-split systems could provide a real challenge for American consumers who are used to central AC systems with good airflow exchange, filtration and humidity control. Cold and hot spots are also common with ductless systems due to the spacing of the indoor units. In addition, there are concerns about US homeowners’ reaction to the aesthetic and architectural impact of having air conditioning systems hanging on several interior walls and having refrigerant lines running to various rooms on the sides of their homes. Before installing a ductless system with multiple evaporating units it might be good to show your customer some photographs of some of your previous mini-split installations so they have proper expectations.

*Discover the updated status of this myth here.

The Bottom Line on Ductless Mini-Split Systems

Ductless mini-split systems are ideal for spot cooling situations in homes and businesses where ductwork is either not available or difficult to install. It is important for contractors to have these systems in their portfolio of HVAC solutions for certain situations and learning where and when to recommend them is essential. Knowing the facts associated with these new systems is also essential to avoiding problems when customers are surprised by the many “myths” about this technology.

The myths in this article have been reevaluated. You can find the updated article here.

What has your experience been with ductless mini-splits? Leave us a comment below!

A typical indoor wall-mounted, evaporating unit – usually one per room are required to minimize hot and cold spots.

A typical U.S. style home is shown here with a retrofit mini-split system. Notice the exterior line sets and condensate drains. Thermal losses could be expected from the vertical, external refrigerant lines and these might cause the system to have trouble keeping up on really hot days. Also, notice that the window-room air conditioners have not yet been removed. A close up photo of the house above, showing the external refrigerant lines and a condensate drain line. Ductless mini-split systems are often used to cool room additions as shown here in the garage area. A large, high rise apartment building is shown, using many mini-split systems – one or more per apartment.A large, urban apartment building is shown, using mini-split systems – one or more per apartment.

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404 thoughts on “Busting Four Myths About Ductless Mini-Splits

  1. We recently bought a 1600 sq ft house (plus basement) in the Boston area, and are doing some renovations before moving in. It currently has no AC. Now that we have some of the walls open we’re considering adding AC, and minisplits seemed initially appealing, except the units all seem very oversized for any of our second floor rooms. We have 3 bedrooms on the second floor, 1 small bathroom and a small master bath.

    We’re estimating something along the lines 2100 btu cooling, 3000 btu heating for the larger bedroom, as an example. We think it would be preferable cost and load-wise to have a single upstairs unit, but are not going to keep all the doors open all the time, esp when sleeping. So presumably air circulation will be an issue if we have only a single unit. So are minisplits a bad solution in this case? We mentioned high velocity AC to our GC but he strongly discouraged that based on cost. However multiple minisplits for the upstairs seem likely to be comparable in cost.

    Are there other solutions we should be considering? No system seems designed for this kind of house. Do we need to resign ourselves to window AC units? Interested in any advice or relevant experience people may have!

  2. I agree with the comments about installation companies in the United States being slow to get on board with this new technology. Sort of like the oil companies being anti clean fuel. It all translates to what makes them the most profit. I hope that more installers will invest the time and money needed to make the switch. I fully intend to ditch my 20 year old system and the dust filled floor vents that go with it in lieu of vastly more efficient, cleaner air that mini splits offer in my 1258 square foot North Georgia mountain home.

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  3. I purchased a Fujitsu Mini-Split heat pump in the fall of 2016. In January of 2018 it ceased working and I have been without it now for 2 1/2 months during the coldest weather of the year and Fujitsu has shown no interest in repairing or replacing the unit. In fact, they have continuously lied to my dealer and myself about how long it would take to repair and now for weeks they have lied about shipping it back to me, saying it is shipped when it has not.

    This in no way reflects on my local dealer, Haynes Heating and Air. Haynes has gone out of their way to help me and is being misled just as I am.

    I should have been more careful. I thought that by doing business with a Japanese company that I was assured of doing business with people who are honorable and ethical. But when my unit broke I discovered that the ‘warranty’ only covers parts, not labor. I wish I had seen that before I bought, It would have frightened me off. Luckily, there has been lots of labor involved here and Haynes is eating all those charges, even though they do not have to do so.

    But Fujitsu has been of zero help, and they will tell Haynes whatever they have to just to get them off the phone. They have had the unit in their shop at Fujitsu for all this time because they could not figure out what to do to fix it in the field. And now they have been saying for three weeks that it is shipping when it isn’t. And they had the nerve to say that they were ‘backed up’ and that is the reason they took so long.

    Customer Service does not allow for this. Honor would demand that they replace the unit if they could not fix it in a reasonable amount of time. You just do not take a customer’s heat source from them in the middle of winter and act like it is unimportant to get it back to them.

    Mini-Splits are great. But choose your manufacturer very carefully. Make certain you do business with honest, honorable people who understand the value of a good reputation. I did not do that. I did business with Fujitsu and have lived to regret it. Don’t repeat my mistake.

    Fujitsu has just reported that my unit has once again ‘shipped’. We shall see. I will update this post with more details when and if the unit arrives and can be made to work. I am not optimistic.

  4. I have a 2400 sq ft ranch house in the SF bay area (Ca). Originally had a 1950’s radiant floor heating that was dismantled. I have two fireplaces and have used both for heat. Now just use the pellet stove in one fireplace and the window air conditioner on the few days of extreme heat in summer. I would love to install a heating system/air conditioning–just don’t know what is the best way to go. I am very tired of going to the store, buying pellets and dragging them into the house. Any advice?

    • We suggest contacting a licensed HVAC contractor in your area to get recommendations for what type of equipment should be installed.

  5. February 25th, Kelowna, Canada. I had a Lennox 3 way split installed in June 2017. 1×12000 btu and 2x 9000 but, the system has never worked properly in the individual rooms. Initially during the summer each room took on the temperature of the lowest setting. During the winter it has been the same. Lennox has just had a convention in the US where they apparently discussed the issues with the 3 way split deficiencies. The repair guy (the installer, not lennox ) just came in and put the sensors above the machine (unsightly). Three days later, today, I figured out I have to turn off the other two machines (heads) so that one will work properly. Do not purchase this Lennox 3 way split. I have been talking to my licensed installer for 8 months. Now am asking that they replace it with another brand, also 3 way.
    I paid Can $ 13 000 (thirteen thousand ) for a headache and no reduction in electricity bills.
    Can anyone recommend the best brand and model for my 3 way split.

    • Mitsubishi is the top of the. Rarely do they have any problems, even after a decade of use. Plus Mitsubishi stands behind their products if there is an any issues. Just find a Mitsubishi dealer and you will get a 12 year full warranty. Two thumbs up.

      • Also! if you use “Cielo Breez” smart air conditioner controller with your Mitsubishi Mini-Split or any brand ductless mini-split. Your energy bills have dropped by 20 – 25%. Well! I used personally. I’m satisfied with Breez’s features and it’s performance.

        • i’m not familiar with the remote you refer too nor sure how it relates to the persons issue at hand. But I’ll say this; not sure why anyone would need any other remote for the Mitsubushi splits – they do everything, have timers, etc…..so not sure how what your selling saves $$$ over the remote that comes with the unit.

  6. I bought one of those new fangled Friedrich Breeze for DIYers to plug and play basically. The tubing was so thick and stiff it was like wrestling an anaconda. Because the tubing was so stiff we were short to the ground and ended up making a two foot high stand for it. We have had it almost 5 yrs in June. The unit was made in Mexico by the original owners of the company and the design was poor. So many complained about how it gave not enough room for the wall unit to sit flush. This causes more sound to emanate into the room. No where did they say to clean the sides or how but after about three years we took a closer look and there was so much crud in the fan barrel. On our own and watching videos we attempted to clean it with a can of cleaner from Home Depot and rinsing with hot water. The smell from it was sooo much better. There had to be mold and pollen and grease from the kitchen etc. We have to clean this about once every six months and it is a messy procedure and each time we do we wonder if we have somehow got water in the electronics by accident. The filters on these ductless units are kind of joke compared to the much more extensive filters you have on a furnace. They are like Fisher Price filters. We have a 12-12K unit for a 1K sf house and it is not optimum. Also it doesn’t do a great job of dehumidifying at all. Our windows condensate and it would be nice to have ducts under them drying them off. I need to use Frigidaire dehumidifiers to deal with all the condensation. We have radiant ceiling heat that the local PUD engineers swore was energy efficient and blah blah blah and they were the ones talking folks into making these houses this way back in the early 1970’s. They lied then and lie today. Friedrich sold out and the new owners dumped the Breeze series. Also there are only like 3 customer tech support people there in winter and maybe 10 in summer. When we bought
    Friedich was the leader in air conditioning unit but when it comes to ductless I think they stink. They will not sell us the parts for it but will refer us to an authorized dealer. Right now we think the thermistor for the room temp is out. It just heats up and doesn’t shut off. The part must be about 20.00 at most. I bet we could replace it but we have to have a guy come out and look at it from about 20 miles away, then order the part and then come back and install it. We are covered for parts for the first five years but the joke is on us since the labor etc will be what 10 times that? I have a call into the guy now but he is one man shop from the sounds of it so not sure when he can make it out. In the meantime I am turning the heat on, then when it gets too hot then switching to fan mode. I am the manual thermistor in the meantime. At night we just run the fan. Honestly I am so sick of the state of affairs with appliances that I am thinking outside the box. This year I bought a fancy new Whirlpool fridge that the stainless steel is rusting in small places all over. I use their cleaner too. They all use the cheaper stainless now and there are endless complaints and nothing is done. They are noisy too! So I am not buying anymore big appliances. Just done. I bought portable induction cooktops I can store in the drawer and only cost me 55.00 rather than spending 1300.00 minimum for an unit that will either scratch easily or god knows what else will go wrong with it. I bought fancy Wolf countertop toaster oven with better stainless steel. I am going portable and cheaper now. I will just keep my old dishwasher since the new energy efficient ones are not better just smaller and they rust! I am done with sites like Houzz that continue to sell us the idea of the ideal house stuff. I am sick of home improvement stores like Home Depot and Lowes that sell us crap appliances and know it. When this ductless goes out I will either get portable heaters and air conditioners or pay for furnace and heat pump. I have done the window air conditioners until I opened the fancy big Kenmore we had and it had mold growing all over inside of it an no way to clean it really! I don’t want to spend a lot of money for crap and will spend less on cheaper crap for now since you get about the same results. My daughter just bought a new house from the biggest builder in our state and it was expensive. They used a furnace and had plastic tubing to the vent ducts. No more sheet metal. It seems furnaces might be a more practical way to go not a lot of cleaning and less noise and the parts are simple and more generic not so many electronics on them to fail. Finding a place for it would be a bit problemic but doable. It seems like health care there is no incentive to really find better answers or solutions it is much more profitable to keep the problems in play so they can keep selling you maintenance approach not real cures. I just don’t think it should be that cost prohibitive to make a better way of heating and cooling that will last and covers all the major pain points these things have. All I can say is build it and we will come running!

    • Deanne, you should check the paper/ craigslist for used appliances. Not a used store, preferably an individual entrepreneur! I found a local man this way. You can get older, well made appliances for way cheaper. The guy I go to also gives a guarantee.

  7. The loss of the refrigerant lines in unconditioned space would be minimum compared to the duct in unconditioned space.
    1. The surface area for heat transfer is much larger on the duct.
    2. The insulation is superior on the refrigerant lines. Just compare the thickness.
    3. Duct leak VS sealed copper line.
    Using ducts in conditioned space as argument is pointless since the refrigerant lines can also be in conditioned space. In face, you can see a lot refrigerant lines run in the wall in new constructions.

    As to the high labor cost, I feel this is totally due the slow adaptation of the HVAC contractors. It is very similar procedure in dealing with the refrigerant lines. Plus in mini split system, there’s no need of connecting to duct work. They charge a premium for mini split simply because they haven’t done this, and not willing to try a new system.

    • As a Certified, Mitsubishi Diamond dealer, I can categorically state that mini-splits systems CAN be far superior to ducted systems when proper heat load calculations are done to confirm the mini-split will handle the latent heat load, i.e., humidity and the sensible heat load of a given area; when they are installed using nitrogen brazed joints; and when the electrical grid they are connected to provides clean , i.e., no over current-under current, brown-down, or d/c contaminated flows, and stable voltages.

      Also, new mini-split systems allow for a combination of ducted air flows, ceiling mounted cassette installations that have 4 directional as well as lateral, sweeping air flows that are totally superior to conventional, ducted systems.

      Installation of Mini-split systems must be performed by certified, educated, installers that stricthly adhere to manufacturer required parameters for nitrogen brazing of line-sets ; pressure testing of the new line sets after brazing ; and pulling the mandatory 300-500 micron vacuums. Furthermore, mini splits require voltage-power sources that are provide clean (i.e., noise D/C filtered current & voltage flows), consistent voltages. And the condensate lines must be properly sized, insulated, and routed to dispose of the large amounts of condensate these units can generate, as they do here in New Orleans. Here in New Orleans, we have the highest mean humidity of 74.2%. Mitsubishi Mini-splits have a built in, dehumidification mode that works excellently. Also, they systems require diligent maintenance to keep their static electric air filters and coils clean.

      We have sold /serviced literally every mini-split of major manufacturers and found Mitsubishi to be the best. Mini-split technology is light years ahead of old split systems… so much so that ALL the major manufacturers of standard ducted systems are now offering D/C full variable speed condensers and ECM-Varispeed blowers… All of which are based upon mini-split technologies.

      If you had / have problems with a mini-split it is probably because: 1) it was installed by someone that did NOT use nitrogen brazing, 2) they did not pull a proper 300-500 micron vacuum 3) the unit is not cleaned twice a year 4) or you used a company other than Mitsubishi which is the industry leader.

      For questions please email or call us at 504 444-2233 for more information

  8. Renting 1200 sf on a bay. Owner installed two mini split units to lower heating cost but my electric bill jumped from $77 to $133 from Oct to Nov. The unit in the living room is set for 70 and the actual temp is 64-65. Does that seem right? Owner has had installers back twice & they’re not happy with the complaints so I’m not convinced they can or will fix this if there really is a problem with the system.

    • Replying with update to my own post:
      My electric bill continued to rise to $176 and the ambient temperature continued to fall to as low as 59, with no change to the mini-split setting at 70 degrees.
      On December 31, I turned off the mini-split and began using only the Monitor-style kerosene heaters in my apartment. I keep the living room and my bedroom at 64 and my spare room at 56. These are comfortable temps for me and my January electric bill is $63.
      I hope the mini-split proves useful for A/C in the summer, but I have no intention of turning it on for heating. For me, these units either are defective anomalies or they are rip-offs.

      • IDK; i had 5 minisplits installed june 2017. I have used a couple of them for additional heats sources in some of my rooms; not all but some more than others – like the TV room. I checked and my Nov vs Dec 2017 electric bills only went up roughly 73 KW. Based on my calculations it was only $3.00 – $4.00 so I’m fine with that.

        You mentioned the setting and the room not being the same temp. When I pulled the trigger to go with these I was wondering how that worked and I had found (and it made sense) that there was no real expectation that the room would be the temperature I had the remote set for. The remote is not a thermostat; it’s my understanding the unit on the wall has the thermostat. So it probably doesn’t make great sense since heat rises BUT I make sure the heat is moving where I want it – floor, circulating, etc……….and have not had a problem.

        What I did notice here is when it’s really cold outside (Cleveland, OH weather) the unit will make some fairly loud noise – something i wasn’t expecting. I researched it and found its likely a ‘defrost’ mechanism and the units do have high/low operating efficiency parameters so I wasn’t alarmed. And when it’s ‘typical’ cold weather they don’t make but hardly any noise.

        Thing is with these units (which many have said) they are newer in the states. That said, you can find a great installer (as I did) but they don’t have a ton of answers for you regarding how it operates, etc………….they will rely, in my case, on Mitsubishi for the detailed operating answers.

        So, while I can’t say why your bill has hopped up as much as I did; I’ve not had the same experience – yet maybe.

  9. We have a 1921 raised Craftsmen 3/2 (over a full daylight basement) in NE Florida. A crazy package unit was installed 30+ years ago and has finally died. Yay! Never really worked and super high electricity bills. I detest the ductwork in my unconditioned attic. And I have a basement. Footprint is 1650 sf. We have and use the original whole house fan to exchange warmed or cooled air whenever appropriate. Love that!
    We feel we see a clear way to add ductless mini splits without hacking up our house in an unsightly way. We should also be able to run line sets and drains through the basement ceiling joists to minimize the external line set runs. And we have plenty of choices to locate the compressor.
    Our problem is, EVERY technician who come to talk new system/duct design, can only see doing a ducted system in my unconditioned attic. Even ducted mini splits they want to put in my attic and cut 20 X 20 returns in my coffered ceilings! Yikes. And, um no.
    I wonder if I am just way off with the equipment limitations or just not finding a creative installer. When I mentioned to the last Tech that we would rather cut a return and vents in the floor vs. the ceiling, and place the ducted mini split in the semi conditioned basement, he said he would refuse because we have hardwood floors. I asked about floor/wall mount type, and he squashed the discussion saying they were crazy expensive.
    This is so hard to find a right fit. Where’s the dating style app where we can be matched up with a seemingly bets fit.
    Thanks for listening.

    • I installed a three zone pioneer mini split and i could not be happier with the unite. I went with wall mount Units. Old central air systems are just to inefficient just look at there seer ratings.

  10. We had the Mitsubishi split system. As far as the looks on the exteriorthat was handled by using the cover up system. Not only did it cover the lines and condensate lines, it also added additional coverage and snow additional air barrier to prevent heat or cooling losses . The structure was vinyl , easily painted to match the exterior color of the home.
    Now, as to the heating and cooling, there were differences. Partof our home is shaded, the back half is south facing and unshaded. The front section was ALWAYS either hotter or colder than the southern facing back half. The mini split system allowed us to keep each section at a desired temp. In those areas that were not being utilized we could either cut off or set the temps to keep their se rooms from being cooled or heated, that alone caused a decrease in our heating and cooling bills. Using the ductless system has lowered our energy cost quite a bit. Our original system prior to hurricaine Katrina was a seer 18 central unit. With the ductless system our energy bills have dropped by 20% and the cost for a 4 zone plus a single zone wound up costing 25% more than replacing the central unit and new duct work. Another plus is the fact that the compressor units were lighter and able to be placed above the foundation easily which prevented further flood damage with other storms. Many neighbors have had to replace their out side units due to the salt water submersion of the units and their duct work ( those with the duct work under their homes ) either cleaned and rewrapped with insulation or replaced.) so not all of the ” facts ” that were used to rebut the myths were accurate. With the multizone systems , using the exterior covering for the tubing and condensate tubing, you can also add additional insulation to also combat heat or cooling loss. Secondly using a heat pump allows you to utilize the heat or cold difference in other rooms to off set temp differences in other rooms as well.

  11. I have a small cape cod house, a little under 1300 square feet. Our HVAC system is on its last legs. Our windows are too narrow for any window air conditioner to supplement for upstairs, so right now we use a couple portable units that are bulky awkward and horrible.

    I have been told that a really large new HVAC would do the whole house, but the problem is that if I want my upstairs at 70 in the summer, we will have to have it at 50 or lower downstairs. Reverse that in the winter for heat. If I want to set my upstairs at 60, the downstairs will be 80.

    Right now we’re exploring options. It was suggested a new HVAC and a split ductless for upstairs. But that sounds like it’s going to be very expensive.

    Any thoughts, suggestions, ideas on costs? (Vague ballparks are fine) Any help to guide us through the process would be helpful. But we have to do something soon. The HVAC is on its last legs.

    • hola Cindy,
      Before moving to Mexico, we had a large older home in the
      South with two ducted A/C units. One for upstairs and of course
      the other for downstairs. The ceilings both up and down were 12′
      with 10 feet’ windows and doors. This old house leaked like a sieve.
      No matter what I had the two units set at, we couldn’t sleep upstairs because
      of the heat, until I replaced the light fixture at the top of the stairs with a ceiling fan. Amazing? You bet, but it changed the temperature to 72*. I don’t know if this will work for you but it did for us. Also we had 6 ceiling
      fans throughout the house. With A/C and the fans we were very comfortable
      even in 105* with 90% humidity. Good luck to you and your house decisions.

  12. Would love some advice! We are building a three-story 3,200sqft home in Rhode Island and are considering using ductless mini-splits for all heating and cooling. Very new to ductless but it’s been recommended by friends that we consider it due to efficiency and ease of maintenance.

    My questions are:
    (1) Each room requires a separate head but what about bathrooms? Are separate heads required?
    (2) What can I expect to pay for heating the home?
    (3) Is it possible to combine/control multiple heads on a single thermostat so that we don’t have to run around the house and turn them all on/off individually?
    (4) We have been told that Mitsubishi makes the best systems. Is this correct?
    (5) We will have natural gas to the home as well. Does it make sense to also have a zoned baseboard hotwater system for heat (for cost savings) in addition to the ductless units for A/C (and supplemental heat)

    Thank you in advance for any help!!!

    • Before I give thoughts/opinions, please know I’m just a homeowner who just had Mitsubishi mini splits installed in my 100 year old home in June 2017.
      – Bathrooms – I say either yes, you need something or……..assuming the bathroom door is open most of the time the cool air will make it’s way in there. For example; I have an ensuite in the master bedroom and the ‘head’ is in the bedroom, not the bathroom. It’s not as ‘chilly’ in the bathroom but very comfortable. My guest bath…..same thing……..it’s off a hallway and guest bedroom and while it doesn’t have it’s own ‘head’ its fine. Same goes for power room on first floor. Now if someone is going to spend hours in there with the door closed – maybe another story. I’ve had zero issues. (placement of the units is important as well and why you need a good contractor.)
      – Heating – I can’t respond, I’ve not had to use them for heat yet
      – Single thermostat to control all – so it’s my understanding that with mini splits that option doesn’t exist. At least it doesn’t with the Mitsubishi mini splits. Funny you mention running around to turn them on/off. Shortly after I had them installed i found myself doing that ‘just to see’ how cool one or two units would keep the living space. Then i thought ‘i’m gonna leave everything run to see what it does to my electric bill.’ As a point of reference, my electric bill running 5 ‘heads’ from two out door ‘compressors’ was maybe only $45 more in 2017 for the same period as it was in 2016. (I used window unit ac prior to my install). So, unless your closing a door to a bedroom or something that isn’t being used you might just wanna let them run to see what your literal and figurative comfort level is. But……….the whole ‘zoning’ thing was one of the selling points of the mini splits for me. That said; there is no single thermostat. Otherwise, you couldn’t control the climate of each living space
      – Mitsubishi the best – I hope so since it’s what I spent $22 grand having installed. But time will tell. Sounds like you are finding out it’s hard to find tons of info on this technology. That was my dilemma as well and why when i found this ‘blog’ is started documenting my experience. To try and help others who were in the same boat as me. The warranty is great through btw.
      – Should you install zoned baseboard heat as back up? I can’t directly answer this because my house had hot water heat throughout so I’m covered. I plan on using the Mitsubishis as supplemental heat (if needed and probably won’t need) as your thinking of using hot water as supplemental.

      Gosh………exciting time for you. Hope this answers some of your questions. Tough stuff………..the concept is relatively new in the U.S. and not tons of info. But i’ll say this ‘from a cooling perspective, I’ve lived through my first complete summer with ‘central air’ and i’m in love.

  13. Hello Frank,

    My home is stucco flat roof home that does not have existing ductwork and no attic space. Have been talking with a few HVAC companies about installing a heating and cooling unit. One company recommends setting combo unit on the roof and putting ductwork in hallway. The second company recommends putting unit and ductwork on the roof. Third company recommends installing a mini split system. Appreciate your advice. Than you, Joanna.

    • We have a mitsubishi on our flat roof home in the Northwest (Washington State). We couldn’t be happier no having ductwork and having heat and air conditioning from one unit. Our electric bill in only $14 per month but it is just three of us in a 3,800 sq ft home. We put cadets in each guest bedroom, spare bathrooms, and office on their own thermostats which are rarely used. We have two Mitsubishi units in our large common area (living, dining, hall) and one in a large master bedroom. Cooling is seldom needed because we are close to Puget Sound. We have a new well-insulated house with LED lighting to reduce electricity costs. It is by far the least electrical useage we have had on any home.

      • Thank you John for your feedback. What do you know about placement of the cadets on the interior walls? Also are the lines running on the exterior of your home unattractive? Thanks.

        • Hi Joanna,

          Since we had new construction we put the cadets just inside the doors with thermostats and light switch above, very efficient.

          The lines on outside from heatpump go into the wall so very little shows on the outside. Not sure how a retrofit would work. However all of this is on the utility side with gas meter, electric meter so one expects to see (stuff).

      • John, is the $14/month electric bill you mentioned in you comment for heating and cooling your entire home? That seems very low. Can you estimate how much electricity
        (kwh)you use on average in the winter? We are building a two-family home in the Northeast and are considering installing ductless mini-splits for the entire HVAC system or doing a combo of forced hot water radiant baseboard (natural gas) with ductless mini-splits for A/C. Also, can you tell me if you think the cadets for the bathrooms are required or did you install them just for extra heating?

  14. my daughter lives in the Keys and her home was damaged by Irma…they are researching and wanting to install ductless units..home is about 900 sq ft.. total gut and rebuild..they will have open living and kitchen with 2 bedrooms and 2 bath. after exposing the wood beams in ceiling they decided to go ductless .cinder block exterior.. any suggestions? thank you

  15. We have central AC but the unit is too small and there is no room for a bigger one. The master is 10-20 hotter then the rest of the house. We are trying to decide if we should do a mini split or do an in the wall AC unit. I can’t find anything that speaks plainly about the cost to run either or. We live in TX and it’s hot most of the time. It just seems crazy to spend 2,000+ on cooling a 400sq space but if we would spend that much in electricity with a wall unit then it makes sense.

    • Hi Lisa, Here are a few answers to your questions. The efficiency or energy usage is usually designated by a “SEER” rating (Seasonal Energy Efficiency Ratio) which should be shown on a label on the outside of the unit. The higher the SEER, the better the efficiency and the less energy you will be using for given capacity setting.

      The room that is warm is probably at the end of ductwork and further away from your indoor cooling unit (evap coil and air handler). By the time the conditioned air gets to that room it may have already been warmed up and lost its cooling capacity. You might look at the duct line that is leading to that room to inspect for air leaks or you might try adding some insulation to preserve the cooling capacity. You can also look at all the other vents in the house that are closer to that unit and maybe close them a bit to direct more cool air to the room that is not getting enough cool air.

      If none of that works and you are sure your system is running properly (i.e. it is cooling the other rooms well, etc) then it makes sense to add a small system to that room to keep it cool. The lowest cost and easiest to install would be a window AC unit. This might address your problem but you would have to give up your window to do it. These are not usually very energy efficient but they are small enough that they do not use much energy anyway and might meet your needs.

      Through the wall units are a lot like window units except you don’t give up the window – but you do have to cut a hole in your wall. You might still have issues with noise like you would with a window unit since you have the whole unit right next to you instead of separated like your central system or a mini-split.

      Mini-splits are available with very high SEER efficiencies and have many benefits – outdoor unit is separate so it can be very quiet. They usually feature variable speed capability so this might address any humidity or airflow issues.

      if your central system is pretty old (over 14-16 years) you might consider just replacing it and adding some duct work to the room that is getting warm. If it is newer than that then adding a smaller unit to that space might work for you. Hope this helps.

  16. Planning to build 950 sf cabin – 2bdrm/2bth, 12×24 equipment basement with joist floor above, rest of floor slab-on-grade with in-floor heating. This is in Central Minnesota. Due to lake-shore building restrictions, we are stuck with current footprint. We will raze and rebuild from scratch, using footings buried 5′ deep. Roof is very low pitch – 2:12 is all we can have. Thought was to use mini-split with ceiling cassettes – one in kitchen-living room area, one small one in a 10×10 bedroom, and one in larger bedroom with short hidden ducts to the 2 small adjacent bathrooms. With heat pump outside, plan is to run line set from unit into 2×6 wall and up to attic – from there run to the 3 cassettes. Attic will be conditioned space, as roof will be insulated – known as “hot roof” in the area. Thinking a 12k-btu for the main, a 6k-btu for small bedroom, maybe 8k-btu for master bedroom with supplemental in-attic ducts to the 2 bathrooms which are both adjacent to master bedroom.
    Any thoughts??

    • Hi Larry, That should work. If you want to be certain on the capacity you might call a contractor who can check to make sure you have selected the right sizes considering things like level of insulation, shade, windows and doors, etc. Another thought might be to have another heating source for the coldest part of the season as the electric based heat pumps (all of them – central or mini-splits) are not very efficient when the ambient temperature gets below about 15F. This is called a “dual fuel” approach when you get something other than electric based heating for the really cold periods or when electric rates are high etc.

      • I see my picture wasn’t complete. Plan is for in-floor heating, as 2/3 of floor is slab, 1/3 joists over 12×24 “crawl space” that is 7′-high, which will also have in-floor heat in its poured floor. Plan was to use mini-split for A/C and for “transitional heat” for Spring and Fall while heat pump can easily do the job, and using hydronic in-floor heat for real winter. At issue is whether we can make ceiling cassettes work. The smallest cassette is much too large for a single bathroom, and we’re trying to figure a way for one unit to handle 2 small adjacent baths and a bedroom.

  17. Appreciate the original poster allowing all these comments even though they aren’t all flattering. It’s good to hear all the pros and cons we can. Thanks

    • Thanks Red! I wrote the original post back in 2013 just to get some dialogue going. At the time there was a lot of industry buzz about ductless mini-splits taking over the world (or at least every home in the US…) and I just wanted to present both sides of the story as to where this technology makes the most sense.

      I think a lot of people can now at least see all the pros and cons. As long as the visitor posts are not offensive to our readers or are violating our policies about ads, etc we usually leave most comments stand on their own. Thanks for visiting our site!

  18. I am really confused here. I think i found a reputable dealer through our local PUD. I have had multiple quotes. The ductless came in 1K less than a furnace/heatpump combination. I have a 1400sq foot manufactured home. He recommended one 1800 btu for the living room/dining room/kitchen space (all open); 900 but for the master bedroom; and 600 btu for the smaller guest room. This is $7400.00 (with rebates, etc). I have asthma so i thought maybe going ductless would be better as far as cleaner air. He told me that the filters can be washed and re-used. Has anyone heard of this? I am having a hard time with the “paradigm shift”.

    • Do yourself a favor and get the furnace and heat pump setup. I gaurantee if you get a reputable contractor to install it will last a lot longer than a mini split. Also parts will be a lot easier to get when a repair is needed!

    • Suzan: while I’ve only had my mini splits for 2 months I’ve now had them through the heat of the Summer. While I don’t have allergies, etc….one (of many) reasons I sold myself on mini splits was the ductless feature. YES! Was a huge paradigm shift for me as well. I have a 100 year old home and architecturally speaking, didn’t want to detract from the house. I’m finicky as all get out and they don’t bother me. That was one paradigm shift.

      I did have them quote my 2nd floor fully ducted and it was mildly more expensive. I kept reading and reading and reading and decided to go with ductless. They were able to hide all but one ‘run’ outside so no eye sores there. As I mentioned, the interior – doesn’t bother me at all like I thought it might.

      Instead, what I have is 5 zones in my 2,700 square foot house that I can cool (or heat) specific to each rooms demands. A south western facing room on the 2nd floor needs set differently than a northeastern facing room on the first floor. I can adjust accordingly in all five zones.

      The thoughts of looking inside ductwork after even a year of use sort of grossed me out. Not to mention 2 yrs, 3 yrs down the road. Fact of matter is how many people do you know with ducted systems that have them cleaned? Then being the skeptic that I am, are they really clean? Each of the Mitsubishi ductless units I have has three filters. I don’t remember exactly what each does but there is a larger one you remove, rinse, let dry and replace. Then there’s two smaller filters that get replaced roughly annually.

      I’m still new to the whole mini split idea as well but I did it and granted it’s only been two months but I’m not sorry.

      (I had started documenting my thoughts and experience on this site because I couldn’t find a ton of information. I wanted to help others contemplating as I did. And I couldn’t believe the original authors article. It was so slanted against)

      • Thank you, Eric!! This article had me a tad worried but now, I’m not. We are scheduled to have one minisplit unit installed this month in our den. I think we’ve made the right choice.

    • Ductless mini-splits are definitely not the best option in all situations. For a normal suburban house say four bedroom two bath, 2200sq ft I would definitely get central heat & air. But if your living situation is different, especially smaller or open floor plan they can be great and yes super efficient. I live in a small one bedroom house with pretty open floor plan about 750 to 800 sq ft and have only one mitsubishi mini-split and I like it cold. Yesterday it was 108 degrees and my 10 year old unit was easily chilling my place to 61 degrees and wasn’t even turned up half way. The thing is amazing. Costs about 25 bucks a month in electricity. You must maintain it correctly which can be a little difficult if done right but also cheap no new parts are ever needed and filters are reusable. The entire cost of maintenance is just cleaning supplies, coil cleaner mostly and the it. I’m very happy with my Mitsubishi.

  19. I am a hvac contractor and I installed 2 multi head Fujitsu systems on a 3400 sqft spray foamed house in arkansas and so far there electric bill this summer has been $100 a month.

  20. We installed two mitsubishi mr slim units in our barndominium here in south texas in 2015. It is a small barndominium and it is insulated very well but these things are still amazing. I didn’t run them that much in the winter for heat but in the summers i keep them at 64-65 inside and on dehumidify mode, my wife swears we can hang meat in here. 😉
    I am starting the dream house in 3 months and contemplating using mini splits we like them so much…

    also, if you want to get the most out of the cooling/dehumidify mode you should run it on whisper mode. This causes the air to pass over the coil longer which is key to dehumidifying.

    • I am planning to build a small 1150 square foot barndominium soon. I want to do the mini split system but I’m told it’s just too expensive. A builder of barndominiums tell me this and then I called a AC Service close by and they said it was over $5,000 a piece per unit. Then I noticed I can buy at Home Depot for around 1700 and anyone with some electrical and or Plumbing Service can actually install. I’m so confused. But this is what I want and I wish I could find someone here in South Texas to do it. Thank you for your input.

      • Yes you can find mini splits at Home Depot. You can find a or ofmthings at Home Depot if you trust their contractors. That will be your call.

        I had a “diamond” hvac installer (Mitsubishi talk) do the work for me nuts to bolts. Total of 5 areas (units) and cost about $21k and change. This did not include the upgrade I had to make to my electric panel). So you can do,the math.

        Here’s why I’d only work with a qualified installer:
        1. They sized each unit appropriately for the room size, space and location of each room. They take things into consideration like first or second level, room size, exposire to weather, etc…
        2. They’ve done this before. I have an old home and did not want someone drilling holes in my house that didn’t know what the are doing. I also wanted someone to use their head and hide as much of the our door lines as possible.
        3. I wanted someone who could give an honest opinion for the location of each unit.
        4. Cost is important. I had quote from two diamond installers. I chose the more expensive because I worked with them before and they seemed more ‘into’ my concerns and questions. They didn’t pressure anything.
        5. They have a ‘hotline’ right in to Mitsubishi
        6. They’ve been responsive to all my questions and follow up
        7. Extended warranty on parts

        There could be many reasons why something cost more or less. These area few that made me feel comfortable making the decision that I did. And these guys gotta pay people. I had a crew of 3-5 people here for a week straight not to mention some follow up.

  21. I am in central PA and always used window units.I Got older and tired of lifting them so I contacted several contractors on mini split installations. Most of them tried to talk me into central air and was quoted 12.000 to install because I needed ducting also. They were really against minisplits. Finally I got a contractor to install two 12k mini units and that was the best move I could have made at 4,600 dollars complete. Going on five years now and absolutely love them. I get them serviced every year and the evaporator squirrel fan is critically important that it gets cleaned annually or performance will go way down so I clean IT myself. I realized the contractor was not cleaning that fan even though I paid for it. You really have to watch these heating and cooling guys, many will take shortcuts and many will mislead you on what you need to install. Its a nasty industry full of shady technicians. DO YOUR HOMEWORK so you can decide if you have an honest contractor.

  22. I have installed pioneer brand in a 1300 sq ft rental house. 1 in living room and 1 in each bedroom. I keep asking tenants about their electric bill, highest bill in the last 2 years was $140. Cost for each unit was around $600. I’m a technical person and my husband is a mechanical person, so we were able to install ourselves. No problems so far. The remotes that came with them are pretty cheap, one year when changing from cool to heat mode, it didn’t want to go to heat. But a quick search and found out to take the batteries out of the remote for a few seconds. Did that and was able to swap to heat mode. They have been a great investment and tenants are very happy. Not nearly as expensive as what’s been mentioned here.

  23. We are researching this now as our current standard AC will cost 2,000 to do a quick fix but is still R22 refrigerant which we were told is won’t be available after the yr 2020 OR pay $8000 to upgrade to a 410 system.. Our unit is 11 yrs old so we will just be replacing with new one way or the other.. House is 1340 sq ft and not open floor plan with 3 bedrooms.. Wanting to hear if the refrigerant used is R22 in these and if any of you have similar sized home and how you like the system etc.. Thanks to any and all answeres

    • These are 410A coolant. Most new units, split or central, are 410. If someone is trying to sell you R22, I’d avoid them.

  24. Eric, I installed an LG 12000 btu (with seer 21.5 and hspf of 11.0 mini-split heatpump) in a 400 sq.ft. cabin/cottage that I had insulated well. It was all I needed to heat the cottage over this past winter. It performed extremely well was super quiet ( never needed sleep mode) and it heated that space for an average cost of 90 per month ( estimated since I used a 150 watt heat lamp in a very well insulated crawl space to insure water pipes etc were protected. I also installed an outlet in the cottage so I could use a garge heater as back up but I never needed it since this past winter was a little warmer than most.
    One thing about heat pumps though that it is important to note. If you oversize the unit so that it short cycles (ie doesn’t run the defrost cycle consistantly) then the performance will suffer… better to go slightly undersized than over sized.
    My experience with LG was so satisfying that I am installing them in my new 1600 sq ft cottage.

    • Thank you for the comment about making sure the defrost cycle runs sufficiently. That is the first time I have heard that and it is important.

  25. I installed a Mitsu mini HP in a problem area of my home last year. Kind of a stranded room, west side. We built 28 years ago, open plan 3 floors. Difficult to get good ducts to that room. Verdict, wow, amazing! I can’t tell you exact power use aside from stated 31 SEER but that thing put out heat ALL winter, and cools beautifully in the summer. So impressed, I am starting a reno of a 1951 Cape Cod shortly. It has 7′ ceilings in bsmt made lower by ductwork. It is complete gut and redo with 2nd floor expansion. I’m trying to figure out how to do whole project without central HVAC, only splits and a few strategic air movers. All new windows and siding so maybe I can put exterior pipes into walls, or build small exterior chases into plan. Any advice appreciated. Fully open mind here…..

  26. We are having two 5 unit systems installed with all the piping and drains inside conveniently placed closets that run down the sides of our chimneys.

    Yes it is more expensive then traditional, but like my father always said “you get what you pay for”
    It’s way more efficient, way better then window units, way less work the. A traditional system
    It gives every room custom temperature control-awesome compared to traditional systems.

    I’m not sure where this guy got his info from, but I completely disagree with it.

  27. You need a new job, perhaps join the ductless mini split industry for a better paying job that is not sad like this one.

  28. I’m having 5 mini splits installed in my home the week of 6/19/2017. One mr slim ducted and zoned for the kitchen and another mini split on the wall on the opposite side of the house. Then one unit each in each of three bedrooms. I have an almost 100 year old home which is about 2700 sq ft.

    This IS NOT inexpensive. First I need to have my electric panel upgraded to 200 amp and then the installation. Total will be around $25K. I’m in Cleveland Ohio and had other estimates and they were on par.

    I did a ton of research and hope it doesn’t fail me because as I said, this isn’t cheap. Only con I personally have for mini split is what most say; the looks. Over time, if they bother me, I will find a way to camoflouge somewhat with shelving, draperies, etc….I’ve vacationed plenty in the caribbean and it’s pretty much what they use. I loved them and didn’t notice them so much on the walls.

    The pros, as I understand them, are: efficiency, zoning, no duct work and germs/bacteria, no surging power on and off, some pretty cool technology (i see), heat option if ever needed, inverter technology to slow or speed dump the fans and more.

    I know I sound like a brainwashed commercial and I am praying I’m making the right choice. I’ve googled, chatted, visited YouTube, etc……which has lead me to my decision to use these mini splits. Thus far, just from my research phase, my only draw back (and it’s substantial) could be how they look.

    Keep your fingers crossed for me.

    • Update to my post dated 6/9/17: (I’m trying to detail my personal experience because I couldn’t find all the info when I was researching)

      Day four of installation. Maybe I’m lucky but the install team is doing a great job. Almost done. They are hiding what they can, the best they can, outside the house by running the line hide under eaves where they can. They are spray painting it to match the dark brown trim color of my Tudor. They’ve listened to me and have taken my suggestions with my ‘always’ caveat of ‘as long as it doesn’t interfere with operation and maintenance’.

      They are ducting the kitchen in the toe kick with a handler on the basement ceiling. This unit will have a conventional thermostat (vs remote) and will tie in with boiler heat and use the mini split as the secondary heat source if ever needed. That was my call since today gas is cheaper than electric). They did an amazing job cutting the return under the radiator in my dining room (perfectly centered and set back as far as it could) and I already ordered an iron grille cover to dress that up a little.

      Was about 90 degrees here yesterday and the unit in master bedroom was connected and ready to go. Granted, I’m coming from window units, but these things are so quiet I had to put my hand in front of it to know it was running. At higher fan speeds you hear a bit more but it was still quiet and imo there’s no reason I’d need to run high fan speed for more than a few minutes. I even put this 15k but unit to the test and slept with bedroom door open and I was comfortable all night.
      As was the master bath this a.m.

      Provided these suckers are as reliable and as energy efficient as I think and they do as good as an install as I think they are my house is going to be extremely comfortable and quiet. Checks I’m happily writing.

      Now I need to master the remote.

      • Eric, do you care to share your selection of mini-split vendor after all of your research? I have just begun to look into mini-split systems for my 450 sqft lake cabin and would appreciate any advice and manufacturer selection info. Thanks!

        • Brian, I went with Mitsubishi. One contractor quoted another manuf (American standard) only after I asked. His first quote was Mitsubishi, and as I stated earlier, I was surprised how expensive this endeavor was when I first started investigating. When other estimate/s came in on par I realized it is what it is.

          Granted, it’s probably the ‘big’ guy who has the marketing $$$ but I felt comfortable since Mitsubishi is the one I could find ‘lots’ of information about.

          From what I researched, and it makes sense, installation is as important as the install so if going with Mitsubishi I think you’d want to look into the Diamond dealers if you choose Mitsubishi. The warranty is 10 (maybe it was 12) years for parts.

          Hope this helps a bit

          • Eric
            We live in Georgia and are looking to heat and cook basement. It’s small…600 to 800 square feet with doors. Any suggestions on what to ask a manufacturer for to cover all rooms? I would der if there’s one unit that can be used on all or most rooms. Thank you

          • Hi Shea

            I’m not a contractor but can share my experience. There are units that can cover the square footage itself but then the question is will one unit be enough to make each room comfortable. Certainly the room the unit is installed in will be comfortable and the cooler air should eventually make it into the other rooms (to some degree) when the doors are open. One of my contractors suggested installing one larger unit in one of my bedrooms and nothing in another. He said ‘on a bad day it should be comfortable enough.’ Another contractor suggested installing two units (each smaller in btus) in each room rather than one and that’s what I did.

            My contractor measured each room and took into consideration where the room is located (1st floor vs 2nd and north, south, etc exposure). He also had some calculation assuming it was 90 outside and I’d wanna run it at 69 degrees. That’s how he sized my units.

            This is why a good contractor will be helpful.

          • Hi Eric,

            My wife and I are ordering tomorrow a 3 ton/3 zone mini-split system. I inquired about the warranty to our local A/C-Heating and Cooling dealer and he said Mitsubishi mini-splits come with a 10 year warranty and add another 2 years to the 10 if it’s installed by a registered Mitsubishi dealer. So 12 years is their warranty. As to how great the warranty is? I’m not sure. He told me in the 30 years he’s been installing Mitsubishi mini-splits he’s only had one service call! The problem was the mother board went out in one of the air-exchangers (the units that hang on the wall) and Mitsubishi sent it to him overnight at NO cost! He swears Mitsubishi is THE best mini-splits you can buy. And a great company that stands behind their products!

  29. nothing made today is made to fix. so you take your chances with quality.but installing minisplits is cheaper than ducted. where he gets 3x more is beyond me. with a/c cooling mode the omnly hot and cold spots are due to elevation levels in a home. cool air is like water and will easily disperse throughout even from 1 location. upstairs should always be blocked at top of stairs to hold the air up. as bfar as looks. look for the backsides of closets or use a partion. easier than ya think. and the duct loss thing were that doesnt lose efficiency is crazy. air lost has to be made up and the high ambient of an attic kills any efficiency you may have thought you had. attic installations and roof top units should be illegal.

    • I completely agree with Greg. The loss due to bad ducts makes the air leak out in the attic which should not be cooled. Also, the closet real estate space lost for Central Air also isn’t considered in this article. Neither is the fact that you can have a “ducted” ductless system that works almost just like central air but still costs less to install.

    • Hi. So I could use one unit for 4 rooms, especially for cooling? InGA, we don’t use much heat anyway…also, have you heard of Alpine mini splits? There Blue Ridge model is only around 500.00. No middleman!

      • there are many minisplits that offer 4-zone applications. keep in mind that the smallest usually is 7-9000 btu/head. that will do a very good sized room. everyone has there own calculations but i use 600 sq ft/12,000 btu. most often you can get by comfortably with 1 head/floor. and i still cant imagine it being o.k. to have leaky duct. and like i said before, duct installed in an unconditioned space is defeating your own purpose. ive had to do it a few times but the kind of people that want it done certainly deserve it.

        • You can’t really use the 600 square foot per ton rule. It might get close then again it might not. The only way to get a true idea is to do a Manual J. For example, I just did a manual J on a SIP panel home in the Kansas City area. It’s 1,300 sf and the manual J called for 9000btu. The house is a super high efficiency home. It just depends on the house.

  30. I just want to add that every situation is different and sometimes traditional Central IS the better and cheaper option. We have a half ranch house, there is just a master bedroom and bath on the second floor but just the front half of the house. So from the front we look like we have 2 full stories but the back half has a tremendous attic space. Out main living area is huge and open and we’d need a crazy assortment of unites if we went ductless. It would actually have been MORE expensive for us but we also did one zone for the whole house, putting vents in the knee walls upstairs. Our total cost was 9200. Would have been closer to 15000 for 2 central zones (and I think our attic on the second floor is too small for vents and equipment though one guy said they could do it) and ductless would have been at least 15,000. But given our layout nine of the 4 guys we called even bothered to quote it . One corner of my dining room isn’t easily accessible as there are bedrooms on one side and a den extension on the other side, that whole corner would have been a problem. I know people who are thrilled with ductless, it’s a great solution. But not always the best. Where I am central adds value, ductless does too but not nearly as much.

  31. This is hands down one of the most ridiculous articles I’ve read regarding ductless. We have Mitsubishi ductless in our home, and it’s our main source of heat. It’s the most comfortable, quiet and efficient system in the market. We had Carrier’s highest efficient furnace and air conditioner for years, and our electric bills with Mitsubishi ductless are about 25% less, and we’re so much more comfortable.
    We looked at other brands of ductless and even the one’s you could buy online. However, consumers have to be smart! Find a qualified, certified, trained HVAC contractor that has a history of installing ductless, and you WILL NOT have any issues.
    For the record, Myth #’s 2,3,4 are all garbage. It’s one man’s opinion who probably does not have ductless installed in his own home. As for Myth #1, give it time, there’s a reason so many ductless company’s are popping up all over the US.

  32. We have an 1900 as foot house with lots of open space and a master suite on the second floor. We had a few people, not in the industry, tell us ductless was the future. We had a few contractors come in and all three agreed that given our layout and the available huge attic space (house used to be a ranch, the master suite is only the front half of the house so the back has the original roofline) traditional central would be significantly cheaper for us. We’d need too many of the ductless units, inside and out (even if we had those that could control 4 indoor units) and one guy said the way the tech moves and repairs happen you can have issues with a part replacement on all indoor units or a few, vs just one part on your central unit. For homes where installing central ducts would be difficult or excessively expensive ductless is the way to go. As is true for the many, many cape cod style homes in my area. We decided cooking the whole house with one unit makes most sense even if we don’t use the second floor during the day. The energy loss would be lower than cool air running uostsors all the time and there’s no nice way to block it off. I like that the air in a central system is filtered. Great for allergies or odors if you have pets. The one thing I always envied when in houses wuth central was the nice, cool, bathrooms. You wouldn’t put a ductless in a bathroom usually and not eith window/wall units, which I grew up with. Not having a wall of hot air hit you in the bathroom was always my favorite feature! I think each home needs to be evaluated case by case. Friends of mine who are installing ductless still think I’m wrong. They also argue my taxes will go up only with central. Yeah, because it also increases your value! Ductless is great, don’t get me wrong, but it’s still not central. It’s popular in Asia and Europe because of the age of the buildings. Things here aren’t quite as old.

    • I’ve did a lot of web search comparison between all the models and the Mitsubishi brand is what I’m considering. Keep in mind, it all depends on where you live, how well your house is insulated, do you want it for AC or do you need it for heating as well, warranty, support, cost, and cost of insulation if you are not doing it yourself.

    • We just had a 12,000 btu installed in a bedroom. The room only had one air vent and a sun room off of the bedroom. This unit is a heater as well. It is unbelievably quiet. Additionally, it is big but this type of unit was really our only option. Thus far very happy.

    • Fujitsu systems have the highest efficiency rating and best warranty on the market. Mitsubishi has a similar warranty but is less efficient and a bit more costly due to Thier advertising directly to consumers. But both are top of the line systems.

    • Fujitsu systems have the highest efficiency rating and best warranty on the market. Mitsubishi has a similar warranty but is less efficient and a bit more costly due to Thier advertising directly to consumers. But both are top of the line systems. You will be satisfied with either.

    • Fujitsu systems have the highest efficiency rating and best warranty on the market. Mitsubishi has a similar warranty but is less efficient and a bit more costly due to Thier advertising directly to consumers. But both are top of the line systems. You will be satisfied with either one.

    • We put a Mitsubishi system in our new home and are very happy. We have the lowest heating and cooling costs ever by a large margin. It is just two of us and we have a combination of three Mitsubishi units, two on main floor and one in master suite. The individual bedrooms and baths have their own thermostat controlled wall heaters which are rarely used. We also have wall heaters in each room of an ADU in the basement. We therefore only heat the areas we use the most and don’t waste energy heating unused spaces. Our home is 3,850 sq ft including at 750 sq ft ADU (rental).

  33. I have a klimaire 36,000 btu 16 seer mini split heat pump tri zone system that only has two indoor air handlers a 9000 and a 12000 I want to add a third 9000 indoor air handler… this system is only three years I am told by klimaire that I have to replace the whole system because they don’t sale just the indoor units is there any other indoor unit that I can use with this system

    • Hi Sandy – It is pretty difficult to add an indoor evap to an existing multi-split as they are designed for a certain capacity and number of indoor units. You might be better off just installing a separate single split. You can ask a few contractors but I would look into that option for sure. Hope this helps. Thanks for visiting our site.

      • Unfortunately you cannot just add to the system if the system is only designed for two zones! You would have to replace the whole system or just install a single zone for the additional space!

        • She clearly wrote that she has a three zone 36,000 btu system currently running two zones, one 9,000 and one 12,000. What’s happening to reading comprehension these days.

        • She clearly wrote she has a three zone, 36,000 BTU system currently running only two zones drawing 21,000 BTU total. What’s happening to reading comprehension these days?

          • You are correct and I missed that “tri zone” comment. I guess they are just not willing to sell a separate indoor unit. It is surprising to me that all three were not installed initially. Thanks for commenting.

  34. The article was written by someone who makes statements which are FALSE.

    Duct work is run out side of the condition space in LOTS OF AREAS of the country.

    there is really no comparison for mini splits vs a whole house ac system. If your whole house goes out your not going to convert to mini. Throwing numbers about is a fools errand. Each install must be evaluated separately.

    Seriously, hot and cold spots exist in almost EVERY installation. Not just mini splits

    There are ways of cleaning up the installation of the refrigerant lines. I have sheet metal boxes made and paint to the color of the house.

    • I couldn’t agree more! Each install is different and I’ve seen many attics that have central ac in them, not only is it not a conditioned space but the ac creates more heat in an already hot space. I have swapped out my old single pipe oil steam boiler and now heat my whole house with mini splits and I went from spending almost $3000 a year in oil to about $700 in electricity per winter

  35. There a racket going on against ductless mini-splits. In Asia and many parts of the world, this is the de-facto system, and it is relatively easy to install, and efficient. How can it costs $2000 and more to install a $1000 10kBTU unit, that only takes 3 hours or less to install?! I was even told its $8k to install one. So the AC guy just say it is better to install the clumsy central unit instead …. to cool 1 room / garage.

  36. Hi my is Antonio Almodovar i just started looking at ductless air coniditioners i am looking to my hold house at a good price i have about 18,ooo. sq ft.

  37. Let’s mention ducted hi pressure systems.
    Those seemed to never have had their spotlight time !??????
    I did my own home and I have no visible refrigerant lines or
    huge boxy interior units. Just flush and tiny 2″ holes in my ceiling
    and a soft wherrrr of air. No hot or cold spots.
    My unit even has soft-start or slow cycle of air when not cooling
    to keep things even temp. Also works well if you have a fireplace
    to get the heat around the whole house evenly if desired.
    Zero maintenance in 15 years other than 1 filter periodically.
    No ducts to clean ever because nothing can remain in 50 mph airspeed. No duct leaks… it’s all 1 solid and insulated tube from the unit to the duct and all ducting is wrapped in fiberglass and
    reflective Mylar. I have a 3 floor home and it’s not ideal for this setup but I was able to do it fairly easily.. I am handy though 😉
    UNICO system was my choice… there are others.
    I would think most people researching splits already have heat…
    therefore, like me, I needed just art conditioning.
    I elected to go with UNICO but there are others..
    I carried the cube units ( evap, blower, intake.. etc) to my attic myself and just clicked them together with this suitcase style latches… ran my line set through one of the same accesses as I ran some cooling tubes. Called my air conditioner friend and he
    finished the gas work for $180.00
    I would do it again! Not one regret or unsightly boxes or pipes.

    • Where were you able to purchase the UNICO components from to put in yourself? I’m gutting down to the studs a 2000sqft old home comprised of two additions that makes putting in traditional duct work difficult. I’m going with hydronic heating, but air conditioning is a challenge and at least with the UNICO I can even put in a hydronic heat exchange.

      • Any semi gutted place is a dream for a UNICO.
        Being into heavy handyman, it’s easy to open accounts all over
        at all wholesale places under just a business name and get almost anything at wholesale. I don’t abuse it or make myself a hack-. I just purchase it and do what I can in a professional manor and leave the gas work to the pros… if you can find one that doesn’t call you a scab while he’s finishing your work .
        Too funny…. there techs that will take interest in finishing and overseeing your install and not be pissed that they missed an
        opportunity to rake you…. there are plenty of those unfortunately.

  38. I love my mini split unit. I live in less thang a 1000sq home.
    My problem: my insurance hasdropped me because they don’t consider it a central heating unit. No i am on the look out for insurance that will accept my ductless unit. Any ideas who i can go to?

    • I own Access Insurance in San Antonio. Your current agent does not understand mini splits. The only requirement should be that the heat source is thermostatically controlled. I just installed 3 in my 2500 sq foot house. Let them know it is a mini split heat pump system.

  39. Hilarious… very little knowledge in any of these comments. In Mexico, you can buy Mini-Splits off the shelf. I love how people who are not in the industry say everything is so easy. If it was everyone would do it. They are no different than window units and 10x more complicated to work on and repair. If you have an issue with your standard duct system it’s because you got a low bid, unlicensed moron to install it and didn’t bother to think to keep up maintenance on it just like you will with your mini-crap unit. Don’t bother replying because I have had my larf and am moving on.

    • Good points. I would also suggest that people reading this should check the US regulations for unitary systems including ductless mini-splits, regarding both refrigerant (now R-410A) and the minimum allowable efficiency standards (now 13-14 SEER – depending on the DOE region). There are differences between regs in the US and Mexico. I am not saying these regulations are right or justified. Just sayin the US has different standards and they are enforced – unlike many of the “developing countries” who were not held to the same “standards”. Do your research and talk to a few good contractors. What can that hurt? You might save some $ and avoid a costly mistake. I know where AC Genius is coming from. There are a lot of posts about non-US applications on this site. Most of the visitors to this site are US consumers. We might get into writing about international applications at some point but we are still dealing with US issues at this point. Thanks for visiting and commenting. I am just trying to clarify some of your points for our readers.

  40. We put in ductless in our 1980s New Hampshire home 5 years ago and love it. But obviously we don’t have the really hot conditions of the southern states. Now we have plans to build a rustic cabin in Texas. We would like to use ductless again, but the climate is so different. Would we be foolish to do so?

    • Hi Naomi – since you already have experience with ductless systems you might just want to review some of the pros and cons described on this and other article threads on the site before making your decision. Reasons for going with ductless include: zoning for control and energy savings, ease of retrofitting into a home without ductwork and possibly lowering your costs to install and operate. Reasons for not using ductless include concerns about air-flow and filtration throughout the whole home, dehumidification on humid days and heat pump heating on very cold days and nights. One thing you might consider is a hybrid approach that features a basic, small central system (heating and cooling or heat pump) with several mini-splits in the areas you want to zone off or control separately.

      Here is a link to a homeowner survey which might provide other insights.


  41. I posted this “ductless myths” article over three years ago. Since then, over 400,000 pages have been viewed by people wanting to learn more about this topic along with wanting to see the various opinions about ductless mini-splits shown in the almost 300 responses that have been posted since then. Some of these posts are very pro-ductless and some are less than favorable toward the technology. I would encourage people who are interested in this topic to read comments from both sides of this debate and then form their own opinion about whether going ductless is right for their situation. And we always recommend that you talk to a few different contractors about different system types before deciding which to use.

    I posted a follow up article a few months ago which attempts to summarize conclusions we have drawn from all the various responses to the original article along with a summary of the opinions shared in the various posts. This could help provide some additional insight into this topic and an overview of the 300 posts to the original article.


    We also have posted the objective results of a 2016 homeowner survey of over 700 US consumers who recently purchased ductless systems, why they decided to use ductless technology in their home and what they liked or disliked about them. This should help you understand if your reasons for choosing a ductless system are similar to those who are already using this technology.


    As I have watched this debate play out in the US HVAC marketplace, I continue to believe that ductless mini-split technology makes a lot of sense for many applications – and some more than others. Ductless has proven to be an ideal solution for many applications but like most things in life there are no absolutes and there are often trade-offs which should be considered, studied and understood before investing. On this site, we are attempting to provide a forum for people to hear both sides of these and other debates about HVAC technology in a fair and open manner. I hope our visitors find that some of this information is useful.

    • I like your review and subsequent comments. I’m personally looking at a mini-split system right now for cooling and supplemental heating (I’m using whole-house underfloor heating) in my new house build. The design doesn’t really allow for ductwork and the relatively small size (~1000 sq ft) makes me think that ductless is the way to go.

      • H Jerry,

        That should work. Just make sure you get a few different quotes and make sure they get the capacity right for your space and the cooling season load. There are some articles and posts about the trade-offs between single splits and multi-split (multiple indoor unit) ductless systems so you might want to research those before talking to the contractors.

  42. I live in Washington state and got multiple quotes for ductless heat pump and installing duct work and a heat pump and the ductless all came in about $3,000 under the price to add duct work and heat pump. Also all the energy companies give rebates for going completely ductless or natural gas because they say they are more energy efficient. There is no rebate for a normal duct heat pump even though we are upgrading from baseboard heat. I also have people I know that have been in the hvac industry and told me that ductless is the way to go. I read this article first when I first was researching about the ductless systems and ductless is the way I’m going. A lot of this article is not accurate. Just make sure you get your ductless system sized for your house and you will be fine.

  43. What a farce of an article. Clearly worded to steer people away from purchasing these units. The central AC is a beast of inefficiency. Some rooms hot, some cold. Also, the AC technicians try to sell you $7k units everytime something goes wrong with them. Instead of replacing a $150 part you have to hear the $7k sales pitch. It’s BS! I’m ripping my central AC out so it’s for sale if anyone wants it.

  44. I’m an HVAC contractor in the Caribbean. A couple of things were not mentioned here in favor of Ductless. It takes a lot of energy to spin a PSC blower motor to push and pull Air through ducts. I routinely see 40 watts per ton or less on a Ductless for Air distribution using variable speed D.C. motors. Ducted systems will be 3-4 times that. Also, most modern Ductless systems are inverter type variable speed compressor. The system can idle along at 1/3 capacity all day at a super high EER, distributing cool, dehumidified air increasing comfort and saving energy. I lived in a home for a year with 4 Ductless inverter systems. The insulation was non existent but The comfort level was great and our bills were low. Now we live in a house with Ducted splits, 18 SEER, and it’s far from comfortable. Bills are ridiculous. The system comes on and we freeze. It cycles off and we sweat. All day long. On, off, on, off…there’s no comparison. Ductless is here to stay and central Air will become an antique in the next few decades. It’s 80 year old technology and we Americans are the only ones still using it.

    • Where in the carribean are you? I’m looking for an English speaking company that would replace be able to replace my current (leaky) central air conditioner with a multi-split. I’m in Bavaro, Dominican Republic. Right now I have to refill with refrigerant every 6 weeks. which is not cost effective.

  45. 3000sq ft running Gree Crown in Northern MI, running a 36,000,30,000,24,000 7 head units. Love it!! Problems include covering outdoor units to protect from weather. Benefits, electric bills from radiant heat to mini’s 500.00 bills to 200.00 for electric and a warmer house. If my whole system dies in 4 years and has to be replaced, if will have paid for itself. Cost was 10,000 I put it in.

  46. Just thought I’d shed some light on your cost comparison, with central systems bring 50% cheaper. Well I’m in the final phases of a 3,400 sqft custom timber frame build, I assume you got your figures from well…..Not an installer that does this everyday. Cheapest quote I got for central ac here in NC was $22,000. Mitsubishi dustless came in at $16,000. Funny enough the ductless is 20 SEER, and the central system only 15 SEER. Have you ever ran an efficiency calculator on a 5 ton system with with two separate systems 5 SEER apart. Ignorance is bliss.

    Readers, please do your own research on the matter before taking the advice of one guy, one article. Not everything on the internet is truth, talk to a certified professional with a long track record. Such bad information.

    • Thanks for you comments Zach. The cost estimates I used for that article were based on national averages across various regions with no allowance for non-standard construction or other installation challenges. However, as we note many times on this site and in this article, prices can vary from job to job, location to location and from contractor to contractor so we always encourage getting multiple quote until people find a contractor who can install the equipment to meet their needs – and this includes ductless. There are situations and comments posted on this article and others where I have supported the use of ductless systems. I agree with you that for many applications ductless systems will work fine and can provide both operating and first cost advantages. Thanks for pointing this out.

  47. This article is extremely biased. We love our ductless mini split system and it heats most of our house up with just 1 unit. Eventually we want to add one in my office and one in the bedroom for those winter months when it gets a little chilly in San Diego.

  48. Mr. Landwehr,
    When you include one out of four, (that’s 25 percent), unclear or actually false statement in your information it leaves it all ‘suspect’ at best.
    I suggest you consider rewriting or removing you “Myth #3” from your above story. I have NEVER seen nor spoken to anyone, who has seen ducts IN climate controlled space except in warehouse type stores and THAT is obviously Not who you are writing to regarding split (mini) system A/C units. I came to this site looking for ratings to share with potential users, but when I read #3, I knew, I couldn’t rely on the remaining portions. You will probably delete this but at least present your position with accuracy for those who may view it in the future.

    • Hi Dan. Thanks for your comments and opinions. We have had a lot of debate about those issues you raised in your post so thanks for sharing. I guess I was referring to ducts that were on interior wall spaces and not on external walls like the linesets on multi-splits. I hope that helps to clarify the point I was making. In any case thanks for using our site. We do not generally delete posts unless they are violating profanity or endorsement policies so we will leave it up. Maybe others will comment!

  49. Í don’t agree with everything said about ductless ,I own an AC company for 25 years and we have gone from installing central systems (unitary) to 80% ductless as part of our business.
    Ductless technology is here to stay,less maintenance ,more reliable,more efficient,no energy loss
    The comment made about central system leaking air in a condition space is very rare,must duct work are up in the attic or basement therefore the air is losst because is not a condition space ,refrigerant lines outside the wall,must central systems have the lines outside the wall unless is a new construction job.

  50. We live in a 2,000 square foot home with 1/2 main level and 1/2 basement. Our basement stays roughly 68 year round. Our summers are hot and dry (ave 80-100 F with low RH) but cool to 40-60 F nightly). We have had a roof mount evaporative cooler for the past several years. It leaked, we had to replace the roof, and decided to install our AC differently or use a different technology. We LOVED our evap cooler. 1/2 of the main floor is a kitchen, living room, dining room combo. The other half is 2 beds and a bathroom – one bedroom is rarely used.

    We have forced air central heating so we can get a ducted AC system. The mini split seems attractive because we don’t need to cool our basement. Between these two technologies, it seems like a good deal to only pay to cool 1/2 of your home. We also wonder if anyone in the US is doing ducted evaporative systems where we could mount the evap cooler on the side of our home.

    • To EM:
      re “We also wonder if anyone in the US is doing ducted evaporative systems” — Yes.
      I lived in New Mexico for several years and roof mounted, ducted evaporative systems was the most common type of system used. Some installs were ground mount beside the house but they were unusual due to the houses (typically slab foundation) not having basements. The ductwork was in the attic and would be switched between the furnace and the cooler.

  51. Hi. Was wondering if you could give me a suggestion. I’m making a room in our attic (in upstate NY). We have a normal stairway that goes to the attic with a door on the bottom of the staircase. If I install a ductless mini split right above the staircase, would that be ok? Or will the cavity of the staircase “eat up” all the cold air and the room will remain hot?

    Thanks so much for your help.

    • Hi Aron – You could experience problems with that location for a mini-split in that the cool, conditioned air coming right off the coil may flow down the staircase into the lower floor (cold air flows downward). Similarly, if it was in heating mode then the warm air would tend to rise and stay in the upstairs space. Mini-split systems are designed to condition a space (one room or two) and the air flow does not reach much beyond that. You might want to try moving it away from the stairway or add some other means for air movement (e.g. a ceiling fan) to compensate. You can ask a few contractors about it to make sure. Without being on site it is difficult to consider all the other factors that might be affecting your comfort in this area.

  52. The ductless Mini Split is very easy to install, and in China, the installation is free when you purchase the system. And it only take two technicians less than two hours to complete the job. This is definitely a DIY job and I don’t believe any of these guys got A/C certification on this type of installation. It’a just about drill holes, and connect pipes. They got training at the factory like Haier or Gree. If the installation labor cost will be as high as in the US, I think most Chinese will do the installation themselves. http://item.gome.com.cn/9134265716-1123200734.html?cmpid=ad_it168_cpk_3_o_2_o_20141231_o_o_o
    This Gree model cost $500 with installation included. I guess here HVAC guys just gouging the consumer for such a low-skilled job.

    • Agree. Obviously the AC industry here is pushing for big, complicated central systems that clearly need pros and more importantly, license, to do the work, and have them gouge the consumers. It is ridiculous in 2017, the US is still installing giant noisy window units as the alternative, when split units are quiet, efficient.

  53. I live in a house that’s about 3500 sq ft. We have 2 separate A/C units, 3 ton and 4 ton – Carrier. The 3 ton condensor died about a month ago and I’ve been getting bids. I’m thinking of going to a heat pump since there’s only about $1k difference from straight A/C to Heat Pump. I also got a bid for a ductless system.

    The bids I got for an American Standard Platinum 3 ton unit ranged from $9500 to $24,000. The 9500 guy didn’t even come out and look at our house while the $24,000 guy must have had his head up his . The two middle quotes were for $12,040 (without any modulators) or $14,500 with 3 zone modulators and Thermostats, and $18,650 with a couple of rebates that bring it down to about $15,500. Then I got a bid for a ductless Mitsubishi with 5 heads (we have 5 bedrooms) and that was $21k. I almost choked. $6500 MORE from a ducted system to a ductless system systems to be very far out of wack. I told them I didn’t want it to be solid gold.

    I’m struggling with which one to use… These prices are crazy. If I had the time, I’d do it myself.

    • What a rip off, Carl,

      These systems are almost stupid easy to install. We have installed four very inexpensively. My experience:

      We have two Halcyon units in our home in GA. We had three until about 10 months ago (see below). We are generally displeased with them because of the extraordinary amount of cleaning they require. The indoor units get moldy very quickly. Then they constantly spew mold spores all over the room. The coils and fans become very moldy and nasty. We are on a schedule to clean them every 4-6 weeks. It’s an ordeal to clean them. We have to remove the cover, drape plastic underneath the unit to guide the cleaning solution and rinse water into a trash bin. The mold gets attached to the coils and fans and can only be removed by fairly high-pressure water. High humidity probably exacerbates the problem.

      The mold these units spew have caused health problems for my family and pets. I estimate that we’ve spent a few thousand in medical bills as a result.

      When we asked Fujitsu about the mold issue, the said that we should hire a contractor to come clean the units regularly. Imagine spending $200 a month to have someone clean these units!? That will eliminate any costs savings you might expect from reduced electric bills.

      The 9RLS system has a serious temperature control issue, as well. The indoor temperature sensor is located right on top of the evaporator coil, so it’s influenced by the coil’s cool temperature. Usually when we set the cooling temp to 64F, it would stop cooling when the room was about 74F. Finally, after years of struggling to get it to cool the room, I removed the sensor and routed it outside the unit so it is exposed to the room air behind the unit at the top. After this modification, it will will FINALLY cool the room effectively.

      Overall, not a wise investment.

      We replaced one with an LG unit about 10 months ago. Amazingly, this LG unit stays clean. It’s one with the self-cleaning setting. It is SO much better than Fujitsu. I plan to eventually replace the other Fujitsu’s with LG units.

      The unit we like: LG LS120HSV4

      • We live in CA but have grandkids with asthma.. I am sure our general humidity levels are way less than GA but hearing about mold spores really is a scary point… So no issues with your installed LG?? As far as mold???

    • Hi Carl,

      We do recognize prices for equipment and installation can vary greatly. While we do encourage multiple quotes from contractors, it can be confusing sorting out the differences and options of each offer. From the ‘side by side’ comparison point of view, it would be important to understand the efficiency levels, features, installation/labor costs and warranties being offered.

  54. I live in St. Pete FL. My house is only 900sq.ft.. I currently have a ducted HVAC over 15 years old, and it will need to be replaced very soon. I have the original ducts, and they are metal. I’ve had some companies tell me I need to replace those when I get a new system, yet others tell me they are fine, and just need to be sealed for leakage.
    I’m confused, and the pros and cons here, have not cleared that up.
    Should I just replace my system with the same, or will the duct-less split system (I have 6 vents) be more cost effective in the long run.
    I’m on a very restricted budget, and the cost is a big factor.
    Thanks for any and all assistance.

    • Hi Mary,

      A few thoughts. Get quotes from different contractors for both system types and for different brands (although we can’t recommend any brands or contractors on this site – you should shop around to get offers that fit within your budget). You might try getting referrals from people in your neighborhood who have a similar home design. There are tradeoffs between ducted and ductless and would encourage you to ‘word’ search the threads on this site to learn more.

  55. Mini-splits offer pros and cons, most of which have been dealt with in these comments. The only thing I’d add is that I installed mini-splits in my house in the Lesser Antilles (Caribbean) for approx 30% of the cost I was quoted here in the USA. Make of that what you will.

  56. A regular fan with icecubes behind it works way better than all minisplit or central ac systems, you’ll also save a ton of money on your electricity bills. You may also want to switch to geico to save a few more bucks.

  57. I have a summer cabin in NW Iowa with no heat or a/c. Here it’s sometimes hot but pretty reliably very cold in winter. Can be below zero for several days at a time. No natural gas in this area.
    Would like to extend my time at the cabin. Plan to insulate and finish walls w car siding. Considering Mitsubishi ductless mini-split.
    Currently have to drain water from all the pipes before winter. After doing this ourselves for years (poor outcome), am having cabin winterized at cost of $150 Fall and another $150 to open in Spring.
    1. Would a hyper-heat Mitsubishi unit, run at its lowest setting (50) in January when I’m not there, be enough to keep water from freezing?
    2. If no, would baseboard heating in basement be enough to keep water from freezing?
    3. Is it likely that $300 savings from not having to out the pipes would cover cost of running mini-split all winter?

    • Hi Carol – You might want to ask your HVAC contractor if the mini-split at 50F would have enough air flow to keep your interior pipes and drains above 32F. This might be affected by other aspects like the amount of insulation and the location of both the indoor blower unit and your water pipes. Mini-splits are designed to circulate conditioned air within a specific space so placement of the indoor blower units could be critical. You can also ask the contractor to provide an energy comparison for mini-splits versus baseboard heat in the areas where you have plumbing. Depending on the size of the space and other aspects (above) I think you might find it to be less expensive to winterize the plumbing relative to running the heat all winter but a contactor should be able to do the measurements and calculations to tell you if it will work and about how much it will cost.

      I hope this helps to answer some of your questions.

  58. This is the one of the most biased articles I have read on the subject and just have to comment. Having built and lived in several radiant heated homes since the 80″s I have used mini split systems as as my number one cooling option. The benefits of duct free radiant heat FAR outweigh any typical forced air system available. I have found that if you build your well insulated home properly from the start, you should hardly be using your AC in the first place. Not much research in this article, and I doubt the author has lived in a home with a radiant / mini split system for any length of time, if at all. I’m suspecting a hidden agenda.

  59. I absolutely love my dual mini split system. When I renovated the beach house this was my system of choice. The cottage has three bedrooms off the open living area. Both air handlers are strategically located in the living area with ventilators to the bedrooms. I couldn’t be happier. The system is very quiet…you don’t even know its on, unlike conventional systems that come on and off blowing hot and cold. The system is economical and efficient. I can’t wait to have this system installed in my main residence. As a realtor I have the advantage of viewing a lot of homes. Recently, I was showing a property that had the mini split system installed. It was an older 1930’s, 6,000 sq’+ home. The air was off when we arrived and the house was uncomfortably warm (outside temp 90+). I was so excited to see this system in such a large home, I couldn’t wait to test it out. Every room had 1 air handler, and the rooms were grand. As you entered each room there was a remote mounted….so simple. Just point and click. It only took a few minutes to cool down the house. By the time we were finished looking at the first floor and heading upstairs….it was also cool and comfortable. Needless to say my clients enjoyed the home and were impressed with the system.

  60. I am curently considering a putting ac in my 1600 sf home. I have a forced air heating installed and wanted to install central ac. i have floor and wall supply and return registers. Will air be distubuted correctly or should i think about a split system? Does anybody have central ac with floor registers? and if so how good does it work? Any advise will help thx.

    • Hi Curtis – It is pretty common practice to use floor and wall supply and returns especially when AC is included with a gas forced air furnace. You might want to talk to several contractors just to make sure you are all on the same page though with the expected air flow, system capacity sizing (BTU/hr) for your space and also the placement of the returns. It is also pretty common for people to add central AC to a system that already has ductwork but you can quote it both ways to check. Whole home airflow, air filtration and humidity control are usually better with central AC though.

  61. No I don’t burn candles, but thanks for the info. BTW, do you think cleaning the blower wheels annually is what you are hearing from others who have purchased mini split systems? I read through a lot of the posts but did not see anything addressing this issue. I can’t tell if my situation is typical or unusual.

    • I believe yours was the first post I have seen on our site about cleaning the blowers. We can keep watching for more on this to see if others are experiencing similar problems.

  62. Hi Frank,
    As a follow-up, I contacted the manufacturer of my mini-split system and they recommend cleaning the blower wheel annually. Unfortunately for me, the maintenance contract I purchased from the contractor who installed my system includes cleaning the coils and blowing out the drains but does not include cleaning the blower wheel! This is an extra charge! This would have been good to know in advance since the cost to clean the blower wheels for my 4-unit system is $340. So much for cost savings!

    • Hi Doreen – I had one other thought on this. If you frequently use candles in your space this might also be adding to your problems. We have heard of situations where the smoke from burning candles has led to problems with HVAC filters. Just thought I would pass this on. No need to reply.

  63. In April, 2014, I purchased a ductless heating and air conditioning system with 4 evaporators and a heat pump to replace my window unit air conditioners. I have a 2-story, Dutch Colonial in Connecticut of approx. 1,800 sf. which includes an attached family room on the first floor. I priced central air and the Mr. Slim ductless system from multiple companies and consulted with several realtors before deciding to go with the ductless system rather than give up my closet space. I love my system and love the option of turning my units on and off as needed to conserve electricity. I also purchased the annual maintenance contract and have my units serviced every year and wash the filters monthly as directed. During my annual inspection in July, the contractor told me that my blower wheels were dirty and needed to b e cleaned on three of my units. I was told this was not normally the case, that most units can go from 5 to 7 years before the blower wheel needs to be cleaned but they could not tell me what I could do to correct this situation, other than to purchase a barometer to see how much moisture I have in my house. I run one unit downstairs from the time I get up in the morning at 75 degrees at a high (but not the highest) fan speed until I go to bed, then turn the unit off. Then I run the two units in each of the 2 bedrooms at 75 degrees, same fan speed from the time I go to bed, until I wake up. What am I doing wrong and, what can I do differently to prevent a build-up of dust and then mold from happening on the fan wheels? Beside the fear of mold blowing into my house, I also did not anticipate the added expense of having to clean the units so frequently. Should I run the units continuously at a low speed to prevent the blower wheel from collecting dust? Should I get a dehumidifier? Does this mean my windows need replacing? My house is very clean and I no longer have any wall to wall carpeting, just hardwood floors. I never noticed a lot of humidity in my house, but the windows are the original. Is this just a function of this type of system that they don’t tell you about? Please help.

    • Hi Doreen – All homes will accumulate dust over time, even with hardwood floors and the addition of higher humidity (often in basements or lower levels) can cause additional problems. As noted in several posts on this article, humidity control, air filtration and whole home air circulation are often cited as being compromises relative to a central, ducted AC system with a large air filter and higher airflow between rooms. While there are many advantages (like zoning) that you get with mini-splits we have heard of people using dehumidifiers, stand-alone air filtration systems and fans (ceiling or box type) to help with these compromises. In addition, you might also try running some of the units at a higher temperature rather than shutting them off entirely during the more humid seasons. This might avoid a build up of humidity in those areas. I hope this helps to answer some of your questions.

      • Thank you for your response. I am disappointed to learn that this is just a function of this type of system which I was unaware of when I decided to go with the ductless system. I will try to run the units at a higher temperature vs shutting them off at night when it is especially hot and humid. In retrospect, I might have done better with central air in my home.

  64. Frank, Great article. Thank you for responding to so many questions. The comment section is equally informative. My question is regarding the noise made by the outdoor compressor, and its minimum allowable proximity to the building, that won’t void the warranty. I have a bad neighbor who might complain, and demand new equipment be torn down, if it is placed within the 13 foot wide area between my small old Cape Cod, and his new McMansion. Is the compressor quieter than my existing low-cost window shakers? If it is *noticeably* quieter, he might not complain. If I can keep the compressor within 18 inches of the house, okay, otherwise there might be an easement violation, and I won’t be granted the building permit. I could position the compressor behind the house, and have plenty of room. But that would negate any benefit of this type of a/c. Routing the refrigerant lines would become the problem. I might as well get a full set of ducts with central-air installed in my radiator-heated 1100 SQFT solid brick Chicago-area house. Alas, my original plan to get a brick mason to cut holes in the wall, install a lintel, then get thru-the-wall A/C units installed, might become reality. (I like casement windows!)

    • Hi Greg – I would check the OEM sound performance ratings and compare those to the ratings for your window unit. It is possible that they might be lower on the mini-split but it might also depend on the size of the units and how they are mounted, etc. I am also not sure about the space constraint relative to the OEM placement guidelines (distance between the outdoor unit and the exterior wall) so you might check that as well. The 18″ clearance seems a little tight for the overall dimensions of the unit to allow for enough airflow so you should contact the OEM or the contractor doing the installation about that. I hope this helps answer some of your questions.

  65. Why do they not want to use split system? Money, that’s why. Like many things in the United States, they are manipulated to milk everyone’s hard earn dollar. Let’s see, medical, HVAC, oil, etc. When an AC tech tried to charge me $300 to replace a $15 capacitor, you know something is up. Afterall, that is the American dream.

  66. Hi, Frank,

    Awesome site!
    As everyone here, I’ve been debating between split system and central.
    Our home, in Southern California, is 2000 sf, 65 yrs old ((built in 1951) with central original forced air heating. The furnace was changed about 15 yrs so, for this area, it’s still fairly new.
    When I asked for proposals for a new central HVAC unit I had some contractors telling me that I have to change the duct work while another said that it could be left, just add insulation.
    Of course that difference was reflected in the cost. Who do I believe?
    Another question: Isn’t more efficient to hire a mechanical engineer to design the system and then, based on his plans and calculations, request proposals? It seems a better way to really compare prices, apples to apples. The cost should be between $600 & $800.
    This would require a preliminary decision on the type, split or central.
    Thank you in advance for your advice and for this site.

    • Hi Cristina – people do not always replace ductwork when they add AC to a central, ducted furnace. Sometimes the contractor has to retrofit the indoor coil above the indoor blower but that does not mean you have to replace all the ductwork. Unless your ductwork is in really bad shape (leaks, blockages, very dirty, etc) or if you want to reroute it or add zoning to it you might not have to replace it. We always recommend getting a couple different quotes before deciding on a contractor, not only to get a good price but to make sure you and the contractor are on the same page with things. You might also want to consider a central AC heat pump AC which can run as a heater in the winter and might save you on energy costs.

      It is not typical for homeowners to hire engineers for HVAC replacement decisions unless the sutuation is unique or very large. The cost for that service is high relative to the cost of the equipment so most people just get different opinions from various HVAC contractors instead of hiring a few based engineer. The objective opinion you might get from an independent consultant would be good but most people in existing structures just do their own research. Some people hire consultants for new, custom construction though. I hope his helps to answer some of your questions. Thanks for visiting our site!

  67. My wife and I are trying to decide whether we should get Central AC or a Ductless AC UNIT. We live out here in Cabazon Ca, and the hottest its gotten is about 216. So it gets pretty hot. right now we have a roof mounted Swamp cooler that doesn’t do much. Our home is only about 1200 sq ft. We already got a quote through Home Depot and they gave us an estimate for Central AC at about $20,000. Crazy right…. and the estimate we got to have the Ductless installed is floating between $8000 to $13000 to have that installed. We don’t know what to do. Its a lot of money and I’ve notice that the ductless AC units sell from about 2000 to 4500. We’ve been told that we’re getting charged way too much. And we’re first time home owners with 2 kids, and one of them has been through 2 heart surgeries. So we really don’t want to keep having our children seating all throughout summer. Any advice? Anything would help and would be greatly appreciated!

    • Hi James – We usually recommend getting several quotes from different contractors for the various system types before deciding. This is not only to get the best price but also to make sure you have a contractor that understands your particular HVAC problem and is on the same page with you about how to fix it. Mini-splits have an advantage in that you can add them one room or a “zone” at a time to keep your initial costs low. If you really want the lowest up front cost you can also try to use window (or “room”) air conditioners that you can install yourself as a way to get some relief. You can also try a hybrid approach of DIY room AC”s and a mini-split with some ceiling fans to keep the air moving between the units. You can get room AC’s at any major retailer. It would still be good to get some input from various contractors on the various approaches including the central AC option – even if it is a few years out before you install one. I hope this helps answer some of your questions.

  68. Hi Ron – it is still pretty common to put the vents in the floors for an AC/Furnace so I would get the job quoted a few different ways from different contractors before deciding. With any system it is very important that the contractor size the system right for your space so it can keep up on the hottest and coldest days. For example, if the second floor is an issue your system might be sized to small for your house.

    1. You can add mini-split heat pumps to run with your existing system and just keep your furnace for the coldest periods when the heat pumps are not keeping up.
    2. you can abandon your existing AC/Furnace and go with all new mini-split systems but you might need a few systems configured around your house to get it all cooled and heated. If you do this I would keep the central blower unit and filter to keep the air moving among the various zones you have with the mini-split
    3. you can just replace your central AC/Furnace with a new one that probably be higher efficiency than what you have currently. I would also look at an AC heat pump to go with your replacement furnace and I’d also look at 16 SEER or higher if you want the best comfort and efficiency.
    Remember to have the contractors do the calculations to make sure you have the right capacity and make sure they install the new system properly. Even the highest efficiency systems with the latest technology will not run well if they are not installed right. You might also have the contractor look at your ducts – maybe some could be added to help with your comfort. I hope this helps answer your questions.

    Thanks for using our site.

  69. I have an early ’60s house that was build for central heating, not AC. The vents are all on the floors and the ducts — in the basement and walls — were designed for the gas heater. I have never been able to get the 2nd floor cooled sufficiently for comfort during the hot Mid-Atlantic summers. Now the central air seems to be deteriorating. There is a refrigerant leak that cannot be identified and repaired. My thought was to replace the central system with a 2 or 3 Zone min-split AC (only) system rather than replacing an inadequate central system. I have to consult to be sure, but I believe such a system would adequately cool the main and upper story and the basement would remain cool enough as it is underground. I would appreciate and thoughts and feedback others have on this situation.

  70. I’m a mechanical engineer and specify/design HVAC installations for multi-family, commercial, and industrial projects. I typically have a mix of both ducted and ductless systems on projects and I like them both. Reading alot of these comments about people wanting to switch over to whole house ductless systems, I think my biggest concern for people making this choice is that they may not understand the outside air requirements of the various building and mechanical codes and how a lack of outside air effects indoor air quality. While some ceiling cassettes support outside air connections, I am not aware of any high side wall units that do. While there are alternatives to using a central heating and cooling system to bring in outside air such as exhaust only ventilation and natural ventilation, under the newer building codes (2015 I-codes and 2015 Uniform codes) this is getting harder to achieve. While some jurisdictions will allow retrofit work that replaces a non-compliant system with another non-compliant system, most jurisdictions will require that if the HVAC system is replaced that the new equipment installed needs to meet current requirements. In your jurisdiction does require retrofits to meet current standards then many homes are designed such that a purely ductless installation can’t meet these requirements. Take the 2015 IRC (residential code) for example. This code requires mechanical ventilation for any space further than 25′ from an operable opening to the exterior, even if the opening is sized to accommodate natural ventilation for that space. This means that if you have a central room (or space in a room) more than 25′ from adequately sized windows you can not meet the outside air natural ventilation requirements in the code without either providing exhaust in that space or ducted outside air into that space. If that space is served by a high side wall ductless unit, then any outside air ducted into that space will enter the space before being adequately conditioned which can lead to problems with temperature and humidity control. I’d highly suggest that anyone considering switching to a ductless only system spend sometime reading about outside air requirements and how outside air effects indoor air quality. There is nothing worse for a developer/contractor/owner than to get to the time for an inspection and have the inspector reject the installation and be forced to do it over or add additional equipment before getting signed off. I have seen this happen multiple times when the outside air design is inadequate and fails to meet the code in effect. I have also dealt with many contractors who completely ignore the outside air requirements on work they do themselves that was not designed by a engineer. Just my 2 cents.

  71. Hi again. the indoor head of the mini split system I want to install says there needs to be a 6 inch space between the top of the indoor unit and the celling. Any guess as to whether I can install it against the ceiling if my celling slops up and away at 35 degrees? (There is no vent in the top of the unit and the louvers direct the air down onto the room.)

    now thats it, really!


    • I think that space might be required to insure proper flow of warm air (hot air rises) from near the ceiling of the room rather than pulling it from below. Even though there are no louvers on top it will need to pull air in from an area/volume that is above the center of the unit and if that volume is restricted it might not provide as much cooling. There might also be some design clearance for maintenance access but not sure. Might check with the OEM. thanks for using the site. I hope this helps to answer some of your questions.

  72. Tried to read all the stuff above but still have a question.
    The larger btu mini-split systems allow for longer lines. 35 ft. compared to 60ft. for instance. If my lines are insulated can I run a longer than recommended line on a smaller btu unit?

    Or, What determines how long the lines are?

    thank Kent

    • Hi Kent – the line set determines the amount of refrigerant “charge” you need to put in the system (the lines need to be full). If you get too much charge in the system relative to the size of the sump in the compressor you could get liquid refrigerant migrating back to the sump which might damage the compressor. The oil in the compressor sump might also get washed out and diluted into the long lines which also could damage the compressor. In any case we suggest you stay with the OEM guidelines for line lengths which are related to system (and compressor sump) capacity.

  73. Hi everyone

    I have to replace my 30+ year old gas forced hot air furnace with either a new gas furnace or 6 individual Mitsubishi mini splits.

    There is currently no air conditioning but I would like to add it to avoid 4 window air conditioners.

    The problems I am having with the gas furnace install seem to be forcing me to the mini splits.

    There doesn’t seem to be a way to vent the PVC pipe outside because it would be under my deck that is a used seasonaly and semi closed in. This would force me to buy a less efficient furnace and use the chimney.

    The returns are on the outside walls and there are not enough of them and none on the second floor. More would have to be added and the current duct set up is in poor condition.

    Can’t install an air handler in the Attic because the second floor ceilings are a flimsy old tile and not sheetrock. Mass save won’t even add more installation because of those tiles.

    There is also no place to put the air conditioning unit outside on the furnace side of the house.

    I feel like my best bet is the mini splits but why am I being told it’s cheaper to install 6 individual units instead of two multi units on the outside?

    Can I really heat my entire home comfortably with these and what do I do with the bathroom that’s always closed?

    Should I find a way to install a furnace or use the chimney with a less efficient furnace?

    I live in Massachusetts. Looking to keep it under 10k after rebates if possible Any suggestions or feedback would be helpful. Thanks!

    • Hi Ron. Here are a few ideas you might discuss with some contractors. You could consider a low efficiency central, ducted gas furnace and a heat pump air conditioner. This is called a dual fuel system in that you can use the electric heat pump in the fall and spring but you would still have gas heat on the coldest days and nights. This would give you AC benefits too. The contractor might have to run the refrigerant lines to where your outdoor unit is located but that is possible. Some contractors also can fix up your ductwork too and maybe add some drops but you might have to ask around until you find someone who can figure this out for you so it might take a few calls.

      Once this is installed, if you still have some hot or cold spots you can add one or two single mini-split heat pump units to help in those areas.

      There are advantages and disadvantages of central HVAC and mini-splits and these appear in this post and a few others on this site which is searchable. You might check out some of the discussions about heating issues that far north. In any case, make sure your contractor gets both the heating and cooling capacity calculations right for whatever system you decide to install.

      I hope this helps answer some of your questions.

  74. I currently have gas forced air heat in my home. I have a 2500 sq ft home in the Pacific Northwest. The past 2-3 years the summers have had several very hot days that make the temps in the house reach 85-92 degrees. This is becoming unbearable but I’m at a loss at to what is the best option to try and cool at least part of the house. Electric costs are extremely high here so energy efficiency is a must. Also as a single person with a moderate income it needs to be financially feasible also. Any suggestions? I literally know nothing about this type of project and what to expect.

    • Hi Patricia – I am sorry. I thought I answered this post a while ago but noticed it did not make it for some reason. If you are still looking for a solution I might suggest a few options – a “window” or “room” air conditioner can be purchased from many consumer retail stores and installed with a few simple tools. It requires some lifting and hand tool work usually. This would be lowest cost to buy and is small enough that it does not use much energy but it also does not cool a large space. If you don’t have a window you want to give up for a window AC then you might try what is called a Packaged Terminal AC unit or “PTAC”. This is the type used in many hotels. It is like a big window AC unit but it installs through a hole in an exterior wall. These are a little more expensive and would require a contractor to create the hole in your wall and also install it and set it up. I hope this helps to answer your questions. Sorry if this is too late.

      • Frank, why would you recommend a PTAC over a mini split? That makes no sense at all. A mini split is much more comfortable, efficient, and quiet. The cost is competitive, and you do have to cut a massive hole in your wall, only a 3″ hole.

        • Hi John – I believe this about my response to Patricia who said she was in the Pacific NW and only needed cooling “2-3 day”s out of the whole year and she was also concerned about the initial up-front costs. I agree that a mini-split would be a better option from a comfort/efficiency standpoint but a window unit or a PTAC might be lower cost for her. I probably should have suggested that she get quotes for a mini-split too but was really focused on a solution for just a few days. Good catch. A heat pump mini-split might also be a good, multi season solution for Patricia. Thanks for using our site.

  75. Thank you for this great site and to the many commenters for providing their perspectives.

    I’ve lived in six different countries (other than the U.S.) over the last 25 years and have used split systems in all of them. All the systems kept me comfortable, even in Pakistan and Japan, where the summers made Florida look like the Rockies. The only downside to the split systems was that they seemed to require more maintenance visits that the central systems I’m used to in the U.S. Wall units would start making funny noises, or start dripping a little, or get a musty odor. The fixes were always easy, whereas I’ve found central heat and air repairs to be fairly pricey but relatively infrequent.

    I am looking to replace PTAC units in my high rise condo with either a split system or a fast air (the kind with the tiny ducts) central system. If I go with a central system, I will lose a closet to a furnace, which is causing me to lean toward a split system with integral heating elements.

    Installing central HVAC would mean dropping the ceiling in the hallway and installing special crown molding in much of the house, other reasons I’m leaning toward a split system. Nevertheless, thanks to what I’ve learned here, I’m going to get multiple quotes on both types of systems.

    Let’s face it, either way, I’ll be in heaven not dealing with the ugly, noisy, inefficient PTACs anymore!

  76. Thanks for this incredible dialogue.
    I have an issue I believe is somewhat unique. My 38 year old 2800 Sq Ft home has two central AC units with gas heat that are as old as the house. A trusted contractor stated that my upstairs unit is on it’s last legs and in need of replacement. Problem is that the (upstairs hall) closet within which that unit resides is not large enough to accommodate new replacement gas units to code. I could replace it with an all electric unit but would have to run 240 from box on other side of the house without attic space for the run due to cathedral ceilings along the run. So I perceive my options are to 1) go all electric and run the 240 through ceiling having to replace the ceiling along the run, or; 2) rebuild and enlarge the closet by stealing space from bedroom to accommodate new gas heat (to code), or; 3) go ductless for entire upstairs (which is serviced by the existing unit) – 3 bedrooms and 1 bath which spans the entire second floor. Wife and I are empty nesters and upstairs is used for guests primarily. Assuming I’ve tagged all the options correctly, my questions are:
    1) which option would beget highest resale value
    2) which option would be least expensive to replace existing unit
    3) which option would be result in lowest overall maintenance

    Thanks again,

    • Hi Jim – Here are some thoughts: At 38 years old, your system has had a long life. Most systems in the US only last about 14 years on average before they are replaced so you might look into replacing both your systems at some point.

      Location is pretty important in determining your needs for AC cooling versus heating but I will assume you need both for now. There are some advantages to staying with your existing ducted central system and these are explained on this article and others on this site so let’s start there. I am not sure if the size problem in your closet is being driven by your furnace or the AC but in any case, one option might be to get a smaller system that fits and then add a mini-split to replace what capacity you lost with the smaller size. A heat pump system would not have a furnace and that could be an option too and this might address your space problem if it really is being driven by the furnace.

      You can look into mini-splits but I think you will find that you need several of them to condition that space. These will require one or more outdoor units and at least that many indoor units and these will each require power drops – at least to the out door units. You might also need to run refrigerant lines from the outdoor units to the indoor units and this could present a problem similar to the one you mentioned with the power lines.

      On the resale value – ducted central systems are pretty common in suburban and rural areas but mini-splits are becoming popular. You might check with a realtor in your area about this.

      On the expense – we always recommend getting multiple quotes and you might ask an electrician about the various power drops you are considering along with a carpenter to help with the sizing of various systems in the closet. Also, by upgrading to a new model you will get some energy cost savings from the improvements in efficiency over the past 38 years so Io would ask your contractor about that as well.

      On the maintenance – it is tough to beat a system that has been running for 38 years but you can ask the contractor about the expected life of various options and whether they can be easily repaired as there are different opinions on this.

  77. Installed two of these myself with no prior HVAC experience, simple to install, far superior to central AC units. I can see why HVAC contractors do not like these, not much to go wrong with them. They cant keep coming back to your house to soak more money out of you doing yearly checks, duct cleaning etc. I will never let a HVAC contractor into my house,

  78. ductless mini-split sadly are synonym of third world.
    They are frankly a s**t !! In Panamá (Republlic of Pamamá) we mostly use this crap and is an eternal pain, ultimately in EVERY installation of my knowledge (my own condo, family, friends), the condensation of the refrigerant lines accumulates to the point that the roof of the neighbours get that nasty water and mold mark along the refrigerant routing.

  79. Frank, I am replacing a 40 year-old boiler and duct-ed A/C unit in a 2600 sq ft home. Besides the problem with their age, they are both extremely noisy. A contractor recommended a mini-split system for the A/C, saying it would be far quieter than a new central A/C. True?

    • Hi Dave – Here are a few thoughts. First on the boiler – hot water/steam heat has a lot of advantages (comfort, even heat, efficiency, etc.) and if your home already has the piping installed for this type of heat it might be worth just upgrading the boiler and the delivery pump rather than removing all that expensive piping, radiators, etc. I have hot water heat in my home and I really like it. You can get some pretty efficient natural gas replacement boilers but you should find a contractor who specializes in boilers and is good at this technology before deciding this. Not all HVAC contractors service all system types – boilers, furnaces, mini-splits and AC/Heat Pumps. You can ask a few boiler contractors about the noise problems as maybe these can be addressed with an upgrade of some of the
      boiler components.

      One other point – your heating decisions might depend a lot on where you are located and whether you are going to keep your boiler heat. If you keep the boiler then you should definitely consider an AC system that features a heat pump option which allows you to run it as a heater in the winter seasons. You can then run the heat pump in the fall and spring and use the boiler in the coldest days when the efficiency of the heat pump falls off. When it is really cold out (below 15F) there is not enough heat energy in the ambient air to efficiently pull it back into your home with the heat pump. So, if you keep your boiler I would look at a heat pump to go with it. If you abandon your boiler and go with just a heat pump I would ask your contractor about energy costs on the coldest days (if severe cold is an issue where you live).

      On the AC question there are a lot of points on this site – both pro and con for the use of mini-splits. One theme we have noticed is that if you already have duct work in your home and it is in good shape (no leaks or debris, etc) then it might be less expensive to just replace your central AC system (perhaps with a heat pump option) than it is to abandon your ductwork and run new refrigerant lines to all the indoor units which will hang on your wall or ceiling. While air flow and filtration might be challenging with mini-splits, some people go with them if they want to totally zone off different rooms in their home to save energy.

      On the question about noise – I have a two stage central AC systems that is very quiet when it is on low stage, which is most of the time and almost every night even in the summer. I only really hear it when it runs on high stage on the hottest part of the hottest days or when I turn it on after it has been off for a while. Mini-splits can also be very quiet but as you can see from some of the posts on this site, they are on the wall in your living space so any operating noise will be heard by the nearby occupants. However, some people say they are very pleased with how quiet they are. This might be a point of personal preference or based on what they are comparing. Any system type – window units, through the wall units (like in hotels), mini-splits and some central systems can be quite loud when they turn on and off. If noise is a real concern I would ask a few contractors about this so you get the right system and have it installed so that it minimizes sound. I would definitely ask about a two stage (or variable speed) central AC/Heat pump system which would be very efficient and very quiet when it runs on low stage.

      It is especially important for you, since you are considering so many different system options, to talk to a few different contractors about all the different system options and have your job quoted with all the different options before deciding. Prices vary from contractor to contractor and from one OEM system type to another. Installation can also be a major part of the overall cost for your replacement project so it is important to get itemized quotes. I hope this helps answer some of your questions. Good luck with your HVAC project and thanks for visiting our site!

  80. I am in the process of finishing my basement and want to get the AC issue out of the way first (I say AC only because my basement is heated year-round by a natural hot-spring that run beneath — average temp of the floor is 92 F — It’s cozy in the winter, but it’s unusable in the summer and even storage down there concerns me). I’ve had three contractors in and am waiting for bids. Only one of the three suggested ductless splits but they seem like they might be the best solution to my situation. The other option (from what I’ve been able to research) is a zoning setup of some kind. The down-side (again from what I’ve been told) is that dampers tend to fail fairly regularly and the complexities of ducting, etc. can be expensive and somewhat unreliable. My home is in Utah, is 1300+ sf up and same down. Any comments? They would sure be helpful.

    • Hi Bill – It is not clear from your post whether you are replacing your whole home AC system or just dealing with the AC in the basement separately. I will assume that you have decided to separate the basement from the rest of the house but if this is not the case you can also look into a variable capacity whole home system that will allow you to zone off certain rooms or in your case, the basement. These systems are available and reliable as well as the ductless mini-split option.

      I have been thinking about your basement situation for a few days now and would say this is a fairly unique problem. Most people do not have natural, geothermal basement floors at a constant 92F. So, as with most unique challenges you are also presented with an opportunity to do something really good with it. I am going to offer the following suggestions which may or may not fit your budget but this might give you some ideas to consider and maybe some other visitors to this site can offer others.

      It seems like this geothermal heat source needs to be treated like any other thermal load on your living space – like windows with full sun southern exposure and low insulation, no shade, etc. This load estimation can be captured in the contractor’s ACCA manual J calculation so I would recommend insuring that the contractors who size the capacity for your space take this calculation into consideration before selecting the size for your new system. The other thought I had was whether you could somehow reduce the thermal (heat) load in that space in the summer when you don’t want it but let it be there in the winter when you need it for natural heating. One concept might be to put a raised floor in the basement with some insulation to thermally separate the heat source from your living space. If you leave enough room below the insulation you might be able to draft or vent the hot air out of the space to the outside in the summer through an exhaust duct but draft it into your space in the winter when you need it. If natural drafting does not work (hot air rises, etc) you might need to add a few fans to increase the flow.

      Basically, I think if you can separate the space with some insulating material and direct the flow of the hot air either outside or inside your space by shutting and closing vents you can reduce your cooling costs in the summer and your heating costs in the winter.

      You might need to engage both an HVAC contractor and a general contractor or carpenter to get estimates but given you have 97F natural heating at floor level it could be worth considering – both for the size (and cost) of your system, the energy costs you might incur to overcome the heat source and also the comfort and other benefits derived from adequately cooling and heating that space.

      I hope this helps answer some of your questions. This is a very interesting HVAC project so please let us know how you decided to resolve it!

  81. Timely ideas . I Appreciate the facts . Does someone know where I would be able to locate a fillable TREC 20-7 document to fill in ?

    • I just did an internet search on that form and some downloadable links came up. I am not familiar with the process though so I am not sure if this will be what you need.

    • If the contractor does the calculation (ACCA Manual J) which gets the cooling capacity right and accounts for the size, insulation, exposure, shade, etc in the space and also compensates for your central system and and the ceiling fan you should have enough air flow to manage the humidity. You should talk to the contractor about the way a mini split evaporating unit on the wall in your space will collect the moisture from the air as it passes over the cold coil, collects as water in the drip pan and then drains out somewhere – usually outside in the yard or to a drain. It is important to keep this drain clean and make sure it does not get clogged up and spill over. The contractor should explain how to manage this. You might also ask about getting a heat pump model that can help with heating in the winter if that is a need in your climate. Hope this answers your question.

  82. Hello-

    Can anyone comment on a mini split AC unit for a 400 square foot bonus room above a garage? The room has central ac but the ac does not cool the room. Vaulted ceiling, room faces south and gets the west sunset. So hot! New construction, minimal insulation.

    • Hi Angela – that sounds like a good application for a min-split unless your central AC system is older and in need of replacement soon. If not, I would suggest getting the space insulated and since you have high ceilings you might add a ceiling fan to insure proper airflow. You might keep the central AC ducted system going in and out of your bonus room to get the advantage of the central AC filter. You can shut it off if you are not using it – both the central system and the mini split. We usually recommend getting 2-3 quotes for the whole project to make sure you get the system sized right and balanced with your central system and the local climate. I hope this answers some igneous questions. Good luck with your project!

  83. Now that hotel-style heat/AC units (PTAC’s) are available with heat pump technology (PTHP’s), might this be a cheaper alternative to mini-splits in applications where a central ducted system is not possible?

    • Hi Tom – package terminal systems like you referenced are in use and perform much like window units except you have to cut a hole in an exterior wall to install a PTAC or PTHP. Mini splits do not require this large hole and the outdoor unit is removed somewhat from your living space so they have some advantages in that regard. I am not sure about the relative costs. We usually recommend getting 2-3 quotes from different contractors for both systems before deciding.

  84. Just reading and reviewing more of the comments and find it sad that contractors where I am apparently are unable to or want to do “specific calculations to determine the capacity (BTU/H) you will need for your space, considering things like the space, ceiling height, insulation, windows, etc.” When I have talked to any in the past about these things, they look at me like I’m from another planet. They are absolutely dumbfounded. I’m guessing the training to be able to sell and install these systems takes about 2 weeks in my part of the country.

  85. All these comments here about how central a/c is so great clearly are coming from people who haven’t had to spend thousands every year for 8 years on HVAC techs — about 13 — to come out and insist that they don’t know what’s wrong with your system, don’t want to deal with your ducts and that the only solution is to spend multiple thousands more to replace your system.

    I am selling a house because I cannot afford to keep it with the constant HVAC expenses. I suspect I have a leaky evaporator coil that needs to be replaced, but I have been unable to find a single company to do that. They insist I just buy a whole new system.

    As for energy efficiency, one HVAC tech would sell me $200 worth of refrigerant every couple of weeks during the summer — indicating I have a leak — but, again, would not discuss replacing the evaporator coil, only my entire system.

    I’d consider the ductless systems only because there are no HVAC companies in my area, I’m guessing based on my experience, that can fix my HVAC system or care to even try to work with me to solve my problem. I guess it’s too hard.

    Anyway, there is no energy efficiency with my HVAC since I have to keep buying refrigerant to keep it going.

    I truly feel, at this point, that everyone in any kind of business, especially HVAC, is in the business just to rip off customers. I shouldn’t have had to study HVAC myself to learn things these guys didn’t know and should have.

    So again, my issue has gotten to the point where I cannot even afford to live in my home and have it listed for sale. It shouldn’t have come to this after 8 years.

  86. Hi,
    I live in india and want to buy a mini-split air conditioner for my apartment. I have gone to a store where i met one technician. He told me not to buy the compact units (both indoor and outdoor). He advised me to buy a 3 star rated LG system over a 5 star rated unknown brand. He says that LG has much higher durability than an unknown brand (and higher price too), whereas mitsubishi is even better. I have searched the internet but there is no article which can explain the function of both units correctly and myths about so called different ‘technologies’ used in Acs.
    I want to know if my AC energy efficiency will degrade with the time, if yes can the design/quality of outdoor units helps preventing it.

    with best regards

      • Unfortunately, the charter for this site does not allow us to comment on any specific OEM equipment or any specific service providers. Also, I should point out that this site is mostly focused on HVAC systems, regulations and current issues in the North American and specifically, the US geographic areas which use some HVAC technologies that are not commonly used in other parts of the world. At some point we might expand our focus to include content about other world regions but for now, much of the content will be US/NA focused. Thanks for visiting the site. I hope you found some helpful information.

  87. Hi this is kinda of off topic but I was wondering if blogs use WYSIWYG editors or if you have to manually code with HTML. I’m starting a blog soon but have no coding skills so I wanted to get guidance from someone with experience. Any help would be enormously appreciated!

    • this site uses a product called wordpress but there are other SW packages to consider. They are all pretty easy to use once you get used to them or have someone set them up for you.

  88. Hello. I recently moved to San Diego and bought a 1280 sqft town home with no a/c and radiant heat. There are no gas lines. I had a terrible time time with the upstairs bedroom at 92 degrees at night on ocassion during the summer. Now I can’t afford the radiant heat and walk around the house in my ski outfit. I got estimates for heat and a/c for Minisplit and Central. They are about the same price, I have no ducts currently. The quotes are between 15 and 18 thousand which seems a lot higher then I have been seeing on this blog.The mini-split brand that they sell here is Fujitsu. I have 2 quotes, the third company didn’t even bother. Two questions: Which way should I go of Minisplit or Central? Should I look for other brands? I would like to get some heat in here ASAP. Thanks.

    • Hi Clara – Here are a few thoughts and suggestions. I would definitely continue to get quotes from different contractors for both system types and for different brands (although we can’t recommend any brands or service provider on this site – you should shop around to make sure you are getting something you will be happy with). You might try getting referrals from people in your neighborhood who have a similar home design. Prices for equipment and installation can vary greatly and if you have a unique installation job you might need to talk to quite a few contractors before you find one that is on the same page with what you are trying to do with your HVAC for year round comfort and not just solving a short term problem.

      Also, some people can get the price for a new HVAC system built into their mortgage for a new home purchase or added to a home equity loan – which would reduce the need for up front financing.

      On the question of ducted versus ductless there are quite a few tradeoffs listed on this particular thread and also on some other articles on this site which is searchable. One advantage of ductless is that it is somewhat “modular” – in other words you could buy one or two units now for part of your home and buy the rest over time. Still, I would get a contractors opinion on that and also how much capacity you would need at each stage and in each location in your home to insure you are going to satisfied with the whole home solution when you get them all installed.

      Good luck with your HVAC project!

  89. Hi,

    I am renovating my approx 5k square foot 1886 Queen Anne Victorian home, located in the Boston area. No existing ducting at all- it runs on steam radiators and has no AC (yet). The thing is, most of the radiators are taking up prime wall space that I’d like to use for other things- bookcases, couches, etc, and I want some sort of house wide AC anyway, so I’m going to remove most of my radiators and install other heat along with AC.

    My HVAC guy is suggesting a hybrid setup. The first floor (approx 1700 sf) would have a conventional ducted system, located in the basement, with vents in the floor. The second floor (also about 1700 sf) is still being debated, but I’m leaning towards a mini split setup. The house has a relatively open floor plan for a victorian, with a big open staircase between the 1st and 2nd floors.

    My questions are these:
    Would the conventional system that services the 1st floor help to supplement the heat on the 2nd floor during those cold Boston nights where the mini splits wouldn’t be working their best?
    I haven’t seen any discussion about the DUCTED mini splits. Can anyone run down the pros/cons of those? Especially vs the ductless ones?

    Thanks in advance for any insights! Great site and thread- very informative!

    • Hi Sig – Since hot air rises and you have an open stair case you will probably experience some natural mixing of your first floor furnace air with the upstairs rooms as long as the doors are all open, etc. You can probably augment this air flow (up and down) with ceiling fans as well. If you do this, you might need to oversize the furnace to allow for the additional heating load. Also, on the downstairs unit you might try a dual fuel approach with a gas furnace and a heat pump which allows you to get the heating efficiency benefits of the HP on the milder days but you could have the gas furnace for the coldest periods.

      If you have an unfinished attic, you might try running a second ducted system with the air handler in the attic and flex ducts to service the second floor rooms. I have not heard of using a mini-split outdoor with a traditional ducted indoor unit but I am also not sure what the advantage would be versus just using small, ducted system.

      In any case, we recommend getting 2-3 different quotes for each system type (approach) from several contractors before deciding. In your case, you might need to talk to a few before you find one that is on the same page as you and that is important. Also, irrespective of what equipment you buy, make sure the contractor does the proper load calculations for both heating and cooling in each space to make sure the unit is sized properly. I would also look at a variable speed or at least a two-capacity step system for this job due to the load matching and zoning (closed room) challenges. If the right calculations (ACCA Manual J) are done to size your units you will probably avoid humidity/air flow problems on light load days and you should also be able to keep your home comfortable on the peak cooling or heating days/nights. This would be worth discussing with your contractors as well.

      I hope this answers some of your questions. Good luck with your HVAC project!

  90. So we’re looking to build a new home in NW Washington and a lot of people are touting ductless heat pumps. Our home would be single story, 3bd, 2ba, 1952 sq ft.

    Since it’s new construction I think we could hide much of the lines in a ductless setup and it might even be cheaper than going conventional.

    What should we expect for the number and size of the units?

    • Hi Clint – The number and size of the systems will be determined by other factors besides the square footage involved. Other factors include the amount of insulation, windows and doors, airflow among the spaces, etc. A good HVAC contractor can do the calculations required to make sure your system is sized properly for your home and the likely heating and cooling demand for your area. In any case, you will probably want one internal evaporator (wall) unit in each bedroom and enough units in the common spaces to insure proper conditioned air in the whole home. We usually recommend getting at least 2-3 quotes from different contractors for both ductless and ducted system types before deciding. There is a lot of information on this site and in this article thread which explains the pros and cons for each type. If you get a chance, please send a follow up post about what you decided to do and how the numbers turned out. Good luck with your HVAC project!

  91. I am currently outside of Boston, Ma. I was thinking of getting a ductless AC/heat pump put in. One large unit one the first floor and 3 mini’s in the 3 bedrooms on the 2nd floor. The house is 1900 sq ft. My issue is that the large unit and 1 bedroom would be on one wall and the other 2 bedroom units would be on the complete opposite wall. I do have an unfinished attic but a finished basement. Is it feasible to run lines from one side of the house to the other via the attic? Do they make 1 solid run of line that long so I wouldn’t have connections to avoid leaks?

    I understand that Central Air might with ducts might be worth it but I dont know how they would get the ducts to the 1st floor.

    • Hi Will – On the mini-splits. You might consider locating the first floor unit on one side of the house and the installing separate, smaller units for the upstairs on the other side of the house to reduce the length of the lines going from the indoor to the outdoor. For multi-split systems I think you will need separate lines running to each indoor unit from the outdoor. Another suggestion, given the harsh winters you have had in Boston recently you might want to keep whatever heaters you are using now as a backup in case your heat pumps can’t keep up on the coldest days and nights.

      On the ducted option, I had the same problem with my home a few years ago and I found a contractor who could locate the indoor air handler in the attic. He ran flex ducts across the attic to the second floor rooms and ran traditional ductwork through the second floor closets to get to the ceiling of the first floor. This configuration turned out to be less expensive than ductless but prices might have changed since then.

      We usually recommend getting 2-3 quotes form different contractors for both ducted and ductless systems before deciding. Good luck with your HVAC project!

  92. I am considering purchasing a country home, around 3K square feet. It currently has a furnace running on propane. Propane is extremely expensive. I also have no desire to split wood all year round to stock up for winter for heating purposes. Would a ductless system be a feasible solution in the open spaces of the home? How many units can one condenser serve? Is a manifold system used to tie all the plumbing together? I wouldn’t want to have to cut multiple holes in the exterior of the home to plumb to the condenser…Thank you for answering what might be considered some elementary questions…

    • Hi Justin – I will try to answer some of your questions and make a few suggestions. Yes, you can purchase a mini-split that offers multiple indoor evaporators (2-3 per outdoor unit with a manifold – usually close to the outdoor unit) and these will require you to run refrigerant lines, condensate lines and power to each indoor unit. If you use this approach make sure you insulate the lines that are in an exposed, unconditioned space because tests have shown these can lose a lot of energy if they are exposed to the atmosphere. Depending on where you live you may or may not be happy with heat pump performance (ducted or non-ducted) at really low ambient conditions (below 15F) due to the efficiency degradation at those temps. One approach people have been doing in the upper mid-west is to use what is called a “dual fuel” system which features the addition of a heat pump to the existing furnace. This allows you to get the benefits of central AC and heating for most of the year but you can use your propane furnace as a backup heat source on the coldest days and nights. You might ask your contractor about this option. If you go with one or more ductless mini-splits I would still keep the propane furnace as backup for the same reason as the dual fuel approach mentioned above. In any case we recommend getting 2-3 quotes for different contractors for both ducted and ductless approaches before deciding. I hope this helps answer some of your questions. Thanks for visiting our site!

  93. Hello,
    I’m moving back to Central Florida this month to a 2600 square foot family home. The existing central air dates probably to the early 1960s. It is hopelessly inefficient. Because Florida is so humid, I definitely want a system that not only heats/and cools the space efficiently but also manages the humidity. Have been reading all the above posts with interest as I thought perhaps the ductless split system might be the way to go since so much of the house won’t be used all the time as I live alone.
    However, from what I’m reading replacing the central air system (and repairing leaky ducts if those are problems) may be smarter. IS it possible to have central air with zones controlled by separate thermostats?
    Thank you.

    • Hi Pamela – yes, there are products available today that allow you to zone off certain parts of your home and control those spaces independently. Unfortunately the charter for this site prevents us from recommending any specific product brands or service providers but you can probably find what you are looking for with an internet search. Please note, it is important for you and your contractor to know how much of your space you plan to zone off though because if you reduce the conditioned space too much you might change the operating parameters for your system and this could lead to problems like humidity, air flow and you might also be affecting the long term reliability of the system. . In any case, we recommend getting 2-3 quotes from different contractors and get them to quote both a mini-split approach and a conventional, ducted approach. Some of our visitors have also tried using a hybrid approach of keeping their ducted system but adding a ductless split to allow the benefits of zoned control and energy savings. Sometimes this requires talking to a few different contractors before you find one that is on the same page with your needs so expect this to take a little time. Thanks for visiting our site and good luck with your HVAC project!

    • Pamela: The beautiful thing about a ducted system is that each unit has its own thermostat. So you can have cooling or heating only where you need it, and to the amount you need.

  94. Frank, I have a bonus room on the second floor of my house. It is the only room upstairs that needs heating/cooling. The attic and a small closet are the only other things up there. The room is about 20×24. Our contractor recommended a separate central heating/cooling unit. But I’m wondering if we should go with a ductless system. I want to do whatever is most cost efficient. We would use this room only when we had guests…so definitely not an every day thing. Also we live in north MS. Thanks for your thoughts.

    • Hi Alana – on this site we usually recommend getting 2-3 quotes from qualified contractors for both ducted and ductless systems before deciding. Based on the description of your space, it would seem that you could use a ductless mini-split heat pump or a traditional ducted heat pump. The overall cost to you might be dependent on how difficult it is for your contractor to get either ductwork or refrigerant lines into the space, There is a lot of information on the postings for this article and a few others on the site that deal with the pros and cons of the two system types so you might consider those aspects in addition to your initial cost before deciding. Since your usage for this space might be infrequent (guest room), energy costs and energy efficiency might not be a primary concern but that also is up to you. I hope this helps answer some of your questions. Good luck with your HVAC project!

  95. I am looking to install heat & air in the bottom of my enclosed stilt home and live in high heat / humidity South Florida.
    Bedroom is 170 sq ft, the open living area is 480 sq ft. and a bath off of the living area is 75 sq ft.
    My a/c guy recommended a dual zone unit (18,000 btu & 9,000 btu). He said the larger unit would cool the bathroom.
    Does his suggestion sound about right?
    Also, in your opinion, would two separate units consume a lot more energy than a dual zone?
    Would two separate units control the humidity better than a dual zone?
    Thank you in advance for your advice.

    • Hi Tracy – Here are a few thoughts and suggestions. First of all, your contractor can do specific calculations to determine the capacity (BTU/H) you will need for your space, considering things like the space, ceiling height, insulation, windows, etc. We usually suggest getting 2-3 quotes from different contractors before deciding and these usually include the required capacity calculations as part of the estimates provided. Humidity reduction will be affected by the capacity you purchase and the amount of air flow provided. There have been some comments on this article that suggest single evaporator systems with short line sets to the outdoor unit perform better than comparable sized multi-evap units with long refrigerant line sets and some DOE studies have confirmed this. I have experienced both in rental situations but have not had to deal with energy bills. Based on the comments it seems using separate units would be simpler and might be more efficient but I am not sure – make sure you discuss this with your contractor. In any case, you should provide some sort of additional ventilation (ceiling fans, etc) to mix the air among the rooms serviced by the separate evaporators (indoor units on your wall). I hope this answers your questions. Good luck with your HVAC project.

  96. Hi Lindsy – we talked about this a bit here but could not come up with any obvious suggestions. In addition to the expansion and contraction of the materials we thought there could be an overload resetting, or a relay or some other switch chattering so you could ask your contractor/installer about that. You might also have the contractor try adjusting the position of the unit somehow or maybe put some sort of vibration absorbing material between the unit and the wall to try to reduce or eliminate the sound. These are just a few ideas for you to suggest to the contractor.

    It is difficult to say what sound is or is not normal without actually being on site to hear it. I think it would probably be good for you to keep working with your contactor and the OEM to help resolve this problem. Maybe our other readers have some thoughts?

    • Thanks for your thoughts. I would NOT have bought the unit if I would have known it made the awful clicking sounds. Seems strange that other people with similar units aren’t experiencing the clicking sounds. AARGH
      Am working with the installer and Mitsubishi but they are telling me it’s normal. Double AARGH Not sure anything will be done by either one of them. So frustrating. THANKS again.

      • Hi Lindsy,
        I have a similar unit from Mitsubishi and I can say mine does not click! If it were me I’d be insisting on a replacement.
        One thought though … I originally had the outside unit hanging on the exterior wall but I could feel the vibration so I had it moved to a stand. Much more quite. But it does not sound like this was your issue.

        • I have 3 Mitsubishi wall units and ALL of them make this horrible plastic clicking noise. The installer is accusing me of being crazy, even though I sent them a video clip of it making very loud clicking noises. I did some research of my own and I have found that it seems inherent to the system. Due to temperature changes it cracks and clicks constantly. I never would have purchased this system had I known. It is false advertising. They tout it as “silent.” I honestly can’t live with it and I am considering filing a law suit against the manufacturer.

  97. Early October I asked for suggestions on how to stop our Mitsubishi MSZ-Fh15NA from making excessive clicking noises. I haven’t heard from anyone. How much clicking noise is normal for the expansion of the plastic due to the heat/cold on a ductless?
    Mitsubishi and my installer are saying the noises are normal, I hear constant clicking for 20 minutes once the heating starts……is that normal? Any comments are appreciated,

  98. Thank you so much, Frank, I will get it rolling. I tend to agree with you to keep water heating system and get it repair if necessary. Will try to avoid any type of duct work to keep cost lower regarding the A/C. I have enough time to think about A/C. The major thing is Heating system due to the winter season approaching. Again, thank for your time and insight.


  99. A lot of good information, thanks for Frank and everyone. I bought a 1968 old foreclosure house (2700 sqft) in Metro Detroit northern side. It is Bungalow Style. The main entry direct to a large family room (FR). Left hand side of the FR, a Kitchen, a main bedroom with full bathroom, and a small study room, on right hand side, a 2 car garage. above FR, 3 bedrooms & a Full bathroom. The house is heated through a hot water system. It does not have A/C. The heating system is very old. I might run into many problems in the future. My question is 1) should I renovate the hot water system? 2) should I replace it with Ductless mini heating and Cooling, or 3) replace it with traditional ducted center heating and cooling system? what is the cost advantage?

    • Hi Andy – here are a few thoughts and things to consider. I have hot water (“hydronic”) heat in my home and I like it very much. It was not often installed in homes this far west (Ohio-Michigan) but this heat is very common in the eastern states. However, many people now are actually installing new hot water heaters in new homes today in the Midwest and it is viewed by some as being a superior heating approach to gas forced air due to using radiators instead of gas furnaces which provide blasts of hot, dry air – which tend to dry out the air in the home and also cause temperature fluctuations during the cycles.

      I also had a very old boiler and decided to replace it a few years ago. There are a lot of new replacement boilers and tank-less heaters on the market and some can be very efficient and will take up a lot less space than your old boiler system. You have to shop for a good contractor who specializes in boilers though. All HVAC contractors do not work on hot water systems so you need to call around.

      In summary, I would not remove your hydronic heating system – just consider replacing and upgrading the boiler and pump and maybe the controls if needed. I am a big fan of hydonic though so don’t be surprised if others weigh in here.

      On to cooling – I had the exact same problem with my home – an old boiler and no AC. I did not want to use window units for various reasons and had no ductwork. I got quotes on multi-head mini-splits to cool the whole house (2600’) but it was pretty expensive. I shopped around and finally found a contractor who had an idea of putting the air handler in my unfinished attic and dropping ductwork to the first floor through each of 3-4 closets and interior walls and on the second floor we used flex ducts running in the attic. I gave up some much valued closet space (typical in a 1920’s era home) but got central AC to the whole house at a fraction of the cost for multi-head mini-splits. Some people would say I gave up a lot of energy savings from not being able to zone off rooms, etc with the individual heads on the mini-splits but I did buy a two capacity system that offers very high efficiency and also allows me to shut off the kids’ rooms while they are away at college, etc.

      If I had the chance to do it over the only thing I would have changed would be to buy a heat pump so I would get the high efficiency advantage of an electric powered heat pump in the fall and winter and could delay turning on my gas boiler until the middle of the cold season and turning if off earlier in the spring – probably would have saved even more on energy with this approach and also would have gained some ability to shift from gas to electric and back depending on how the utility companies were pricing. You will need a thermostat that manages both heating and cooling with this approach. I have a wireless stat that works well.

      Back to mini-splits – if AC is not that big of a deal to you due to the short cooling season and cool summers in MI. You can consider adding mini-split heat pumps to a few key rooms which might get you through the summers up there and also give you the heat pump benefits in the fall and winter in those rooms. You would still have the whole home boiler heating solution during the coldest part of the winter which is critical for you in that area. If you do this you will need to be careful with the placement and setting of your boiler thermostat to compensate for the heating provided by the mini-split heat pumps which will be on separate controls for each indoor unit. This is not difficult to manage but you and your contractor should be aware of it and discuss it.

      There were a few posted questions last week on issues with using heat pumps in cold ambient climates like MI so you might take a look at those. Running heat pumps above 15-20F can be very efficient heating but below that there are issues with a drop off in both efficiency and capacity.

      One other thought I had was since your floor plan is basically zoned left and right you should probably take that into consideration with either the mini-split or the ducted approach. Some people with layouts like this go with two smaller, ducted or ductless systems rather than one large one. This could also help with the complications of running long sections of ductwork (or refrigerant lines for ductless) across the length of the house.

      In any case, we recommend getting 2-3 quotes from different contractors before deciding. In your case (as was with my case) you may need even more quotes since the contractor who can figure out your boiler replacement may not know much about running ductwork through a closet and neither may know much about mini-splits. You might end up with a boiler contractor and a good AC contractor for either the ducted system or the mini-splits. I hope this helps. Good luck with your HVAC project!

  100. I am converting a storage room into a small eating area. It adjoins a room that also has no heat or cooling but contains a freezer that would probably apprecitate some cooler air in the summer. . Both rooms are a 25 feet away from the nearest central ac duct. Would you recommend a window unit or a split system or could I expect enough cool air if I ran a couple of flex ducts from my existing system.

    • HI Steve. If you try running insulated flex duct to the space your system will have to run longer to cool your whole home which is not always bad – except on the hottest days. On those days (and some nights depending on your location) the additional load will cause the rooms that are the longest distance from the air handler and coil to be warmer as the system might not keep up. Basically, the thermostat will reach the set point temperature when the area near the t-stat reaches temperature but if the longest runs have not received enough cool air they will be warmer – maybe a lot warmer. If these more distant rooms are places where you spend a lot of time when it is really hot outside (e.g. bedrooms?) then you will have to set the thermostat lower to get it to a comfortable temperature in these spaces and this uses more energy. If the rooms you are considering adding are the most remote rooms then this might end up working with just adding the ductwork. If not, you might be better off just using a window unit or a mini-split system (which allows you to keep using your window) for this space.

      A certified HVAC contractor can inspect this space and do some calculations to determine if your current AC system has enough capacity to meet the needs of this extra load (cooled space) and can discuss the potential impact to the more remote rooms in your home. If your system is older, you might also consider upgrading to a system that is sized properly for this new load and you might also get the benefits of recent increases in the energy efficiencies available with new systems or even consider a heat pump or dual fuel system. Our recent homeowner survey suggests that most people replace their systems when they are 14 to 16 years old (or longer if seasonal runtimes are shorter) so that might help you decide whether to consider a new system.

      We usually recommend getting 2-3 quotes from certified contractors before deciding this as they can advise you how much longer you can expect to run your current system. If you add another system to that space and then have to replace your existing system in a few years it probably would have been better to just get the new system now – unless you really want that new space to be on its own system with its own temperature control. I hope this helps to answer some of your questions. Good luck with your HVAC project!

  101. Frank, This is a nice article. We live in north shore of boston and I have a condo-town house that is 1380 sqft (including basement) and has no ducts (no existing ducts). We have electric baseboards everywhere and our electric bill for heating the house is way too high in winter. If we had to do a duck work for the gas, it is probably about 20K and ripping the whole house apart to run the copper lines all over. We had a HVAC Contractor visit our house for Mitsubhisi ductless mini split and the quote is around 15k with some rebate from Mass Save lowering down the cost to a total of 13k for the Installation work.He claims that the quote is for a hybrid 4 head mini split heating system. Do you think we can go for a ductless mini split to warm the house cheaply in an area like boston even when it is around below zero outside or would I just end up using the electric baseboard heaters and high electricity bills?Thanks in advance for any insight you can provide!

    • Hi Prasad – There have been a few posts on this article recently that deal with the problems of using heat pumps as the only source of heat in a northern climate where temperatures frequently get below 15 to 20F. Rather than repeat that content I suggest reading some of those posts and replies. Basically, the efficiency benefit from heat pumps and the capacity (ability to provide hot air) drops off dramatically with a decline in the ambient temperature. HP’s are great for temperatures above that range though so they (both ducted and ductless heat pumps) are popular in the south. Some people in the upper Midwest have also been using heat pumps along with traditional heaters (gas furnaces and boilers) to take advantage of HP efficiency in the fall and spring seasons but keep their old heaters for the coldest periods.

      If you go with mini-split heat pumps you will probably see energy savings for most of the year but not so much when it gets really cold. We recommend getting 2-3 quotes from various contractors for both ducted and ductless systems because sometimes there are cost saving ideas associated with how they run the refrigerant lines or the new ductwork in homes that don’t have pre-existing ductwork. Equipment prices also vary from region to region and from business to business so it pays to shop.

      Some other ideas we have also heard of in situations like yours include a “hybrid” approach which might feature a single ducted heat pump for one part of the house that is easy to reach with new ductwork (either through the attic or basement) and also adding one or more mini-split heat pumps for the rest. In any case, you might want to keep your existing heaters for a couple of winters to make sure you have enough heating capacity installed. You can remove them later if you don’t need them.

      One other point I will pass on about heat pumps in places like Boston. Whether it is a mini-split or a ducted HP make sure the contractor mounts the outdoor units such that they will not get buried by deep snow. If it becomes buried in snow (or anything else for that matter – like leaves or debris, etc.) , the flow of air is restricted and it will not operate well and might cause reliability problems if it is left like that for a long time. Considering the winter the people of Boston had last year I thought I would mention this as something to discuss with your contractor/installer. Good luck with your HVAC project!

  102. Thank you for the article, and the comments. All interesting. My dilemma is that while I have forced air for my home in the LA beach area, apparently the ducts are undersized to support central air conditioning. I’m seeing a lot of questions on this thread from people in the LA area since AC was just never necessary near the beach cities: it was never that hot. The last couple of years have been different, and this year has been unbearable.

    So — I have a 2800 sq. ft. 2.5 level house with 10 inch ducts. It’s set up for multi-zone with 3 ducts originating at the furnace: one for each level.

    I’ve had a couple of contractors come in and look at my setup, and all have agreed that the ducts are undersized for a 5 ton systems (no one has actually done the calculations yet). The last contractor was the one who suggested the mini-split setup for my house.

    I understand the concept and benefit, bit going down this route scares me a bit between pulling 240 across the house to the intrusive panels.

    I am wondering if you had any thoughts? Even with the increased heat we’re seeing in the area, I don’t expect excessive AC usage, so efficiency is not my #1 priority. However, I do need to get the house cooled about 15-20 degrees as we’ve broken 90 degrees inside the home a few days.


    • Hi Ted – Here are a few thoughts on your situation. First of all, if the only problem you have is the sizing of existing ductwork there are some ways this can be addressed (e.g. by adding additional flexible delivery ducts, etc.,). However, there might be other problems with your system which might be keeping it from keeping up with your cooling demands on the hottest days and there are certain load calculations (ACCA manual J) and duct calculations (ACCA manual D) which could probably help a lot in determining the root cause of your HVAC problem. Here is the link to the industry group (ACCA) site which we support. This site should provide information about both these calculations and also has a contractor locator app. https://www.acca.org/home

      If your existing system if newer and running properly (perhaps with improved ducting) but is just not large enough (BTU/hr) to properly match your increased load you could try “adding” one or more ductless mini-splits to some critical areas of your home to deal with the under-capacity of your central AC system. This would also give you the benefit of zoning (and maybe heating if you get a heat pump) in those. However, if your system is older you might be better off just replacing it and getting it all sized right. Our recent survey shows that AC systems are usually replaced after about 14-16 years (or more depending on usage) so that might give you an idea about how much longer your old system will run.

      In any case, we recommend getting 2-3 estimates from qualified contractors to troubleshoot your system and make recommendations – and this should include doing the load and duct calculations. I hope this answers your question. Good luck with your HVAC project!

    • Hi Abe – NYC is definitely in a colder region that requires significant heat during the winter. Boiler heat is a “whole home” heating solution and probably serves multiple individual room, hydronic radiators in your home so you would need to match the total heating capacity (BTU/Hr) provided by your boiler to all the radiators if you were going to totally replace the boiler. So, you would probably need multiple mini-split heat pump units, each with their own indoor unit matching each radiator heat capacity to totally replace your boiler. Rather than replacing old boiler heat systems, some people retain it and add mini-split heat pumps only in certain rooms within the home to provide AC to those spaces in the summer and to provide some additional heating benefits in the fall and spring when it is cool but not cold. Most heat pump systems are not very efficient with delivering hot air when temperatures get below 15F so, depending on which system you used, on the coldest days you would probably spend less energy and be more comfortable with your boiler, especially if cost of natural gas and fuel oil remains low. Heat pumps can be very efficient when the outdoor ambient is above 40 degrees but when it is really cold outside there is just not enough heat energy in the outdoor air to move inside to keep the space warm. The result is that your heat pump will probably run on less efficient, back up auxiliary resistance heaters (if available with the heat pump indoor unit). In any case, we recommend getting two or three estimates from different contractors to make sure your heat pump additions or replacements are sized properly for both your heating and cooling needs throughout the year. I hope this helps to answer your question. Thanks for visiting our site!

  103. My husband and I had a Mitsubishi MSZ-Fh15NA installed on August 21, 2015. The unit makes a clicking type noise every 1-3 minutes. We had the installer come in and he sprayed dry lubricate in the unit but the clicking noise continues. He said Mitsubishi says this noise is normal. He states it’s the heat/cool expansion. I have several friends with ductless heat/cool units they do NOT have the clicking going on and never did hear any noise. Installer said the noise should stop in 6 months. REALLY????? The clicking is quite annoying. I bought it due to the marketing of being so quiet. NOT MY UNIT, I like the heat but the noise is drying me crazy. Any suggestions?

  104. I had a mini-split installed into out master bedroom two weeks ago. I have never slept so comfortable. Living in South Florida can be very uncomfortable without proper a/c. We moved into a new home and had this installed. As I sit here, they are installing a second in my adult sons room. We love it. Had both installed for a total of $3,000

  105. Interesting article. thanks for sharing! I live north of Seattle (edmonds) and I have a ranch/rambler house that is 1500 sqft and has no ducts. We have electric baseboards everywhere and our electric bill is painful in winter over $300 a month but only $50 in summer with celling fans. I have a gas hook up but putting in ducts can cost $4-5000 and a gas furnace and install doubles that so 10k. Do you think a single 24k mini split 2 ton unit would be enough to warm the house cheaply even when it is around 32F outside or would I just end up using the electric baseboard heaters and high electricity bills? Thanks in advance for any insight you can provide!

    • Hi John. Here are a few things to consider. From your comment it sounds like energy used for heating is the primary challenge with your situation. Adding a heat pump mini-split unit should improve your cost of operation relative to baseboard electric heaters for the ambient temperatures above about 15-20F (well below your 32F question). Heat pumps work really well when it is cool but not really cold – likely in your area for most of the season. When it is really cold outside, there is not enough energy in the outdoor air to pump into your home and the unit will switch over to auxiliary heat anyway which would be similar efficiency to your baseboard heaters. We usually recommend “adding” units like this to the heaters you already have for at least one or two seasons to make sure you are ok without them and also to use as a backup system. To your question about sizing the system for your space it would be best to have a qualified HVAC contractor do those calculations which account for such things as windows, insulation, air leaks, etc to get the right capacity. One other point we try to make in these situations is that adding a new, higher efficiency system will not reduce your energy bill if you run it more than your old system. If you have a particularly cold winter and you keep the temperature warmer than you did with your old system your actual energy bill might be higher. Better efficiency only yields lower energy costs when you run it in a comparable manner. Also, we recommend getting 2-3 estimates from local contractors before deciding. Good luck with your HVAC project!

  106. Does anyone know if there is a mini-split that has a fan that will go off from time to time? Like a regular AC system? We are being driven crazy by the continuous fan noise of the unit we installed.

    We have a unique small house and a mini-split fits our needs here in FL. But noise unbearable. Especially for me as I can hear the high-pitched hum. Sometimes we think the system is defective.

  107. We live in Thousand Oaks, California, in a 1,400 square foot house built in 1963 with electric baseboard heat and no ductwork/air conditioning. We only get too hot and/or too cold about 10-20 days per year. Is it worth it to install an air conditioning system? Window units are not an option due to the shape, type, and locations of the windows. We have ceiling fans in all of the rooms. And our portable unit on wheels can’t be used in the bedrooms due to their small size and windows being too high up for the exhaust ductwork, and we’re not that interested in cutting into the stucco/wallboard. Any suggestions?

    • Hi Lori – for 10 to 20 days out of the year, in Southern CA you may not want to go deal with the expense and construction issues associated with a whole-home HVAC solution. You could try having a contractor install a small ductless mini-split, heat pump system in one room (probably a bedroom?) that gives you the most discomfort on the extreme days and see how you like it. This system coulod augment your baseboard heat in the winter and give you some cooling in the summer. If you like it you could add more later. You should probalby get a couple quotes from different contractors and make sure the one you choose understands your situation and what you are trying to accomplish so it can be sized properly for your space.These units will use an indoor evaporator that hangs on your interior wall and requires a hole to be made to get the tubing and wires to the outdoor unit so you should ask the contractor how it will look etc – both inside and outside, after it is installed. Hope this helps. Good luck with your project!

  108. I respect that the author has done some research, but there are some glaring problems with some of this information. First, ductwork is rarely if ever run inside the conditioned space. Second, all split (ductless or central) systems have at least some of the lineset run outside of the conditioned space, with most having ALL of it run outside the conditioned space. This is more or less a non-issue though since the heating or cooling loss from an insulated refrigerant line is fairly negligible. Third, the costs associated with installation simply cannot be summarized like that. 2 houses with 2k sqft space could have vastly different requirements for a ducted system.

    • Hi Amedaius. I totally agree with your suggestion that replacement installation costs (for both ducted and ductless systems) are often difficult to estimate without actually being on the job, doing the load calculations and figuring out clever ways to configure the system(s) in an existing space. This is why we usually suggest getting 2-3 quotes from a few different, qualified contractors before deciding on both the equipment and the contractor doing the installation.

      Also, your points about internal and external ductwork and line sets were addressed somewhat in the DOE study mentioned above. I am not sure about frequency of exposed ductwork within the installed base so we probably need to do some more research on that at some point. Thanks for your comments!

  109. There’s a lot of different opinions and hype about these systems and the bottom line is they are very good for what they were designed for, but not necessarily every application. I have seen these is use overseas and thought they were pretty neat long before I ever saw the first ones introduced here the USA. Keep in mind that in Europe there is a lot of urban living (apartments) and smaller homes than here. Much of the older construction there utilized steam radiator heating or electric and no ducted heat or A/C that we commonly see here. A/C was very rare even in Southern Europe (Spain & Italy). These units were ideal adaptations for over there as you could mount the compressor unit to the outside wall even several stories up, and mount the rest the ventilation unit on an inside wall.
    They were never meant to replace your home A/C compressor type unit set up to use the heating ducts in your home. Also great to use in small cabins which is why I’m shopping for one. When I was deployed, our CHU’s in Iraq and A’stan utilized these type units and kept everything heated and cooled quite comfortably. Basically, if you have ducts use them – much more efficient and economical even if you have to replace the compressor unit outside. If you don’t or have smaller spaces to heat/cool, additions, shops, cabins, etc. – it’s not a bad way to go and they work very well. Your choice, I just thought I’d add my two cents…

  110. I’m thinking about replacing my 30 year old unit for a mitsubishi ductless system. I”m remodeling my home and I’m moving the unit to a different place in the house and it would be more expensive with a traditional ducted unit. But I live in souther Louisiana and I’m concern with humidity. Can you elaborate more on this issue.

    • All AC units dehumidify just due to how they work. The air passes over 40 degree evap coils, which draws out moisture that is above that dewpoint. Now, some newer AC units also have a dehumidistat to control humidity beyond that, but it is pretty unnecessary. Both central and ductless AC will dehumidify, and the condensate will have to be piped somewhere (some systems pipe it directly to the drain line of your house, and some people opt to pipe it into their water collection system for landscaping).

    • Hi Arturo – There have been concerns posted by visitors to this site about humidity control and these seem to be mostly related to the use of multiple units or units with multiple indoor evaporators, being applied in fairly large spaces. This may be related to managing airflow among the various “zones” assigned to the evaporators as documented in a recent DOE study – link below.
      In highly humid areas, the energy required to remove humidity can often be greater than that required to maintain temperatures and the key to removing humidity is to insure there is adequate airflow across the cold coil for long periods of time. As an air conditioner runs, the moist air hits the cold indoor coil, condenses on the coil and drips into a drain pan and is then piped outside of the conditioned space. If something happens that reduces the amount of air moving across the coil(s) then you might not have enough humidity removal. For example, if the system is oversized (too many tons, or BTU/Hr) for your space then it may not have enough run time to remove all the humidity. If your mini-split zones are too far apart and there is not good airflow sharing among the units you might also experience humidity spikes in some areas (zones) or at the interface of these zones. Another problem that visitors have posted deals with the moisture (condensate) removal. Each indoor unit (evaporator) will have a tube that drains the moisture outside the space. If these become clogged, the moisture will drip down, out of the bottom of the indoor evaporator and into your living space and the amount of water that will drip out can be significant at times. You could have the same drainage problem with a ducted system but these usually only have one drain and are often in the basement. If you go with mini-splits make sure you ask your contractor about how to maintain these drain lines.
      On this site, we usually recommend getting 2-3 estimates for both ducted and ductless options, from different contractors in your area before deciding. Moving the indoor or outdoor unit or having them relocated in a new area may not be as expensive as you are thinking but you will not know until you get a few different quotes. Some contractors are better at this than others so it makes sense to get a few different opinions.

  111. When they come out with a fan/coil unit that sits near the floor, under a window for example instead of up near the ceiling, acceptance will grow. The units hanging on the wall near the ceiling have a retrofit look.

    • Hi Ron – Thanks for your post. One other recent post indicated that the reason they like to place those units high on a wall or in a ceiling is so the cold, supply air falls and the warn air in the room rises to cool the whole room. I guess that is what you were suggesting but I was not sure.

  112. I have a cement block house that was built in 1956. It has a minimum amount of wall insulation that I can’t do much about and windows that I am in the process of replacing as I can afford it. My biggest problem is that I have radiant ceiling heat that only works in spots. I can’t afford any more 700+ dollar winter electric bills and 300+ summer bills. I’ve had the contractors out for estimates and have settled on the one I want to do the work. My question is the estimate between a variable speed heat pump with a variable speed air handler with rigid fiberglass duct system and all the other standard equipment and the estimate for a mini split system capable of do the same job is within 100 dollars of each other. They each have pros and cons for my needs and because of the reading and research I have done I am leaning towards the mini split. What I’m wondering is which system in anyone’s opinion will reduce my electric costs and heat and cool this thing I call home. I am disabled so lowering my astronomical electric bill is very important to me. Just so you know my house is only 1000+/- sq. ft. thanks for any opinions anyone can give me, Randy.

    • Hi Randy – From your post I can tell that you must live in a climate that has full heating and cooling seasons and thus might also have periods of high humidity. Electric radiant heat is usually not very efficient or cost effective so you should realize some savings from going away from that as your primary heating source. It is not clear what air conditioning system you have now but if you have window/room AC you should also realize some improvement in both energy efficiency and comfort with either ducted or ductless systems.

      One thing you might want to consider is how much capacity you have for both heating and cooling now versus what you are going to have when you install your new system. Some people install a higher efficiency system but still see an increase in energy use because they had to increase the capacity level of the new equipment (measured in BTU/Hr, Tons, etc) to match the needs. It is important to have a good contractor do the calculations to estimate what your new energy costs are going to be with various system options and sizes. The system needs to be sized right or you may not achieve good performance on extreme days and good humidity and temperature control on moderate days and most nights. Again, you might get better, more efficient cooling than your room units but if you add BTU’s you could be using more energy even though it is a more efficient system. We have seen people post about this on our site so it is probably worth considering.

      On the mini-split option, if your layout allows you to separate your home into “zones” and you can get enough indoor evaporator heads into those spaces you might be able to better manage the energy spent on conditioning those spaces (i.e. turn them off or down when not in use). You can do the same thing with a ducted system with variable capacity but you have to have the contractor set up the ductwork to do that. You might want to ask your contractor about maintaining proper air flow and filtration to various parts of the house as well. You should also try to get either the ductwork or the refrigerant lines into the conditioned space. Even though these are usually insulated, you might see energy lost if they have a lot of areas that are exposed to the outside. A comparison of ducted versus ducted systems was done by the Department of Energy a while ago so you might want to review those results before deciding.


      It also appears from your post that you are going to use a heat pump in either the mini-split or ducted format. If so, you should note that heat pumps work very efficiently until the outdoor temperature goes below a certain level (usually about 15F). Once it gets below that temperature, your heat pump will usually go to an auxiliary heating mode which involves built in resistance heaters – and thus, will be less efficient. If you live in a climate where temperature frequently gets that low for long periods, you should ask your contractor about this. Some variable speed systems have extended the operating range to below 15F outdoor ambient but not all so you probably need to ask. For ducted systems, some people also use both a gas furnace and a heat pump to achieve high efficiency across a wider range of outdoor ambient conditions and also give some flexibility to deal with the relative costs of electricity versus gas throughout the heating season. These are called “dual fuel” systems.

      The efficiency ratings for ducted systems and mini-splits are pretty much the same. SEER (Seasonal Energy Efficiency Ration) is the rating for cooling and HSPF (Heating Seasonal Performance Factor) is used for heat pump heating. If the ratings on various systems are the same and the systems are about the same size (see above) you should expect similar energy costs with either one – depending on how much you use them. Again, your contractor should be able to estimate this when the sizing calculations are done.

      You mentioned that you are planning to improve your windows in the future. You should discuss this and any other improvements (insulation, etc) and other layout changes you are planning with your contractor because these could affect the overall capacity needs for your space. With a variable capacity system it could adapt to these changes but it might still be important to discuss. There are also some high efficiency “stepped” capacity systems that might provide a lower price point option versus the fully variable system so it might be good to ask about these as well.

      I hope you find this information helpful. Good luck with your HVAC project!

  113. Thanks for creating this forum – it has been a very interesting read as I research how to address my HVAC situation…

    I own a 2,400 sq ft home in NJ built in 1970 that has central air with ductwork to all rooms. Unfortunately, the system in place does a terrible job cooling the upstairs, with temperatures about 10-15 degrees warmer than downstairs. To address this issue, we run window units at night in the 2 currently occupied bedrooms and turn up the central at night in the summer. To make matters more complicated, the upstairs bedrooms at the end of the house furthest from the furnace do not get sufficient heating in the winter, so my daughter’s room had a space heater last winter to keep her warm.

    We are expecting baby #2 in November, so we are debating how to address this situation in both bedrooms for the kids. Originally, I was considering electric baseboard in the kid’s rooms and using window units in the 3 bedrooms in the summer to supplement the less than efficient central air unit. My concerns with this solution are both efficiency as well as exposing a baby and toddler to hot baseboard units. Would a 3 unit (master and 2 bedrooms) ductless mini split system for my upstairs seem appropriate here? It would address my heating and cooling issues in one step, increase the efficiency of my current alternative, and be a safer solution for young kids. How does this compare to the upfront cost and efficiency cost of adding a second zone to my existing central for the ability to heat/cool the upstairs and downstairs separately?


    • Hi Gary. Thanks for the post. Here are a few things to consider. If you read through some of the comments to this article you probably have concluded that we recommend getting at least 3 quotes/estimates from various contractors, and to do this for both ducted and ductless solutions. Some contractors can quote both system types by the way but you might need to ask them. Each contractor might have a different approach to solving your HVAC problem so it could help you to get some different ones to look at it.
      When you have contractors over you should have them do some measurements and calculations to determine what size system you need for your whole home and also the spaces that are not being conditioned properly. Most contractors know how to do this. We support the industry group ACCA and they have a contractor locator tool. Here is the link.

      In any case it might be good to consider the age of your system before making this decision. Most systems are replaced when they are about 16 years old (national average) so if you have an older system you might not want to do an “add on” solution and then turn around and have to replace your main system if it quits working in a few years. The point is, you might be able to address all your problems with a partial or full replacement of your existing system along with some modifications to your existing ductwork to address the hot/cold spots on your second floor. However, if your existing system is not that old, then you could consider adding a second system – either central or ductless.
      A ductless, add-on system would have refrigerant lines running from the outdoor unit to each of the indoor cooling units located on the walls in each bedroom. You might be better off quoting individual, mini-split units for each bedroom and avoid all the refrigerant lines. On the other hand, if you decide to add a central, ducted, heat pump system to your second floor, you could place the air handler and ductwork in the attic (if there is room up there) and run new, additional distribution vents to each bedroom. Either approach might address both your heating and cooling needs and also give you a 2-zone set up – which is good for temperature control and energy savings. However, if you end up replacing your old system with one, new system, you might consider a 2-step, 16 SEER, high efficiency system. Having 2 steps of capacity might also help you address some of the cold/hot spots on extreme days but make sure the contractors perform the calculations to help you select the right system size.

      On the topic of energy savings, since you are “adding” a new system you could also be “adding” to your energy bill depending on how much you run it. The new systems will probably be more efficient than your old system but if you have to run both the old and the new systems to keep up, you will probably be using more energy unless you can significantly reduce the runtime on your existing system. If you replace your old system with a new, high efficiency, two –step system you might be able to reduce your overall energy bill. The contractors quoting new systems should be able to estimate this and also advise you about any local rebates available in your area.

      I would like to make one other point about both ductless and ducted add-on systems for your second floor bedrooms. In either case you will be getting a new source for AC in the summer. However, to get additional heating in the winter you will need to get a heat pump model. Heat pumps are sort of like AC units that can run in reverse in the winter to move heat from the outdoor air and into your space. The problem with these systems is that they are not very efficient at very low temperatures (e.g. below 15F). However, since you might be keeping your existing furnace, the combination of that heat source with the auxiliary heaters built into the heat pump should help you keep up on the colder days and nights. These heat pumps would also not have the exposed resistance heaters you mentioned.

      Again, take the time to get a few different estimates from good contractors for both ducted and ductless. Good luck with your HVAC project and thanks for posting on our site!

  114. Does anyone have an idea about the total cost might be for the ductless ac unit and installation? I’m hoping it can be done for under $3,000 for a 850 sq ft space.
    Could online calculation services somehow be useful to plan my budget ahead? like this:
    Thank you in advance!

    • Hi Julia. On this site, we recommend getting at least 3 estimates from qulaified contractors for both ducted and ductless options before deciding. Prices and installation costs ofen vary greatly for various reasons. Also, make sure the contractor does some measurements and inspections to make sure the equipment is the proper size for your space. Good luck with your HVAC project!

  115. This is a great textbook application for a mini split system. REMEMBER a “Ducted” system is a “Central Vacuum System” for your home, it sucks all the contaminates from your whole house, and uniformly re-distributes them EVERYWHERE !

    This includes areas they were not previously. Why would you have to clean ducts ? As well older ducts/ducts NOT designed for ac can be improperly insulated, this = condensation. Condensation = MOLD !

    They can and will drip water into the insulation in your walls and attic/floor space. Water dripping on drywall backing = BLACK MOLD !

    For someone concerned about allergies, I’d watch this one !

    Far cleaner is a ductless system, the issue would be if the “HOA” will allow placement of “ANY” not just mini split, ac compressors on the property, outside your unit ? I believe as you would be on the ground floor, this offers you much more options, and maybe you could hide them in the bushes, so to speak.

    The reason I oppose one compressor, multi head mini split systems is simple, EFFICANCY.

    Example you are installing ac in two bedrooms, one is a guest room, you don’t use. The other the master. You are told each requires 1.5 tons of cooling, 2 x 1.5 = 3. Ok so you now need a 3 ton rated compressor. You are paying to run a 3 ton compressor when you only require 1.5 tons of capacity. Do you see an issue here ? I do !

    As well the x-tra valves, controls and parts are trouble prone, and added maint. down the road.

    I agree replace the furnace with a new high efficiency unit AND add a HEPPA and whole house electrostatic, electronic filter at the same time. I would NOT add the central ac.

    Another issue to check, and it sounds like you may have it now, have the new place as well check for it, “DUCTBOARD” this is a toxic nightmare from , to say the least.

    It is on the outside shiny aluminum foil skin bonded over a nylon netting which is covering a sheet of fiberglass batting, bonded with deadly chemicals mainly formaldehydes ! Inside the “Ductboard” the air is at great velocity in 100% contact with this bare, raw chemical laden fiberglass.

    For the life of the system it leaches fiberglass shards, fiberglass dust and formaldehyde vapors into your living space. I have personally been into attics and seen these ducts where 100% of the fiberglass was gone inside the duct, and only the foil was left flapping in the wind.

    This happens at high velocity areas inside the duct for example where the transition is from the HVAC system outlet to the “DUCBOARD” system and at 90 degree bends.

    These systems as well, as in essence your duct is lined with “Shag Carpeting” attract all sorts of dirt, dust, debris and can not be cleaned.

    What happened to all that fiberglass and formaldehyde, that is now gone from inside the ducts ? It is now in the lungs of the building occupants, because remember the air IS filtered going into the system, it IS NOT filtered going out of the system !

    It is my understanding the installation of systems using this product, are now banned or no longer allowed (?) BUT ! there are still thousands of miles of this stuff in use today in older 80’s constructions, BEWARE !

    As well regardless of the type of ac system you select, go with the highest SEER you can find, this means a “inverter Compressor” system.

    On the mini split ac, for a few bucks more you can add “Reverse Cycle” (This is what nearly all motels have today, that have ac/heating in one unit usually under the outside widow of your room)

    It WILL save you money is you only need heat in say the living room on a lazy Sunday at home, and the bedroom at night, vs running the furnace, sized to heat the whole house, regardless of the fuel source(s)

    As I said prior, I own 5 Mini-Splits. They are 3) 1.5 ton and 2) 2. ton rated units. Here now it is in the upper 90’s F and 80% RH the two ton units are pulling ONLY 2.2 amps each !!! The 1.5 tons, ONLY 2.0 amps each !

    Do the math here folks that’s 10.4 amps TOTAL for all 5 units, your “Whole house” ac well I can tell you friends, it’s drawing from 28 to 50 amps right now !

    It’s your money ! Dirk


    • Thanks again for your post, Dirk. These are very interesting points.

      I am sure all ductwork and installations are not the same but I installed some fiberglass duct board type ducts in my home about 20 years ago and they are still working fine. I was looking just last night at the supply vents and they are still very clean with no accumulations of dust or dirt or anything. On the other hand, I had a pretty good contractor install the system and I also bought a premium air filter. Also, it looks like duct board products are still in use today as I checked an industry association web site – http://www.naima.org/insulation-knowledge-base/duct-hvac-insulation/types-of-fiber-glass-duct-insulations.html

      I will continue to watch this issue and might need to do some more research on it. Please check back with the site in a few weeks. If I find anything new on this topic it will appear as a new article so you might need to search for it.

  116. Hi,
    I am new to this forum & have found it very informative. I am considering buying a 1200 sq. foot condo in Southern California. The condo has 2 bedrooms & a kitchen + great room. It is on the first floor of a 3 floor building. The condo was built in the mid-80s. It has heating supplied by a central furnace. There is no air conditioning. Both my spouse & I have severe allergies. At our present condo, we had a company out to clean the ducts and were told that the material used to make the ducts could not be cleaned without tearing. Before we make an offer, I am having an air conditioning contractor look at the system & advise us as to the feasibility of utilizing the existing ductwork to install air conditioning. We are going to be repainting the condo, so if we have to install new ductwork, this would be a good time to do it.I want to know if the furnace looks like it needs to be replaced. Finally, I want estimates as to the costs of both going with the duct system & a duct less system. Are there any other questions I should ask the contractor. Any advice would be greatly appreciated.

    • Hi Gail – I think you are on the right path to making a good decision. I would encourage you to get 2-3 quotes for both ducted and ductless options and for the ducted option – and also get itemized estimates and the contractors’ opinions about the need to replace the existing ductwork. It will take some time and effort but it will be worth it. Prices vary from region to region and from one contractor to the next and it pays to shop these purchases since on average, people in the US spend between $8,000 to $10,000 for a new or replacement HVAC system – and more if you go with a premium system.
      Here are a few other things you might want to consider and discuss with the contractors. By the way, our recent research indicates that finding a contractor you are comfortable with will be very important, irrespective of the type of system you choose. Here is a link.


      First of all, on the need to replace your furnace, the national average age at replacement for HVAC systems is about 16 years but run-time is more important than years. So, if your furnace/heating system in Southern California is the original system, it might be twice the national replacement average age but if it did not get much run time during those years and was well maintained it could still be ok. You can ask your contractor about this after he inspects it.

      One of the things you mentioned is your allergies. The tradeoffs with ducted versus ducted systems on this topic tend to vary from region to region and the individuals involved. If you have very bad ductwork that has lots of leaks and has accumulated a lot of allergens then it might be a good idea to replace it or go with ductless. However, if you go with a ductless AC only system, you will still be using your ducted furnace during the heating season. Leaving ductwork off for a whole cooling season and then turning it on during the heating season could be causing some dust/allergy problems – especially on start up. One of the benefits of a central, ducted system is better whole home air circulation through a fairly large filter built into the ductwork. When you discuss your ductwork, also discuss the various types of air filters you can purchase – they have all kinds. If your ductwork is not too bad, you might be able to just add a very good air filtration system to address some of your allergy challenges. In contrast, the ductless systems tend to have smaller air filters and they only circulate air in one space – usually a room at a time. The air delivery and the return are all in the unit that hangs on your wall or in your ceiling. So, while you don’t have ductwork, you also may not have good airflow and air filtration throughout your home. This becomes really important in places where there is high humidity due to the potential for mold. This may not be an issue in your CA ocation but it is something to consider and to discuss with your contractors.

      Another topic you should discuss is energy costs. Both ducted and ductless systems come in various efficiency ratings so you should be aware of this. The AC rating is called SEER (Seasonal Energy Efficiency Ratio) and the same rating is used for both ducted and ductless systems. One energy-saving advantage of ductless is that you can zone off sections of your space by just not running the system in those spaces or by adjusting the temperature so it does not run as much. If you feel like you can zone off rooms and spaces in your condo this might be something to consider. You can also zone off a ducted system by simply adjusting the vents for more or less air flow and there are even some automated systems that allow you do this remotely. However, if you plan to zone off and shut down a big part of your space with a central system you should go with a 16+ SEER system with at least two steps of capacity modulation. This will allow the system to adjust down the cooling required for a significantly smaller space. If you have too much cooling capacity, the system will not run long enough during cycles to get proper airflow. The variable capacity central AC systems also provide better temperature control and are less noisy than fixed capacity (13-14 SEER) systems. Your contractors should advise you on expected energy costs and comfort benefits of the systems quoted and the various SEER levels for each.

      One other suggestion would be to consider a “heat pump” in either your ducted or ductless options. Heat pumps are air conditioning systems that sort of run in reverse during the heating season. These heat pumps can be a very energy efficient way to heat your home when the temperature is not lower than about 15 to 20F. Since it does not get that cold in your area you might be able to use a heat pump to heat for the whole heating season. Some people add heat pump air conditioning systems to their existing (older) gas furnace systems to allow switching back and forth from electric to gas based on the relative rates during the season. Heat pumps are a little more expensive than straight AC only systems but the energy savings you get with a heat pump could pay that back over a few seasons depending on how you use it. You might talk to your contractors about this heat pump option.

      We also encourage people to discuss proper sizing (capacity, BTU/Hr) for any new systems because if the capacity you install is too much or too little for your space and the amount of insulation, sunlight, etc you might have problems. For the size of your home, if you go with mini-splits you will probably need more than one or two systems and each system might need more than one indoor evaporator cooling unit. Some people on this site have referenced some concerns with these “multi-evap” ductless systems which have one outdoor unit that drives multiple indoor evaporators on the walls or ceilings in your home. I am not sure exactly what the concerns were but it could be related to the long refrigerant lines used to send cool gas to the indoor units but I am not sure. You might ask your contractors about the potential problems of having these long refrigerant lines and how they are going to install and insulate them. Also, ask them about the condensate (moisture) lines that run from each indoor unit to drain outside and how often these need to be cleaned or serviced.

      Also, since you are in condominium facility you should probably check with your association and local regs to see if there are any restrictions on types of air conditioners you can install. If you go with mini-splits you should also talk to your contractors about how these will look on the interior and exterior of your building. I hope this helps you with your HVAC project!

  117. After reading this post on the “Myths” I found it very biased, a mini split ac system is the only way to go. As Americans living fulltime in Mexico, we own 5, from 1.5 to 2 ton. They are all inverter units.

    The comfort offered is far superior to ANY central system, as well you have individual control over each and every room. Statements like most are not ready for mini splits ?????

    Bedrooms are a very good example, you can of course cool it as you like, without running a whole house system. Ductless mini splits ARE far more efficient than any central system, offering far more comfort.

    Efficiency IS NOT leaking ducts, but it is, running a compressor sized to chill a barn, vs one or two mini splits cooling the rooms you need cooled, = massive savings ! AND more comfort.

    As to cost, I agree that these units are FAR more expensive in the USA vs Mexico and South America, like 3 to 4 times. As in Mexico for example MOST appliances and electronics are double (or more) US prices, a 1.5 ton mini split system new in the box can be had for about 4-500 USD ! Add about USD 200 for inverter.

    They are very easy to install, but the one downside to the American Market would be the fact each unit has it’s own compressor that must be mounted close to the placement of the unit on the wall in the home. This means if you cool 5 rooms you will have 5 compressors scattered around your home.

    One more comment as to comfort, ac chilled air MUST enter the cooled area at the CEILING ! not the floor as most residential systems do. Cooled air is very dense and drops like a rock, blowing it through floor vents designed for heat, then returning it through a floor return, designed to return cooled air for heating is not efficient nor comfort.

    A mini split system delivers the cooled air AT THE CEILING where it belongs, it ALSO picks up the air to be cooled AT THE CEILING, OK where is the hottest air in any room, HELLO the ceiling !

    Central ducted residential ac systems ALL have significant stratification layers of hot and cooled air, this is totally eliminated with a ductless mini split system. Want the “ULTIMATE” in ac comfort, it ain’t a ducted system for sure.

    HOWEVER if considering a ductless ac system and your contractor wants to save you money by pushing a multi head system with one compressor operating 2 or more head units, run like ! Do not fall for or purchase one of these, you will forfeit any efficiency gains, add more valves/solenoids = more trouble, you are back to running a compressor designed to chill your whole house once more vs one room where ductless systems really shine !

    A ductless system can be installed and up in running in one to two hours !

    • Thanks for your post, Dirk. I appreciate your comments, especially those related to situations where room by room zoning is a priority. Your insight about the placement of the indoor units near the ceiling will be helpful to other visitors to this site who have been having problems with poor air circulation. I also noticed your comments about “mulit-head” or “mulit-evap” systems. We have seen this problem come up from time to time in both comments on this site and also in the DOE testing reports.

      I am hoping to provide a sumamry and a recap of all the posts on this topic over the next few weeks so you might want to check back then if you are interested. Thanks again for your post.

  118. Hi Frank,
    I live in Michigan and am looking at buying a 1300 square foot home with a cement “Michigan” basement. It currently has electric baseboard heat and window air conditioners. I’m looking to retrofit a/c and more efficient heating, but am very confused on which options are best price and quality for both installation and long-term use.

    • Hi Deborah – Considering the size of your home and the fact that it is in Michigan you can probably consider a few different options for both heating and cooling but your most critical need will probably be for heating. You could start by getting quotes from local contractors for a central ducted gas furnace with an air conditioner as part of the package. It should be relatively inexpensive to run ductwork across the ceiling of the unfinished part of your basement to hit all the rooms on the first floor and maybe run deliveries to the second floor through the walls. Some people in your area have also been buying a “heat pump” style air conditioner to go along with the gas furnace. This combination can be an efficient way to use the heat pump to heat your home on days and nights when the temperature is above about 15-20F. When it gets below that range you can switch to the gas furnace. Another consideration might be to buy a high efficiency system which could offer both lower energy costs and improved comfort. In any case, the new equipment you buy could, (and probably will) reduce your energy costs relative to your current equipment, depending on various factors. Your contractor can probably give you energy savings estimates for this along with the quotes you get from them.

      You could also have a few contractors quote ductless mini-splits (subject of this artcle) but the heating function on these units are also “heat pumps” so when the outdoor temperature gets really cold they will probably be running on their internal, electric resistance heaters so these may not be very efficient and/or might have trouble keeping up with the cold Michigan winters. If you decide to go this route I would recommend keeping your baseboard electric heaters for at least one heating season to make sure your heating needs can be met by your new system.
      We usually recommend getting at least three quotes for each style of system before deciding. The contractor should also make sure the system is sized properly for your home and the amount of insulation you have, the R-value of the windows, etc. Our recent research suggests that having a good contractor is a very important part of your overall satisfaction with your new system so you should plan to take some time on finding the right ones – see the links below.

      There are many other articles on this searchable site which could answer other questions you might have about terms like “heat pump” and “mini’splits”, etc. I hope this helps. Good luck with your HVAC project!



  119. Hi there, I am very new to this forum. I live in a row home in Philadelphia which has radiator heat. We use a large in the wall air conditioner unit for our downstairs living room space and 3 separate units in the windows for the bedrooms. Would it be more efficient for us to have a Duct A/C unit installed or these mini units everyone is talking about. The large unit cools most of the down stairs except for the kitchen when I am cooking & the bathroom is like a sauna. I would appreciate any feedback you could give me. Thanks

    • Hi Janet –

      In general, people who move from window/room AC to ductless mini-splits will realize both increased energy efficiency and improved comfort. To the extent that you can locate the mini-split indoor wall units to get proper cool air flow into the various rooms you might also be able to address the cold/hot spots you mentioned. However, you can also realize many of those same benefits (and maybe others) with a ducted system – but since you have no existing ductwork it might be difficult or expensive to have a central ducted system installed. What we recommend on this site is to have at least three qualified HVAC contractors quote your job as both a ducted job and a ductless job to compare prices and also to allow you to select a contractor you are comfortable with.

      A few other points to consider would be doing this job in phases or as a hybrid approach, using both ducted and ductless combinations. For example, talk to the contractors about addressing certain problem areas first – maybe get a ducted or ductless solution for the upstairs space and/or a small mini-split for your bathroom “sauna” and that surrounding area. Since you already have radiator heat you should also ask them about the benefits of installing a (ducted or ductless) heat pump (does both heating and cooling) to use on more moderately cold days in the fall and spring seasons instead of your boiler. You might have to talk to a few different contractors to find one that is on the same page with your particular HVAC situation and how to resolve it. So, plan on this taking some time and effort to figure it all out.

      One other point, no matter what type of system you decide to go with (ducted or ductless), make sure it is sized properly for your space. The contractor should look at the size of your space, the amount of insulation, the type of windows, etc before determining the size of system(s) you will need. Proper sizing and installation are critical to both the energy efficiency and comfort you get from your HVAC system.

      I think it might be worth reading through some of the other posts on this article and one other similar article (link below) to see other opinions and suggestions. I hope you find this information helpful. Good luck with your HVAC project!


  120. Thanks for the helpful blog and forum – lots of useful information here. We decided to convert our garage into living space recently so needed to decide on an HVAC system. I am a general contractor so I have been involved with the placement of various types of HVAC equipment in lots of homes. I figured that a ductless mini-split heat pump would be the easiest and cheapest to use but all the quotes that came in for mini-splits were about the same as the ones I got for adding a small central AC/heat pump system with the air handler and ducts in the rafters above the space. The ducted system was actually cheaper than the ductless after all said and done… $4600 for the ducted system and $6k+ for the ductless.

    We did not have a lot of space to mount the wall units anyway and running condensate lines in the ceiling was difficult to due to the space available. It gets humid here in the summer and I had heard a lot about mini-splits not dealing well with that so I went with the conventional HVAC and have been happy with it – good air flow and no issues with humidity. Also, visually it looks a lot nicer than having the ductless unit on the wall and this is probably better for resale… since it looks cleaner and more like what people are used to having in their homes.

    We set the air handler at the end of the attic space and ran insulated round, hard air supplies around the outside edge of the attic to maximize storage space and also to maximize filtered air flow from the air handler. Also, with mini-splits, each ductless unit has its own condensate drain line to run outside, so with just one central air handler we only have to worry about one of them getting clogged up over time and spilling over. We installed a pan with a drain tube and pan switch that sends a message to the thermostat to turn off if there is any blockage in the drain tube.

  121. I am a novice ! I have a small studio under 500 sq. ft. An open studio with 14 ft ceilings there will not be enough for attic ducts for heat/ac which unit of the ductless kind is the best to provide heat and ac? Are,there showrooms in LA area? Thank you

    • Hi Kelcey – A ductless mini-split should work well in that space which, I guess is in the LA geographic area. We recommend getting quotes from a couple different contractors and brands before you decide. I would also ask them to make sure your unit is sized properly for your space and also ask them about adding ceiing fans to help with air flow. You can usually find local HVAC contractors with an internet search and then schedule an apppointment to get an estimate. Our charter does not allow us to recommend specific equipment brands or service providers. Good luck with your HVAC project!

  122. Nothing at ALL suspicious or biased about this bit of advertising. Why on earth would anyone put any kind of faith in anything this bit of trip has to say about ductless heating and air conditioning systems? The guys at companies such as Emerson, the ones who make the lion’s share of their income from repairing, replacing, and supporting those big units in your basement, have a vested interest in keeping that market flowing.

    Sort of like the tankless water heater. I’ve heard so many arguments against that, too. But… do you REALLY want to waste your money on re-heating the same tank of water over and over again? And then, if your tank isn’t big enough? You run out half way through your shower because you forgot you had already turned on the dishwasher, and the washing machine was running, too! But a few point of demand (POD) water heaters and you not only have to worry about that problem, but you can get rid of that big rusty tank in your basement.

    So, too, with the ductless heating systems. Why would you want to keep heating/cooling that spare bedroom or the downstairs/upstairs/back room if they are not being used at the moment? If you are at home alone, in your bedroom at night, do you really want to be cooling the whole house? Why? It doesn’t make sense. Ahh! But, to get ductless systems would make no dollars for companies like Emerson.

    So, again, I am moved to ask: Why would anyone put any credence in anything such a company might say about a competitor?

    • Thanks, Reese. I wrote the original article in July 2013 in response to a number of industry comments and editorials on this topic. The intention was to bring some balance back to the discussions going on at that time. We also hope to publish an update to the original article in the near future.
      In situations where a homeowner is considering both types, we usually point out the pros and cons of both and also recommend getting quotes from multiple contractors for both types before deciding. We have also provided links to a Department of Energy study to answer specific questions and address claims about comparisons of ducted versus ductless systems (shown below).
      By the way, I agree with your points about room-by-room zoning, as this is a real benefit to ductless in situations where room zoning is a priority.

  123. Frank,

    I am in the process of designing an 1.100 square foot, single level craftsman cottage in Bend, Oregon (cold winters, hot (dry but not humid) summers, and I’m interested in your thoughts on whether I should have my house designed for a ducted HVAC system or ductless mini-splits. The small house design includes 2 bedrooms (with high vaulted ceilings), 2 bathrooms, and a combined living room/dining/kitchen area with high vaulted ceilings. Overall, there is a lot of openness between the rooms and not much of a need for zone control. However, a similar house (size and design) was recently built by a spec builder in Bend and he installed a single air exchange mitsubishi unit in the open living/dining/kitchen area (this single air exchange was the only unit installed in the house).

    It seems like the house that I am designing fits the bill for a traditional ducted system, but having seen a similar house design with the single air exchange mitsubishi unit, I’m now confused as to which route makes the most sense.

    Given the open nature of the house, its small size (1,100 sf), and the area where this house is being built (Bend, Oregon), which system would be more cost efficient and effective?

    And if ducted is the way to go, given that this house has high ceilings without much space above them for the ducts, would the ducts need to be installed in the crawlspace?

    Thanks so much in advance for your thoughts!


    • Hi Angela – Given the size of your home and the climate there in Oregon, I think you could go with either a ducted central system or a ductless min-split as long as the system was sized properly by a good contractor. We usually recommend getting quotes for both ducted and ductless systems in these cases, and from at least two or three contractors before deciding because the equipment prices and installation labor charges can vary greatly for each. A few other things to consider are: if the mini-split (or any heat pump) is going to be your only source of heat in the winter and the temperatures frequently go below about 20F you might want to compare the energy costs associated with various types of heating systems as well as cooling. Heat pumps tend to be costly to operate when the ambient is very low (you can see other articles on this site which explain why this is). The heat pump decision might also depend on the relative prices for electricity versus natural gas in your area.
      Most people who use mini-splits also really like the zoning benefits which you don’t seem to need. Conversely, you have a pretty wide open space and this sometimes presents a challenge for mini-splits. These ductless systems often provide adequate, conditioned air flow to the room where the unit is located but the spaces far away from the units are less well supplied (for both heating and cooling) but ceiling and other fans could help with this.
      Improved air filtration is another benefit you might get with a ducted system as the air is circulated throughout the home and through a fairly large filter as it operates. This could help with dust, pollen and other potential allergens depending on the type of air filter you select. Running ductwork in a crawlspace or in an attic space is pretty common. You should also probably compare the warranty programs and expected useful life assumptions for any system you purchase as well. If you are concerned about the impact to future resale value you might check with some local realtors to see if people in your area have a preference for mini-splits versus traditional ducted central HVAC systems.
      Here is link to a DOE study which provides more details on the topic of ducted versus ductless.


      I hope this helps to answer some of your questions. Good luck with your HVAC project!

  124. I live in a single story 25 year old 4 bedroom 2064 sq ft house with the original gas forced central air furnace and Mastercool evaporative cooler. We have low humidity in Albuquerque. The ceilings are vaulted in every room (max is 19 feet), and the living room, dining room, TV room, kitchen, and breakfast area are all common space. The ducts are in a crawl space below the roof, where it gets so hot in the summer it has melted cable TV insulation, and the ducts are so dirty stuff blows out of the vents to surfaces below. I have kept the Mastercool going 25 years myself, I can fix any problem that arises, however even when new the cooler was under capacity for the volume of the house, at best it reduces the temperature 15 to 20 degrees less than outside. Estimates for new heater/AC were $12k to $15k, not including the needed electrical upgrade which would be another $1500. My wife and I are retired and don’t like the house too cold, but my 2 adult sons like it very cold.
    I was thinking of installing a mini-split for the bedrooms so everybody in the family would be happy, and keeping the evap cooler for the rest of the house. Is it feasible to have both evap cooling for most of the house and a closed mini-split system for the bedrooms? Thanks for this informative site!

    • Hi Steve. It is possible to use mini-splits as room coolers along with your central evaporative cooler. One reason not to do this would be if you were going to have to replace the whole central heating or cooling system soon and you could address all these issues with that one project but it sounds like you have the central units under control and are confident they will last a while.

      Here are few other suggestions – have the contractor make sure the min-split units are sized right for each room with the evap unit running. They need to do some calculations to make sure these are not too big or too small. I am not sure what the airflow situation is going in and out of the two bedrooms but you might ask the contractor about that too. On the ductwork, you could also ask the contractor to quote a better in line air filter for your ductwork and maybe even get them cleaned first – there are service companies and some HVAC contrators who specialize in this. Good luck with your HVAC project and thanks for using our site!

  125. My gut feeling (usually right) the ones against ductless are apt to lose $ in their connection to the AC business. Always follow the $ trail it will always lead you to the truth, unfortunate but true.

  126. Very helpful response. I had the four ton unit replaced with a 5 ton 2 stage slit system, and had a return cut into the ceiling in the media room. The room is comfortable and the extra air is a huge benefit to the other area of the home as well. The old unit was 23 years old…it had a good run but I am glad to replace it on my terms rather than waiting for it to go out at a bad time. Thank you again for your response. I decided against the mini-split system. If I had a bran new undersized unit I may have considered it further, but since the subject unit was beyond its expected life, it seemed best to utilize the existing ductwork and add the return with a larger unit. Anyway, I’m sitting in my 70 degree media room and glad I don’t have that old unit to worry about any longer. The much cooler kitchen is also appreciated.

    For those interested, I paid $9,800 (net of rebates but tax and install included) for a York 5 ton split system (upright air handler in a utility closet) with a 12 year warranty and a 3 year service contract from a reputable dealer (locally owned company that’s been around 50+ years). I probably could have saved some money by putting more effort into it. They originally quoted me $13,500 but after some casual discussion they agreed to reduce their price to what they claimed was ther best price. AC companies are tough to negotiate with here this time of year as it is their busiest time of year by a long shot.

  127. I live in a 5300 sq.ft. one level home. One room, our media room, is where we spend most of our time. We live in Phoenix and on hot days the media room only cools to 78-80 degrees. Currently, it is cooled by a 4 ton central heat pump that also cools the kitchen, dining room, laundry room, a bathroom and the family room. The media room, which has quality insulated duct work and 4 existing 12″x4″ vents and double doors, but no return. I prefer the doors closed for noise control reasons. It is the hottest room in the house, partially because it is on the south east corner of the house with windows on the south and west side, plus three big screens and other AV equipment generates additional heat. We want to be able to get that room to 70 on a 115 degree day. Heating ability is of no concern.

    I am trying to decide whether to purchase a new heat pump and air handler and build in zones, or simply add a smaller split system in the media room which is 620 sq.ft. There is attic space. I lived throug a complete HVAC re-design in my last house (dual 5/1 ton Trains, l20i, with 5 zones) and am tempted to just address this issue with a split system. I would benefit from your thoughts on whether you think this situation is unique enough that a split system makes sense.

    Great forum, thanks in advance.


    • Matt – Thanks for the post and well stated situation. You raise some really good questions so I will try to provide a few suggestions.

      First of all, you have properly identified some unique challenges for removing heat from your media room – southern exposure, south and west facing windows, Phoenix heat, AV equipment heat source, etc. One other important point you made is that there are no return air ducts in that room. When you shut the doors to that room you are probably reducing the cool air delivery to and heat removal from the room significantly. Basically, the air pressure in that room with the door closed will build up and prevent cool air from coming in as fast as it should. There is also no way to remove the heat generated from the windows and the AV equipment since it has nowhere to go. You get reduced cool air coming in plus you are not getting rid of the heat being generated.

      Many people think air conditioning is about simply providing cool air to a space but it is also about “removing the heat” from the space – especially in Arizona where humidity is not the main problem. So, here are a few things you can try to get some of the heat out of that room. I have seen some people cut vents right above the doors to closed bedrooms or high on any wall that leads to another room or hallway that is connected to the air returns. Just put some diffusers on each side like you have on your cool air supplies. One other approach I have seen is to put a “transom “, essentially a little fold out window right above the doors to your room. In the years before AC was common, you used to see these in public buildings to allow heat to exit the rooms into a ventilated hallway.

      Before you do any modifications, I would suggest experimenting by leaving the doors wide open on some hot days to see if you can get the temperature down with only the improved return air flow through the open door. You might also have to augment with a ceiling fan or other well positioned floor fans near the AV equipment. I am assuming you already have thermal shades on the windows but if not, that might also help when the sun is out.

      If none of that works to get the temperature down in that room you might have to talk to an HVAC contractor about getting more cool air to the room and adding a ducted return. While the contractors are there, have them do a load calculation to make sure you have your equipment sized right for your particular application (window, southwestern exposure, AV equipment, etc). You might need to talk to a few different contractors before you get one that really understands your unique situation so be prepared for the time and effort required for these important meetings.

      If the contractors decide your system is simply too small for the unique load conditions in that room and your current central system is pretty new, talking to them about adding a ductless mini-split to that room is probably a reasonable solution. However, I would also have them address the air flow problems while they are there so your new mini-split and central system can work together more effectively.

      If your system is older (e.g. maybe 10-15 years old or more for a heat pump in AZ) or has needed increased repairs recently, you might be looking at total system replacement in a few years anyway. If this is the case, you might want to go ahead and get a new ducted central system, sized properly for your current overall requirements and have them also look into fixing the return air issues in your media room and adding some zones if you want. Some high efficiency systems are available that provide both energy cost savings and improvements in comfort and sound performance so I would ask the contractors talk to you about those options as well as any utility or local rebates that are available for high efficiency equipment.

      In any case, we usually suggest getting at least three quotes from qualified contractors for both ducted and ductless solutions if you are still undecided. I hope these suggestions are helpful.

  128. I have a 168 ft studio/ playhouse I would like to hear all winter….in Wisconsin. I do not want propane which is the one that usually pops up. I saw these and thought 2 birds, one stone. Would you consider this a viable option?

    • Amanda – that would work for summer air conditioning and also for heating on days and nights when the temperature is above about 20F. When it gets really cold outside the mini-split unit would probably be running on electric resistance heaters which are expensive and not very energy efficient. Ask a few contractors what they think but you might need another heating source to go with your mini-split A/C heat pump as it gets pretty cold in WI. Hope this helps. Good luck with your HVAC project!

      • sorry, meant to say “expensive to run”. the backup heaters are internal and usually built in to the mini-split heat pump systems a standard equipment. They just draw a lot of electric power when it is really cold.

      • Why keep repeating the myth that mini-splits would “probably” run a resistive heater. Modern mini-splits like the popular Fujitsu and Mitsu do not have resistive heaters at all. Their best models use the air source heat pump all the way down to -15F at a reduced capacity, though full capacity can maintained at temperatures above 0F. Now the COP may not be 3:1 at -15F but at temperatures above 0F it would still be well ahead of electric heat.

        • Hi dm – These are all good points so thanks for sharing. I believe the comments we have received on this topic and the research that was done by the DOE recently (http://info.ornl.gov/sites/publications/Files/Pub34446.pdf ) would support your point that the capacity and efficiency of heat pumps will fall off significantly as the outdoor ambient temperature falls. Heat pumps can be very efficient when they take heat that is available in the outdoor air to move into your home but when it is really cold outside there is just not enough heat energy in the outdoor air to move inside. As you pointed out, this could affect the overall heating capacity of the system during these cold periods and could also affect the discharge air temperature which affects the comfort of the occupants due to cold air drafts.

          Also as you mentioned, some newer premium systems in the market now have the ability to augment this shortfall by over-speeding the compressor to generate higher internal heat of compression at lower ambient conditions. However, while this heat of compression method is more efficient than resistance heating it is still less efficient than a heat pump running at higher ambient and probably less energy efficient than conventional gas furnaces or boilers they might be replacing (depending on the system) and this is the question many of our readers have been asking. The issue you also raised about reduced heating capacity at low ambient conditions is also very relevant in Northern climates. Using less heating capacity when it is really cold outside for extended periods may not be an option if the heat pump is the only heating source in use.

          We will continue to research this topic and should have some new data to share in a few months. Thanks again for your comments and suggestions as we should have been more clear about the over-speed methods used in certain systems.

  129. Situation:
    Need to replace an older HVAC forced air gas pack now as it is dying. However, planning on a major remodel in the next 18 months. Walls are to be moved and removed. Some rooms combined.

    Once installed, how easily is it to change the wall/floor units to a new location in the house? Would that be super expensive?

    • Hi Wayne – We always recommend getting multiple quotes from different contractors for different types of systems, especially when the job is complicated. It sounds like you need an interim solution and a long term solution once you get your layout established. I would run both these situations by at least three or more good contractors to see what they have to say about it. For example, the cost might depend on how long or complicated it is to run and move the refrigerant and condensate lines and whether they need to be lengthened, etc.

  130. I am debating between central air and a heat pump mini split. We have a 1400sf home with forced air heat so we have ducts. Right now we cool the house with a window unit in kitchen/family area and a portable unit in bedroom. The HVAC guy says an 18k btu unit installed in kitchen/family area will cool whole house if we use our ceiling fans and/or fan from furnace to circulate the air. The 12k window unit cools most of the house except bedrooms so this seems do-able. The cost difference is $200 less for the split and the mini split has a $1k tax credit making it significantly cheaper than the central ac. I am torn about which way to go. Any suggestions?

    • Hi Kat – Here are a few thoughts and suggestions. You will probably see improvements with mini-splits over your existing window AC units in the form of energy cost savings and you will also get the benefits of remote control for each unit and you will get your windows back. On the other hand you will also now have some new indoor units hanging on the walls in your living spaces. In general, mini-splits are better systems than window AC units in most ways but they both lack the whole home air flow and filtration you get with a central system. Relying on ceiling fans to move air from one space to another is an option to augment this but it costs money to run those fans too and that cost is not always captured in the literature and energy use calculations.

      If you went with a high efficiency ducted system you could get equal or better whole home efficiency along with whole home air flow and air filtration and you might even qualify for additional utility and government rebates depending on where you live. Other advantages of high efficiency ducted systems could include better humidity control, sound and temperature control benefits. You can also view and search other the posts on this site and this article specifically to hear more about some of the experiences people have had with various systems in hot, humid climates. For example, over-sizing a system for a space (e.g. 18 versus 12) could cool the air in the space well before it has a chance to adequately remove the humidity so you might ask some contractors about that as well if you live in a humid area.

      In conclusion, will you realize benefits from upgrading from your window units to mini-splits? The answer is “probably yes”. Could you realize even more comfort and energy savings and rebates from a ducted central solution? That answer is also “probably yes”. You could also ask contractors to quote a central heat pump system and leave your gas furnace in place to get a “dual fuel” system which could give you the benefits of having both gas and electric heating options and save even more on energy.

      Bottom line – you should get multiple quotes for both approaches (ducted and ductless) from more than a few contractors before you decide and make sure they also quote high efficiency systems with any state and local utility rebates. I know this takes time but this is a big, long term investment. You might also ask a local realtor which solution will be more likely to enhance your home value in the long term.

      It really boils down to what you want out of your HVAC system for both the short term and the long term. Good luck with your HVAC project!

  131. We have a 1400 sf house in Lubbock, Tx, where our son and roommate live. It has central air and heat, but the bedroom farthest from the unit just does not cool. Humidity is not a problem in Lubbock, but blowing dust is. I have been considering a Mitsubishi ductless system (small unit) to help cool that bedroom. Any suggestions?

    • Hi Peggie – ducltess mini-splits can usually provide effective spot cooling to reduce some of the “end of the line” problems like you described. You can just use the mini-split in conjuction with your central AC but you should have the contractor calculate the size (capacity) you need before you install it. Here are some other, lower cost options you might want to try as well. If you reduce the air-flow to some of the other vents in your home you might get more airflow to the fartherest bedroom. You might also ask your contractor if your blower motor can be set to run a little faster or you could use fans to get the cool air down to that space. Hope this helps.

  132. Living in Miami Beach, I struggle with humidity control more than anything else. My home is comfortable and uses three central A/C zones. Never had an issue. My garage, which I converted into a “brewhouse/mancave” was also fine with a wall mounted a/c unit, especially after I sealed up the garage door to eliminate leaks and insulated it and the roof. The wall unit however was very expensive to run so I decided to spend about $1200 on a mini split. I have regretted that decision because the humidity in the garage is often at 60, 70 and even 80%. It’s not RH because the mold issues that have arisen say otherwise, not to mention that one can just feel it. I have to set the temp at 63F AND open the door (not the main door the side door that connects the garage to my house) in order to bring the humidity down to a comfortable 50%. But to get there, I have to have the temp on very low. The manufacturer (Ecox) is ZERO help.

  133. look like you have walmaunt AC unit :), thats like helicopter.
    Just put in you bedroom Fujitsu 9RLS3. Thats hi ef single zone 33 seer.
    You an see big difference on bill and no any noise. If you like install AC by yourself i give you some advise just sand me email

  134. Would a mini split system be a good fit for a 2 bedroom 800 Sq foot condo? The current HVAC system sounds like a 747 jumbo jet taking off in the living room. Are the mini systems quieter?

  135. I’m glad I found this page for POVs that are not “commission-based”! I have some experience with ductless from a prior house that had a combo of ducted CAC plus a Mitsu Mr Slim in one upstairs area (approx 600 sf) to which ducts could not be run. The Mitsu did a great job of cooling that room with the door closed.

    My next house will be a high-ranch (aka raised ranch) with about 1000 sf on the ground level (slab on grade) and another 1000 sf on the upper floor. Because the downstairs rooms will be rarely used I’m not planning to use AC there at all. The upstairs has a livingroom, dining room and kitchen all open to each other; the other end of the upstairs has 3 bedrooms but only 1 will be used as a bedroom — the other 2 will be converted into a very large closet plus a computer room. I don’t need or want cooling in the closet room or bathrooms. The bedrooms are small (the largest is only 120 sf and that’s the bedroom) and I absolutely don’t want a wall-unit minisplit — hate the look of them, honestly. And even the quietest models are too loud for me (I’m used to the silence of the ducted systems).

    I’ve asked two different HVAC companies why I could not simply install a single 18,000 or 20,000 BTU wall unit on whatever living room wall points toward the bedroom hallway (or else two smaller units, one in the bedroom hallway and the other in the living/dining room area). They all said “mini splits aren’t designed to work that way, you need one in every room that has to be cooled”. Truth? or selling tactic??

    There are only 3 rooms that I care about cooling, and in my climate the AC season is mid-June through at most mid-Sept (more likely to be just June/July/August):
    (1) bedroom, from 9pm to 9 am
    (2) computer room, whenever I am actually in there (an hour or two now and again during the day; never at night)
    (3) the living room/kitchen area, 6pm to midnight

    Cooling the rest of the house is a waste of $, frankly.

    I was thinking about having one of the ceiling-mounted options (“cassettes” they seem to be called) in just the bedroom, computer room, living room and kitchen,and having them each on a separate thermostat to be used only when needed. But those are ducted options, aren’t they? And if they are ducted, then where are the returns? I was also told by the HVAC companies that this would be a “waste of money” and “wouldn’t work properly”. :-/

    Thanks for any advice from a non-sales point of view! 🙂

    • Hi Marylin – First of all, thanks for your positive comments about our site – we appreciate hearing that!

      Here are a few thoughts.

      Mini-split “cassettes” are ductless. The air returns are built into the indoor unit that goes in the ceiling.

      One issue that contractors might be concerned about when using ductless mini-splits in your space is air flow between rooms. Most residential ductless systems are designed for a predetermined space, like a room. Even if a larger space is open to it, the air flow may not reach all areas of a large space and there is usually no provision for sharing air flow among the spaces with fans or other approaches

      Another issue they might be concerned about is providing adequate air flow (filtration, make-up air, humidity control, etc) to the spaces you are not planning for air conditioning. Having spaces with no HVAC will experience both temperature and humidity fluctuations and might become stagnant during times when windows are closed.

      One approach you might want to consider is using a conventional ducted system with variable capacity. Most 16 SEER or higher systems have at least two steps of capacity along with a variable speed indoor blower (fan coil) for whole house air circulation.

      Since you are wanting to zone off significant areas within your home, you could do this with zoning management damper systems or you could just manually shut off the vents in the rooms you do not want to cool. The capacity modulation feature within your new system will be able to “step down” to meet the reduced demand from the smaller space. If, at some point in the future or on really hot days you might want to cool those other spaces and the system could “step up” to cool the whole house under those scenarios.

      You also did not mention whether this home has existing ductwork but if you already have ductwork this solution might provide some lower cost options. The low stage air flow on two-step and variable capacity systems is also really quiet (e.g. at night when trying to sleep).

      We encourage consumers to get multiple quotes for both ducted and ductless systems to make sure you are satisfied with your new system. Whether you go with a ductless or a ducted system (or a combination of both) it is really important for you and your contractor to discuss what capacity (how many BTU/H) you need. You should both agree on the overall cooling (and heating) needs for your space so you can avoid being short on extreme days and also keep the air moving and humidity low on more moderate days.

      You might also want to consider the resale value of your home in the future. If a potential buyer is not familiar with ductless systems and wants more air conditioning in the lower level and other rooms they might be less interested in buying your home. Keep in mind that HVAC investments are long term investments and involve long term commitments.

      I hope you find this information helpful. Good luck with your HVAC project!

      • Hi Frank, Thanks so much for your insights! Actually I’ve had the variable speed high-SEER Carrier ducted systems in my last 2 houses and I agree, they are great units. Both houses were colonials and so I had a separate system (compressor/air handler/filter/thermostat/ductwork) for each.

        The problems I’m facing now are issues of health and cost. The prior owners of the house I’m buying had cats and the previous ones had dogs — existing CAC dates from the dog owners — and I have severe allergies to the proteins from both. I’ve learned through experience that duct cleaning is useless and that I need to remove the entire old system, including ducts and all equipment, and replace with new. Unfortunately for a job like that, even if doing just the upper floor, I’d be looking at a $15K job minimum. As a senior on a fixed income, I can’t justify that kind of expense for something that I will probably use for a total of 60 days out of 365. Also, allergy-wise a non-ducted system is far preferable to anything with ducts. The house actually has forced hot air gas heat which I’m going to have to convert to gas boiler/baseboard for this reason.

        I do understand the dilemma about conditioned/un-conditioned rooms and spaces, but that brings up another question: What about all the houses that have window or through-the-wall air conditioners in only certain rooms? For example, in the family room and the master bedroom only? Although that isn’t something I’d want — for one thing I could never sleep in a room that had a window AC running — does that mean the same problems of air movement, humidity, etc exist in that scenario? It seems to be the same premise (individual units with their own integral return and delivery system) as having cassette mini-split units only in certain rooms.

        As a senior with mobility issues it wouldn’t be practical for me to have a system in which I had to get up on ladders to manually shut off or adjust vents in various rooms; basically I need something that can be controlled with a wall unit or remote.

        Not worried about resale value, as this will definitely be my last house — dealing with the next owner will be someone else’s problem, not mine, LOL.

        On reflection, if an unconditioned lower level (cool air sinks, hot rises) would be a major problem, I would be okay with putting one of the wall-hung units (a la Mr Slim) in that area, because it will be rarely used. It’s just an open area, a storage room, a half bath, and a laundry room. I just don’t want a big ugly wall unit in the part of the house that I use constantly. A unit down there could just be set to “dry” rather than cool.

        • Marilyn – in answer to your question, window AC units and through the wall units all usually have the same challenges with extended air flow and filtration in large spaces. On the topic of duct cleaning, I have never tried those services since I have a large air filter in the system which seems to take care of any dust or debris. You might talk with your contractor about other methods for air flow, filtration and humidity reduction like ceiling fans, dehumidifiers and stand alone air filters. Again, good luck with your HVAC project.

  136. I am sorry but the charter for this site does not allow us to recommend specific brands or providers at this time. Thanks for visiting the site though and good luck with your HVAC project!

  137. Does anyone know the best mini splits for the money…I’m getting a quote of 10k for 3 zone mitsubishi but that is just to much so I need one not as expensive as mitsubishi but is still great quality. …any suggestions with Daikin. ..Fujitsu or carrier…

  138. I am so glad found this website,
    We live at S. California, summer is kind hot. I have house about 1500 square FT, with two story. The temperature between up and down at least 4 degree different. If we want upstairs comfortable , then downstairs will be too cold, think of put a 9000BTU split unit for upstairs , but worry about the tubing will running too long from ground to upstairs lost the effeciancy of the unit.
    What do you think of this ?
    Thank you so much have this website!

    • If I understand your approach, you are adding a ductless minisplit to the upstairs to augment your central system. By doing this, you will essentially have two zones which will allow you to keep temp higher downstairs when you are upstairs and don’t need it that cool downstairs but want it cooler upstairs. This might work but I would still have a contractor evaluate the required capacity and airflow in both spaces before selecting the unit to make sure it is sized right. On the lines, talk to the contractor about insulating the lines properly and maybe enclosing them somehow to keep it from deteriorating over time. We also recommend getting quotes from several contractors and also, if your system is older you might want to ask about other zoning options to compare before you decide. Sometimes they can come up with unique solutions after talking with you.

      • Does anyone know the best mini splits for the money…I’m getting a quote of 10k for 3 zone mitsubishi but that is just to much so I need one not as expensive as mitsubishi but is still great quality. …any suggestions with Daikin. ..Fujitsu or carrier…

    • One other suggestion I forgot to mention- if you use minisplits make sure you know where the condensate lines are that take the moisture of the indoor coil unit (on the wall) and make sure they are kept clean and not clogged up or water might overflow below the unit. Again you might consider just adjusting or closing your vents downstairs to get more airflow upstairs at night. That might help too. Sorry I forgot to add this earlier. Good luck with your HVAC project!

  139. I have a different scenario than most here. I am looking to cool and heat my detached workshop. This is brand new construction.

    The bottom floor is 1700sqft. It has a few rooms that don’t need cooling. Storage rooms mainly. It nets out to about 1000sqft of space that needs it. The upstairs (eventual office space) is an additional 400sqft. So, essentially what I have is two rooms that are connected by a stairwell. The entire shop has spray foam insulation on the walls and roof line. All the doors are insulated.

    I think a dual zone mini split is the way to go, but I have had two contractors give me quotes for a central heat and air ducted system. The quotes were for 12k and 15k. Way out of my budget! They forget this a shop and does not need to be treated like someone sleeps in there. I just need something t take the edge off and remove humidity from the air.

    I can’t get a straight answer from them. I think they are just afraid of installing ductless. How does essentially two rooms require ducted over ductless? I live in North Texas. We have extreme heat in the summer and get real cold in the winter, but not brutal cold.

    This site has been about as balanced a forum as I have seen.

    Looking forward to your response.

    • Eric – first of all, thanks for your comment about our site being balanced. We strive for that so it is good to hear. On your situation I have a few thoughts about why this might be difficult. Your work space probably has a pretty high ceiling so square footage area rules may not work. Also, air flow in high ceilings can become an issue with any system but this is especially difficult for ductless systems which tend to do better in defined, low ceiling, zoned off rooms in a home or office. The other problem you are probably having might be related to what you mentioned about the need for both heat and cooling. Using heat pumps (either ducted or non-ducted) as the primary heat source in an area that sees temperatures frequently going below 20F will require a lot of backup, auxiliary heating (usually electric resistance heaters) and these can be pretty expensive to operate on really cold days. So, maybe what is going on here is the combined need for both heating and cooling in a fairly large cubic space with no distinct zones other than the 400’ office. In any case, the contractors should do ACCA manual J load calculations to determine how much cooling and heating you need for this space.
      Here are a few suggestions. First of all, you might try getting some quotes from some commercial HVAC contractors or from those who do both residential and commercial. I would also get quotes for ducted and non-ducted solutions, or combinations of both. For example, you could plan to add a ductless mini-split (one evap) to the office area when it is finished but do the rest of the shop with conventional ducted gas heat and AC with a big ceiling fan for airflow. I would also ask them to separate the cooling and heating solutions to make sure the heat pump challenges in your geographic area are not creating the issues. You can get heat pump quotes too but you might be better off with conventional gas heat. If you have not poured the workshop floor yet, you might also consider using hot water, radiant floor heat in that space. I have seen these systems work really well for workshops – they keep the floor warm and the room comfortable but not hot on cold days.

      Good luck with your HVAC project! Hope these suggestions help you find a good solution for your space.

  140. i have a question about going ductless I have a 2400 sf two storey house with central heat/air that’s about 20 years old , I don’t realy care a ac in the basement im more interested in 2nd storey and main floor. If I put a two ton ductless upstairs would cool both floors well or should I put a new 2 ton central ac ?

    • It is really difficult to estimate how much cooling capacity you need for a given space just by knowing the square footage. If you are going to buy a new HVAC system we recommend that you have a contractor do the calculations required to determine the amount of capacity you actually need for the space you are trying to cool or heat. The ACCA manual J calculation method is a common one that many contractors use. Your situation is even a little more complicated and, if I understand it, you are essentially trying to cool/heat the upstairs with a new system and let the downstairs system as it is but, if it fails you would not replace it. One problem you might face with this approach will be load matching for the period when you have both systems and in the future, when you might only have the new, upstairs system. The contractor, doing the proper calculations can tell you how much cooling you might need for both those scenarios. However, since you are considering using both or just one system (eventually) your approach most closely resembles a zoned system with at least two zones. So, you might want to ask contractors to quote various solutions for serving these two zones (and not the basement). In any case we would encourage you to get quotes for both ducted and ductless options from a few different contractors before deciding which way to go.
      A problem you might have with simply adding a ductless system to the upstairs could be with providing proper airflow from the upstairs system to the downstairs space. In a ducted system, you get air circulation (and filtration) throughout the whole ducted space. With ductless systems the indoor evaporators are designed to circulate air in the space where they are placed (usually one or more rooms or zones) but most are not designed to share airflow among the various zones. You might want to ask the contractors about this.
      You might also consider just replacing your old system with a 16 SEER or better AC system that has at least two steps of capacity modulation. That way you can shut off the ducts to the basement when you don’t need to cool that space and but you can also cool your upstairs and still have enough capacity to cool both upstairs and downstairs. You would still get good, filtered, air flow to both zones and the system will adjust to match your needs on both hot days and on mild days when humidity management is actually more of a problem than temperature control. There are some other articles on this site which discuss this.
      Good luck with your HVAC project. I hope these suggestions help you find a good solution for your space!

  141. I read your article and comments on the min split units. Great article. My question is should I replace all my old windows first? I’ve replaced 8 windows so far. At least 8 more to go. I live in old house with original corded windows. I have one main duct from forced air to second story. Main level has plenty of duct work to all rooms. Thinking about adding central air but no ducts in upstairs bedrooms. I don’t like the look of the pipes running up my walls on the outside of my House. The two bedrooms upstairs has new Windows. Window units I worry about the windows getting ruined. What’s my best option.

    • John – If you have any attic space available above the second floor you could put one new ducted air handler there and run flex ducts or other ductwork to the upstairs rooms. This would give you two main zones – one down and one up and only one set of refrigerant lines running to your attic from the outdoor unit. Also for the upstairs unit you might consider a 16 SEER or better two step system that modulates the capacity down at night and on days in the spring and fall. That way, you would have a little overlap in cooling to the upstairs which might be an advantage on the hottest days. You can also just close the damper on the duct running to the upstairs for the times you don’t really need it. The two stage systems are pretty forgiving when you have two zones because they can operation at full capacity or at 67% capacity which might address the humidity control issues you might be having. In any case, if you take out window units you will need to add that equivalent cooling capacity back into the space otherwise your current system will not keep up. You can also get quotes for both ductless and ducted system options as well until you find a solution you like. Hope this helps. Good luck with your HVAC project!

  142. I wonder if there is anyone out there that has experienced use of a mini split in South West Florida. I have about 400 sq ft to cool, heat is not a problem.

    • Barb – I was in a rental home in the Southwest Florida Keys a few years ago that had a two evaporator, ductless mini-split. One evaporator unit was on the wall in the main living area and one was in the master bedroom. Granted, it was only March but the system did a good job. The owners put a through wall, window unit in the second bedroom and it did not do as well with cooling and dehumidification and it was noisy. I think most of the posts on this site would suggest that mini-splits are a step up from window units, especially for smaller, zoned spaces. However, we have encouraged consumers to get quotes for both ductless and ducted solution, especially for larger spaces since prices and installation costs can vary. Ducted central AC systems rated at 16 SEER or better with at least two steps of capacity modulation might also be worth considering due to their ability to provide superior air flow, air filtration and dehumidification. In any case, make sure the contractor gets your system sized properly for your situation and make sure the condensate drain lines are easy to access and are kept clean to allow proper flow of the condensed moisture out of your living space. Good luck wth your HVAC project!

  143. I’ve had a Mitsubishi dual zone in my Maryland home (1927, no ducts) for three years. Very positive. I am planning to get a second dual zone for upstairs. Just need to upgrade my insulation, but it has been reliable and ranks me well above my energy efficient neighbors and saves lots of money on utility bills.

    • Hi Eric. It is not surprising to see significant improvements when a homeowner replaces window/room air conditioners with ducltess mini-splits. Homes without existing ductwork that only have room/window air conditioners seem to be ideal mini-split applications – especially when zoning is a critical need. However, we have encouraged our readers to get quotes for both ducted and ductless solutions and to consider the relative benefits before making their final decision. I had both sytems quoted in my home that did not have any ductwork and the ducted solution was both cheaper and provided superior comfort and energy saving benefits. This might not be typical for all homes but I have seen this in other posts as well. It is good that you have been satisfied with your solution and I do not doubt you have realized both energy savings and comfort improvements as well. Thanks for your comments.

  144. Frank makes great points. I did not read all the post but i would add to Franks article a discussion about the heat. I deal with Fujitsu and they have moved away from the”ac only” units. If you live in a cold climate the heat pump could be a problem. In nj the cost of my natural gas fluctuates between $4 and $8 per million btus i calculate the mini split to be around $16 per million btu. I just did a whole house with mini splits but i used the mini duct in the attic with conventional registers. If sized properly i think the zoning aspect is really good. If we be honest though. Sometimes the debate should not be between conventional split unit and mini split. But mini split and window unit! They are not “cool” and not the most efficient but for $200 with no install cost sometimes i have to tell the customer to just buy the window unit.

  145. Would anyone know what the clarence of the outside condenser mini split fan should be from your neighbor home?

    I live very close to my neighbors condo. It’s less than 13 feet from fan to neighbors bedroom window. I would assume the hot air from the mini split fan will into the house. I can’t find any info on what the distance should be. Is there a minimum of distance?

    Any help would be appreciated.

  146. I have a 4,000 sq ft home with no unit at all. we have considered a dutchless unit and the contractor said we will need only 2 units my questions is, is that enough for such a large home. And how good is the heating for I live in south Alabama but I gets cold easily and do these things leak when they run for a long time or do they have a drain line

  147. I would like to share a few thoughts on these mini-splits which are so common and popular in Asia and other parts of the world. My husband and I moved our family to an urban location in Asia a few years ago and the apartment we are in has five mini-split units indoors with multiple outdoor units on the balcony.

    The units provide adequate cooling in the rooms where they are placed, BUT we need to use fans to balance the cooling throughout our apartment.

    They do NOT do a great job of removing humidity, in fact, we had to add four dehumidifiers just to keep our home comfortable.

    We had routine issues on the indoor units with significant leaking. The condensate pipes would clog and then water would just start pouring out of the unit. We had to have the drywall replaced on multiple rooms due to the damage. (In the living room alone, it needed replaced twice).

    In summary, I really miss the US style central AC systems which seem to do a better job with balancing the cooling and removing the humidity. I would NEVER put a mini-split in a USA home! I would consider it over a window unit, in an addition space, say above the garage if the cost of adding an entire central unit was too much.

  148. I enjoyed your article.
    I have a 3600 sq ft home with three bedrooms. I am considering dual ductless systems. The first would be a five zone unit with 5-9k evaporators. 4 for the bedrooms and one for the main hallway\laundry area. My question for this is the smallest unit available is 9k btu and the bedrooms are 10×12 and 12×12. Using the rule of thumb 6k btu per 250 sq ft would I have too much HVAC and would that be bad? I live in south Louisiana so heating is not an issue. My main concern is that too much ac would lead to short ac cycles and ineffective humidity removal. Are my concerns valid?
    The second zone would be for the living areas and kitchen. Two 9k and one 12k (in the kitchen) one 12k for the den.
    In the purposed system I would like to use the cassette style evaporators. I plan on opening a wall and concealing the refrigeration lines, so I am not concerned of how they look.
    Thank you in advance for considering my questions.

    • Thanks for your post. Basically your concerns are all very valid – especially since you live in an area where humidity removal can be as much of a problem as temperature control. Here are a few comments and suggestions. First of all, we do not recommend using “rules of thumb” for any HVAC job because these do not take into account the amount of insulation, number of windows/doors, geography, sun/shade, etc., which all factor into determining the cooling needs for your space. Most HVAC contractors use a “Manual J” calculation to determine unit sizing – see link http://www.acca.org/homes/

      In the case of mini-splits with multiple evaporators, you might need to check the capacity for each evap relative to the space you are trying to cool since there is often not a lot of air circulation among the various zones. If you get one of the units sized wrong it can become a real problem for that space and it might also affect the temperature and humidity in the other spaces too. Your concerns about too much AC capacity leading to short cycling and humidity problems is “spot on”. You will need to watch this closely and find a contractor who is on the same page with sizing for both sensible (temperature) and latent (humidity) loads along with the air flow throughout the various rooms to avoid temperature and humidity problems. These can cause mold, mildew, and other air quality problems which can, in turn cause health problems. This is especially true in humid areas like Louisiana.

      Your placement of the evaps sounds reasonable but there are two things you should discuss with your contractor before you go forward. One concern is the insulation of the refrigerant lines. If these lines are running through an unconditioned space, then the insulation in the tubing needs to be really good or you will lose energy to cooling a space that you are not living in (attic, exterior walls, crawl space, etc) and this can really affect your overall energy costs. The second is to make sure you are on the same page with your contractor about the location of the condensate lines (which take the moisture from the humid air off the evap coil and drain it somewhere outside of your living space). If these become clogged, all that draining water could run into the living space right below your new evaporators, possibly causing damage to walls, carpet and furniture. Make sure you know how to inspect and clean these drains periodically.

      One last thought – This all seems pretty complicated and expensive. I tried getting quotes for mini-splits like this in my home a few years ago and the cost was a lot more than the simple, central AC system that I ended up buying and years later I am still very satisfied with my decision to stay with a central ducted system. You might also try using two small central systems to zone off the main areas in your home and then use manual or automatic duct dampers to control rooms within those spaces if that is a concern. The air filtration and humidity control appears to be better with central air systems – especially in hot, humid climates. At least that is what some of the posts on this site are saying. In any case, it would be good to get a few qualified contractors to quote both central systems and mini-splits before deciding. Good luck. Hope this helps.

  149. HELP!
    I have a colonial about 2800 sq ft. I recently had two split units Air \ Heat installed, one in my dining area and a larger one in the family room. Mainly because there wasn’t anyplace to put duct work. I was talked into getting both heat and air because it was supposed to save me money on oil. A unit with duct work was installed in my attic with vents in all the upstairs rooms. Two big units are outside. I paid a lot of money for this. It was installed in October I tested the air conditioning which seemed to work fine but not needed at the time. I also tested the heat which worked, but again not needed at the time. I was told just turn your heat off at the thermostat to save oil and let the split units and the unit they put upstairs heat the house. My normal electric bill was between $98 and $110. In November I got a bill for $256 which I thought was high but if I wasn’t using oil?? In December I got a bill for $469. Never in all my years did I ever use that much electricity! I live alone and work 50 hours a week and spend many weekends with my grandchildren. This can’t be right. Obviously I had to turn them off an use oil. I am afraid to turn them on for air now!!

    • Hi Elaine – Here are a few things to consider. First of all, most heat pumps sold into northern climates have backup auxiliary resistance type heaters which use electricity. These aux heaters are usually designed to automatically turn on when it is really cold outside and the heat pump would have trouble keeping up. While heat pumps can be very efficient when the outdoor temperature is above 25F, heat pumps on aux heat are often not very cost effective when outdoor temperatures get really cold, like they were in many parts of the US this past winter. These electric- resistance type, backup heaters can be pretty costly to use for your primary heating source, so on really cold days (and nights) you were probably using a lot of energy. Some people avoid this problem by running their conventional gas/oil furnace or boiler on the coldest days or when the cost of gas/oil is favorable to the price for electric power. This is called a “dual fuel” system – which, since you kept your old system, you already have. Sometimes heat pumps have lights or other indicators that tell you when the aux heat comes on so you might check the manual on your new system to determine what to watch for – or you can just watch when the outdoor temperature is going to be lower than about 25F. For those periods you might want to shut off the heat pumps and just use your fuel based heating system. When the temperature comes back up (above 25F), you can switch back to the heat pumps and turn your boiler down or off. Using this method you might keep your combined electricity and oil costs lower than just running the oil heater but you have to watch both the outdoor temperature and the relative costs of oil and electricity to make it work.
      For air conditioning, it is not clear what you were using before, but if you were using window units, the new systems will probably be more efficient. However, if you added more overall cooling capacity or run them more often, or keep the house cooler than you did before you may end up using more electric power. Since you have several “zones” with the new system, you should be able to separate and cool only the spaces you are using and this might also help you manage your summer cooling costs.
      I hope these suggestions help you in both the cooling and in the fall when you switch to heating.

      • “most heat pumps sold into northern climates have backup auxiliary resistance type heaters which use electricity”

        I dont believe this statement is true … at least not the good ones … e.g. mitsubish and fujitsu to name a few.

        • Thanks Lawrenc – you were not the only visitor to point out my confusing comment about aux heaters and I think I corrected this in a previous post. You are correct that some of the newer mini-split systems do not use aux resistance heaters at low temperatures. They do however achieve desired heating capacity by running the system at higher speeds. Testing shows that this is not as energy efficient as a system running at lower speeds and the absence of heat in the atmosphere on a cold day adds to the energy challenges of a cold climate heat pump. I agree with your later post that suggests the only way to really know your energy savings is to do a side by side comparison of actual fuel costs but that is also challenging due to differences in day to day ambient conditions as well as differences in the size of the space that is being heated and the set point temperatures. Thanks for supporting the site and I appreciate your comments and insight. We will keep watching for new information on cold climate heat pumps and post this as it comes in.

    • Responding one more time to this one as this really touches on probably the largest concern about the mini-splits …. how do you tell if they are really costing less to heat ?
      Most folks are probably switching from some other form of heat … lets say oil. In theory the mini-splits should cost less than oil (although at the current $2/gallon range … not so much less! but still). And despite what Frank has said, modern mini-splits in theory, work VERY WELL down to 0 and even below 0.

      So the only way to tell if you are saving money is to compare what your prior fuel consumption was to what your current electric cost is with the mini-split.

      Elaine’s bill of $469 does seem very high to me but first question should have been … how many gallons of oil were you previously using under similar circumstances ? … similar outside temps and similar settings for your inside thermostat?

      Again, there is LOTS of supporting evidence that suggests mini-splits should cost less than almost any other form of heat. So if its not then something is wrong.

  150. My wife and I live in the woods in rural north Florida. We have long hot humid summers and relatively short cool to semi cold winters. Our 5 room 1200 sq ft home is an older cedar shake house and has a cross shaped footprint with the 5th room in the center. We have a traditional heat pump with outside under the house duct work. The heat pump is working but 20 years old. The duct work is in awful condition full of leaks and laying on the ground all patched up with duck tape and plastic wrap. The idea of abandoning the duct work and having a ductless system is appealing. We are trying to weigh the advantages of both systems as essentially we are starting over. We do like the idea of no duct work exposed to the outside as we get no value from the air lost through the ducts…some critters love it! We are not young so lower upfront costs can mean more than a small monthly saving. We currently zone by closing/partially closing doors and using the floor vents so individual room thermostats is not that important. Thanks for any advise!

    • Paul – It seems like you have properly identified the separate problems you are facing. First is the inadequate ductwork which is leaking into the unconditioned crawl space under your house. If you stay with a conventional ducted system this should be replaced with new, insulated ducts. There are new, flexible ducts on the market now which might allow you to address this problem without too much expense. The second problem is the age of your current AC/heat pump which is probably only about 10 SEER (efficiency) given its age, and a new system is going to be at least 14 SEER which might provide a as much as 30% to 40% reduction in your annual energy costs irrespective of whether you buy a central, ducted replacement system or ductless mini-splits (note: both ducted and ductless systems are subject to the same efficiency regulations which have recently gone to 14 SEER in your region).

      On the question of ducted versus ductless, there is a lot of material on this site that might be helpful to read before deciding, but here are a few thoughts and suggestions.

      Ductless: We have had a few posts by people who have had issues with properly sizing of the capacities and also with proper dehumidification in really humid regions like yours, so make sure your contractor addresses these issues. Also, make sure the contractor properly installs the drain lines from each unit so they drain out of the house (this drainage is the humidity, or moist air that is removed from the air in your house) to avoid growth of mold or mildew. The other issue with ductless we have heard of is the lack of central air flow and filtration throughout the house during both the heating and cooling seasons. So, you might discuss the airflow issue with your particular floor plan since the placement of the indoor units in the various rooms is important and the units need to be positioned to help address air flow through the whole space when you need it. I would also think about areas that you frequently zone off or keep at a different temperature than the rest of the house as this is one of the main benefits of mini-splits so you might as well take advantage of it.

      Given the layout of your house, I assume you will probably end up with two small mini-split units with two or three indoor units – one in each room. Make sure the capacities all add up to about that of what your current unit is rated in BTU per Hour (BTUH) or have the contractor do a new calculation to determine how much cooling you need. If you do not get enough capacity, your system will not keep up on the hottest days. If you get too much capacity, then you will cool down your house so fast that you will not get enough air across the coils to remove the humidity and drain it to the outside. Whatever system you decide to buy, it needs to be sized properly by the contractor to insure comfort in your humid area.

      One last thought. If you go with mini-splits, you might have them leave your old system in place as a backup in case you run into sizing problems down the road. In any case, I would get quotes from three or more different contractors for all three project scenarios – one with mini-splits, one with a new central air/heat pump and one for replacing the ductwork. After you find a quote you like, make sure you and the contractor are on the same page with how you want the job to be done and how he addresses your needs. I hope you find these suggestions helpful. Good luck with your HVAC project!

  151. The information contained is easy to read, concise, and informative. On the other hand, there are instances that might be misleading. I had to scour through comments to find the context of how central AC is supposedly more cost-effective. I suggest including clarification, stating that this cost is based on pre-existing duct work, which is a substantial capital investment.

    Also, it would be great to see actual values and equations for energy loss calculations. Of course, the design requirements must be the same and all variables must be practically considered. I think that would be a great way to further remove bias from this already well-written and well-rounded article.

    I would also suggest clarifying your statement about energy loss in “conditioned” environments. It depends if it is the air return or supply. If there are losses in the return, you increase the amount of energy required to cool the system because of the additional heat (or lack-there-of for heating applications) redistributed in the system.

    • First of all thanks for supporting our web site and I appreciate your suggestions about improvements to this article and related posts. We will keep these in mind for future articles and content on this topic. BTW, You might have already seen this but on March 9, 2015 I provided a link to an independent study was done by the DOE at their Oak Ridge National Labs (ORNL) which might provide answers to some of your specific questions. I also provided some suggestions in the 3/9 reply that might also be helpful to you. Here is the link to the complete report. http://info.ornl.gov/sites/publications/Files/Pub34446.pdf –

  152. I left a reply to a comment above, but would like to add my 2 cents as a future mini split consumer. I have a one story home built in 1979. We recently found termites so I basically have everything gutted.

    I am addressing the house first. This is most important, caulk and gap filler and new insulation is first! Second I will be installing Blueridge mini splits as they are so inexpensive.

    I am going with 2 separate systems. One 2 zone for one side of my house achieving 18 seer, and a 3 zone for the other side of my house achieving 16 seer. I will be installing all units and then have a licensed HVAC guy place refrigerant and vacuum the lines. All in all I will be able to do this install for right around 4.5k.

    I chose Blueridge for the cost of course but I have yet to find a bad review, and so far the customer service has been top notch. I work in IT and I see these mini splits in all of our server rooms and they do a fantastic job, not to mention one of ours is currently 10 years old and will freeze you out of the room! It still works like a champ. The warranty is 5 years on the compressor, and one year on parts. I recently have had 4 HVAC quotes and no one has been able to match the price for a whole home system with ducts so I’m going the mini split route. Wish me luck 😉

    I will update my install as well as my experience with Alpineair.com


    • Hi, Joe,

      I haven’t found another post from you, telling us how your installation went. I am very interested, as I also think that this could be a possible DIY project.
      I’m still researching and your experience can surely help. Thanks!!!

  153. I am looking to have heated/cooled space in my basement. It has three main rooms and is about 750 sq ft. I have been told the two best ways of doing this is to alter my current ducted system that is in my basement for upstairs into a zoned system with baffles or a ductless system. The ducted system addition was quoted as costing about $6,000 and the ductless system about $4,300. I don’t really need a lot of heating or cooling as the basement temperature is fairly comfortable most of the year. The very hot days and the very cold ones are the issue. It seems like I could get a new system for the basement for less than $6,000 so I don’t understand that cost. (I will be getting more quotes) Would a ductless system be just what the doctor ordered in my case or can an existing system be appropriately zoned to handle a basement?

    • Brad – It sounds like you are on the right track but I would suggest continuing to get a few quotes from different contractors who might come up with some new configuration ideas. Retrofits can be tricky and sometimes contractors can come up with some creative ways of solving problems like this. I will throw out a few other ideas you might want to consider or discuss with your contractors.
      First of all, consider the age of your existing ducted system and how it is sized. Adding a significant percentage increase to the overall space that is being conditioned might affect the comfort you experience in the rest of your space. You did not tell us the overall size of your home or the capacity of your existing system but adding a bunch of space to your existing system demand might not give you a system that can keep up on extreme days. The additional run time might also really stress an older system and lead you to replacing it sooner than you were planning. On the other hand, if your system is older, and has lower efficiency, and you might be replacing it soon anyway, you might consider adding the duct additions and zoning but upgrade the system to one with capacity modulation so when you shut down certain zones the system can adapt to it and keep the air moving through the rest of your house. Conversely, if you already have a newer, 16+ SEER modulating AC system you might not have any problems at all with adding the additional space because the modulating system could more easily adapt to the additional demand. You might want to ask your contractor about this 16+SEER modulated option and the status of your old system – if not now, at least when you eventually replace your old system. Just keep it in mind.
      Another point to consider if your existing, fixed capacity system is newer and you decide to go with mini-splits would be a “hybrid” approach. Ask your contractor if you can add a mini-split to the basement space and add just one or two of the easier supply air drops and a return air drop to the basement space from your old system (should not be too expensive since it is already in the basement). This way you would get the benefits derived from whole house air circulation of your basement air through your central AC system which might give you better filtration and better humidity reduction. The additional capacity provided by the mini-split might give you a little better temperature control in the basement relative to what you have now and also reduce the additional stress on your existing system. This approach might also allow you to reduce the size and cost of the mini-split you would need. I am basing this suggestion on your statement that said you only needed the additional capacity on the extreme days. One other point – If you are in an area where humidity can be a problem, make sure you ask your contractor about air flow and humidity issues which can be difficult with basement spaces.
      In any case, make sure your contractors consider how much capacity you will really need and also ask them about maintaining good air flow into and out of the basement space. Good luck with your basement retrofit!

  154. Hello to All,
    I recently bought an old home built in 1880, totally restored, but without air conditioning or duct work, so I am getting quotes for a mini-split system.
    I only need two units, one upstairs and one on the main floor. Each area is small, less then 800 square feet. I was surprised with the first quote (haven’t received the others yet) that was $7,000! The contractor stated that these systems save at least 1/3 in heating costs so the return on savings over the years makes installation of the mini-system cost-effective. I wonder if anyone knows just what the heat energy savings (over oil heating)
    actually is? And, do you think $7,000 for a very small house is a reasonable price? Thanks.

    • On your question of energy cost savings, mini-splits can save on energy by allowing you to zone off (i.e. turn down the thermostat) in areas which are not in use. This is true for both heating and cooling seasons. The overall energy savings during the whole heating season will be based on several factors: the aforementioned “zoning”, the heating efficiency (HSPF) of the mini-split relative to your current heating system and also the relative cost, in your area for electricity versus the cost of fuel used in your current heating system. So, the actual calculation to determine how much you should save might become complicated and the results can fluctuate as energy/fuel prices change and whether you have a mild or severe winter. One approach you might consider would be to leave your current heating system intact and just add the mini-splits to get a hybrid approach for heating. This way you can use the mini-split heat pump on the light load days when electricity is cheap but you would still have your old heating system to use when it gets really cold and you might need it to keep up – likely in really cold climates. In this scenario you would still just have the mini-splits for AC in the summer.
      On the question of equipment and installation costs, this site always recommends getting at least two or three quotes from different contractors to make sure you are getting what you want – and it looks like you are doing this. Also different contractors often offer different types of equipment and might come up with different ways to solve your heating and cooling needs and this is especially true with older homes. Even though you do not have existing ductwork you might also have them quote a ducted system for at least one of your zones just to see how it compares. Sometimes ductwork can be retrofitted into older homes without too much cost. Good luck with your HVAC project!

    • I am getting ready to do a whole home mini split install. I found this article trying to find the current watt demand for a 20 seer mini split system. Anyhow take a look at Blueridge. It is a GREE systems renamed so Alpinehomeair.com can sell it.


      I have found this to be the best bang for the buck and the reviews are great. I will update with my install, but I am first sealing the entire house to have the best thermal envelope as possible.


  155. Marcie – here are a few suggestions. First of all, you should get some other contractors to look at your space and try to find someone who knows how to install flexible ductwork or has experience with creative ways to get ductwork from your old system into your new space. Since this is pretty big increase in your square footage (28%) your existing system will need to run longer to keep up and it might not be able to keep up on the extremely hot or cold days. On these days it will run for long periods until the temperature at the thermostat hits your set point. On less extreme days you might not notice much difference but it will still be running longer – actually a good thing in the AC season. You might try this out for one or two seasons to see if you can live with it and augment on the extreme days. If the new space is insulated pretty well you might get by with using other air moving devices (e.g. ceiling fans) to keep conditioned air moving into and back out of the new space.
    Another option would be to install one new, less expensive, small ducted heat pump system just for that space – probably about 1 to 1.5 tons (the contractor will need to confirm this). You could have a separate air handler under the space (assuming you have a basement) or in an attic space with drops through an upstairs closet. If you can get just one or two inlet vents to this addition and a return somewhere close to your old kitchen this might work for you. This could address your airflow issues along with the shortfall in both heating and AC capacity due to the increase in conditioned space. This would also give you the ability to have two working “zones” i.e. two different thermostats to manage temperatures in each space which might also reduce energy costs. I think this approach might also address some of your concerns about future replacement of your old system too since the two systems would be independent. When you do replace your old system you might consider a higher efficiency system with capacity modulation to balance out the loads between the two spaces throughout the seasons. You will still need to shop all these ideas around with a few different contractors to get what you want. In any case, try to find a contractor who is on the same page with you before moving forward.
    Good luck!

    • Marcie – I posted a response. If you did not get an email with this response please check the site again to see it or let me know by posting again. thanks!

  156. Please help me with my dilema. We bought a ranch home built in 1978. It is appx 1900 sq ft upstairs. It has the standard ducted system which works just fine. Although I fear the furnace will need to be replaced soon as it is over 20 years old. The air conditioner is only 5 years old. We add a 22×24 room off the kitchen to make one big open family room/kitchen. One contractor told us that it would cost over $4,000 just for the duct work alone. Then he said that we would need to replace both the furnace and the air conditioner as they would not be able to keep up. His next sell was the ductless system hanging off the wall in my beautiful brand new room and kitchen. Mind you, I have spent over $100,000 remodeling/building these two rooms alone!!! He has my husband conviced that this is by far the most efficient and best way to go. I put my foot down and said that I don’t want this hideous thing hanging on my brand new wall. He then suggested putting it in the ceiling. I have a beautiful trey ceiling!!! The only place for it to go would be in the trey!! We got a second opinion and although the cost was about 1/2 of the other (exact same product) this one also tried convincing us to go with the ductless system. AGAIN, I do NOT want this white elephant hanging off of my wall. The persistance of these guys in selling us this systems borders on harrassment. My next question to which they all seem evassive, is what happens when my furnace DOES in fact go out???? Are they then going to try to convince me to put one of these in every room? When I do indeed have to replace my furnace, why on earth would I not upgrade to one that would heat my whole house? Then I will still have to add ductwork and then cover up the hole in my wall to remove the ductless system in that one room. Please please help me!!!!

    Thank you,


  157. Have spent the past 4 hours google searching ductless vs ducted systems and this site has been by far the most informative. Currently designing a new home construction project and would like to install the best overall HVAC system for central Florida. I am looking for independently tested documentation (not claims nor opinions) that a ductless system will provide better air circulation and filtration with lower humidity than a ducted system…does it exist?

    • Ray – First of all, thank you for supporting our web site and we sincerely appreciate your nice comments! As to your question, an independent study was done by the DOE at their Oak Ridge National Labs (ORNL) and here is the link to the complete report.


      The study involved a comparison of a whole home, 16 SEER, two-step, ducted and zoned system used as a baseline, and a comparable variable speed, multi-split ductless system with eight separate evaporators. The study also compared the baseline two-step, ducted system with a fully variable speed ducted system. Although the study was focused on energy use in both the heating and cooling season, sections 4.5, 4.7 and figure 11 should give you some objective information about the humidity challenges associated with multi-split systems.

      As I read through the report I also noticed that the multi-split ductless system had to be set up to have all eight evaporator fans running all the time in order to maintain proper airflow throughout the home – which was a drain on energy use, and they still had problems with humidity in the summer cooling season. Please note this test was done in Tennessee and not in Florida where summer humidity might be even more of an issue for homeowners.

      One other point you might pick up from this study illustrates one of the messages we have been providing on this site. Whatever system you go with, it is absolutely vital that you have a qualified HVAC contactor involved with the selection, installation and set up of your new system and this is even more important with the more sophisticated variable speed systems and the non-traditional (at least in the US) technologies like ductless mini-splits.

      This help site has supported the use of ductless systems in applications where it makes sense, both from a an economic standpoint and from a comfort versus complexity standpoint but it is not clear to us that these systems are appropriate for every application, all the time as some suggest in the media and in some company advertisements. It is important to research this thoroughly before deciding, and to secure multiple quotes for the various systems you are considering, and from contractors who have experience with the systems they are quoting.

      I hope you have success with your new system, whatever you decide to use. We will continue to monitor these technologies as they evolve and will post new, independent test results when they become available.

  158. This article and the comments have been very informative. As a single female homeowner with a house that has radiant heat and window air units, my only recourse is ductless mini-split because getting the ductwork would cost a fortune. What type of mini-split unit for a 6 room condo in Chicago which has extremely cold and snowy winters and horribly hot and humid summers would you recommend?

    • Our policies for this site prevent us from recommending specific brands of equipment or specific service providers. We can only make suggestions about the type of technologies which might be best suited for various HVAC situations. If you have already decided to go with ductless mini-splits for your home in Chicago I would suggest getting heat pump mini-splits which provide air conditioning in the summer and heating in the winter. However, since you are pretty far north, you might want to keep some or all of your radiant heaters along with your new mini-splits to help provide additional heating on the coldest days. One other suggestion would be to call around to a few qualified HVAC contractors in your area to get some bids on a hybrid approach – using at least one, smaller ducted central HVAC heat pump system for a part of your home that can be reached easily with ductwork and then add a few mini-splits for the rooms that are harder to reach with ductwork. In any case, be sure to get at least three quotes from good contractors in your area before deciding. Good luck with your HVAC project!

    • Glad to see I am not the only one with radiant heat and window units. Live in Cleveland..cold winters…we have no duct work and have a colonial. This seems like the best for us- the upstairs doesn’t need a lot of heat in the winter, but needs extra help in the summer. I will do more homework on this- but I have learned quite a bit reading everyone’s input. Thanks!!

  159. After reading your article. I can’t help but feel you might have maybe had a little bit of bias when you started writing. I will respectfully take issue with a few of your points.

    (1) cost. You really didn’t do an apples to apples comparison. If you have a properly installed multizone system in a house with a tight thermal envelope and your unit goes out then it will be cheaper for you to simply replace the unit and continue with a central system. However, if you met those conditions you would probably not be looking at how to get a better system. The most visible advantage of mini-splits is a thermostat in many different parts of the house. This works to both keep the house a more consistant temperature when needed or to keep the house at different temperatures when wanted. So your comparison of replacing an existing system is not at all apples to apples.

    (2) Leaking systems condition space? Most people don’t have that much exposed ductwork running through their house. Most ductwork gets pushed behind or above drywall. While, there is mass in those places and any mass at a different temperature will become a radiating thermal mass, forced air systems are attrociously inefficient at heating and cooling a thermal mass. They are specifically designed to avoid it.

    (3) furthermore how much energy does a phase change system lose as refrigerant moves through the line. While units that didn’t step down might have had this at one time, it is no longer a relevant issue. Furthermore, efficiency isn’t separable from savings. It matters not how efficient or inefficient the units really are only how those things transfer to money spent or not.

    (4) Having lived in many European and Middle Eastern countries, I will tell you hands down that mini-splits are much less prone to hot and cold spots in a house than are traditional systems. Again read the first thing, a thermostat in every room simply beats the pants off a thermostat in a central location (usually a hallway with little or no light and too far from the entrances to respond quickly to demands from entering and exiting.)

    In conclusion, I have a central air system currently. I miss a mini-split daily. I don’t think anyone who has not had the extreme pleasure of living with one can truly understand how much power they give you or how much that power corrupts your view of a traditional system.

    • Bobby – Thanks for your post in support of ductless mini-splits. One of the goals for this site is to provide both the pros and cons for various HVAC decisions faced by consumers in the US and I think this forum has provided some of both on this subject. There are many variables to consider and many different situations and various ambient environments which can make these decisions complicated, depending on what the consumer hopes to achieve with their purchase. Considering this, I agree with you that it is often difficult to find a pure “apples to apples” comparison for all these various cases as you mentioned in your post. We will continue to monitor this technology and will update our articles periodically as things evolve. Thanks again for sharing your opinions and insights.

  160. Homes that have duct work or air handling units in the attic or uninsulated crawlspace typically cost 10 to 25 percent more to operate than units with everything contained inside the insulation envelope of the house due to leaks and the fact that these units and duct work are seldom sealed and insultated sufficiently. Zoning and load matching is easier with minisplits and as another pointed out the energy to push air through ducts is saved. I agree it is more of a challenge to make a minisplit system look good, especially in a retro fit but it can be done by running refrigerant lines in chases or closets but if an existing house does not have duct work it can be easier than installing duct work in some cases. I have disguised the wall units in enclosures behind sheer fabric screens that allow for air flow but hide the wall unit in homes where people did not want to look directly at the unit and of course the recessed ceiling mount units are an option. Having individual control over air conditioning in each room and actually using it wisely will save plenty in the long run over an unzoned central ac system. Dehumidification is provided by a properly sized minisplit system so I am not sure why this was omitted from the article. Ducts collect a lot of dust and sometimes mold in most installations I have seen with time and are difficult to clean.so again this was omitted. Any dust not collected by the filter on a minisplit is easy enough to clean up from the room with a vacuum cleaner. Ducts carry noise through out a house, how bad depends on the installer and materials used, but this is another problem not to worry about with a minisplit. One problem with minisplit systems is conditioning a small poorly insulated room that is closed off from the rest of the house with a door for example putting an air handler in a small bathroom. If a house is super insulated and the bathroom has an exhaust fan this is not an issue as super insulated houses do not need to have any where near the uniformity of airflow for comfort as a typically or poorly insulated house would need.
    And super insulation will greatly reduce the cost of operation.

    • Hi Robert – Thanks for your nice post. I would like to add a few clarifying points to some of my earlier comments about my own installation which involves having a fan coil in the attic. The fan coil (evaporator) unit was in a non-insulated space but the contractor took proper care to insulate the unit and used insulated ductwork throughout. Also, on the problems with dust and other contaminants, we installed a pretty nice pleated media filter and I replace the elements every year – even though I am not sure why I do this because it collects very little dust or debris from our ductwork. My wife also has dust/mold/pollen allergy problems at times but it is much better for her when we are running our air conditioner and filtering the circulated air. Another point I should make is that my system also has two steps of capacity modulation which significantly reduces the energy consumed during the season and especially in the “shoulder” seasons of late spring and early fall. The longer run time insures a steady supply of fresh, filtered, conditioned air throughout the house, even at night. The stepped option also allows me to totally shut off a few rooms which are not in use, without affecting the comfort in the rest of the house due to the reduced overall load on the system.
      I guess my point is that if you do your homework to pick the right system for your needs, this is not sufficient to insure that you will have a good outcome. You also need to have a good contractor to size it and install it properly and also to make sure you have other things addressed like insulation and filtration that are often overlooked. Whether it is a mini-split or a ducted system that you choose, proper equipment selection and good contractors doing the consultation and installation are both essential to good HVAC investments.

  161. Hi Karen – Ducted central air conditioning technology has been in use for many years in the US and has become very reliable and longer warranty periods have become common among the manufacturers. In addition, central AC components have been designed such that they can be repaired if necessary and many spare parts are available through distribution. Ductless systems are much newer technology (at least in the US) and for various reasons often come with shorter warranty periods. However, some ductless system manufactures also offer extended warranties now but you have to ask about it because it varies from brand to brand. If you haven’t already, try contacting a qualified A/C service company in your area. They can be very creative with designing a ducted system that can fit your home. The cost of a custom duct system can often be lower than having to install 5-7 mini-split units to meet your needs.

    I installed central air conditioning into my older home a few years ago but I looked at ductless too because the house had hot water heat and no ductwork. The contractor put the air handler in the attic and ran the ductwork mostly through the second floor closets to get air to the first floor. I did not have a lot of problems with spaces I could not cool with this method but if I did, I would have considered a central air system for most of the house and then used a few single ductless mini-splits or window units for the areas that were more difficult.

    There are a few other articles on this site that deal with the pros and cons of various system technologies so you might want to use the keyword search tool to get more information. Good luck with your new AC!

      • Jan, have you looked into small-duct high velocity systems? They are great for older homes where there’s not enough space for regular ductwork. Some of the small ducts are 2-inches in diameter and are flexible, not rigid. So they can bend and sort of weave between walls and above ceilings. The ducting is insulated and doesn’t leak.

  162. Live in a very old home. Have been using window units for many years and wanted central air. No place for duct work in part of the house. Like the idea of the ductless system for obvious reasons. Through some research, I have found however that the warranties for these systems are only a couple of years compared to 10 years on most standard ducted setups? Is the reason for the also obvious in that they are not as reliable a product or is my information not correct?

  163. As a consumer, it seems to me the HVAC companies have already geared up to make ducts.
    Having watched and talked with the HVAC workers who built our addition, I understand that duct making is a learned skill, requiring varies tools and investments for the AC company.

    But the guys explained how AC’s “cool” your house, and this article seems to disregard that fact.
    So I’m wondering, how well do these system remove heat? And can something be done with that heat, i.e., heat water?

    • Hi George. Air conditioners provide cool air to the space they are cooling and also, simultaneously, remove the heat (hot air) from the space as part of a continuous, circular process. This process is described in an article on this site http://www.ac-heatingconnect.com/homeowner-behind-the-scenes-how-your-air-conditioner-works/
      This article has a diagram that shows how the heat is removed to the outdoor unit and is discharged to the outside air. In a heat pump, the reverse happens. Your question about capturing the heat that is removed is a good one. There are some products on the market that would allow you to capture some of this waste heat before it is discharged to the air and this heat can be used to heat water as you suggest. Our policy on this site prevents us from endorsing any particular companies or brands but you can do an internet search to get more information about the various products available which can “capture waste heat from an air conditioner to heat water.”

  164. Am considering a mini split system for new construction. What is experience in getting heat & AC to small rooms like a powder room or a laundry room? Obviously you wouldn’t have a blower unit to such a small space so are they heated/cooled with venting or just left alone to take in warm/cool air thru the door?

    • Jay – In a ducted system, a separate delivery duct can be run to small, separate spaces without requiring a return duct in that space. As long as the door is open to the space, the cool air will go into the space and force the warmer air out into the rest of the house and to a central return duct. If you are using only mini-splits you might have a difficult time getting air to separate spaces like those you describe if you don’t put evaporating units on the walls in those spaces. You could also consider single room AC for that space or a through the wall unit. However, we still think a ducted system has a lot of advantages over the mini-split alternatives and these would include better air flow, air filtration and dehumidification. If you are concerned about zoning off separate rooms in a ducted system ask your contractor about zoning options for your ductwork. You might want to have the contractor quote your system both ways – ducted and non-ducted, before deciding. By the time you add up all the extra evaporating units it is often less expensive to go with a ducted system. That is actually how it worked out for me a few years ago when I was adding AC to my home. I went with a ducted system, saved money and was comfortable on even the hottest and most humid days. Good luck!

  165. Kitty, I really appreciate your insightful comments. I would like to add a few points for clarification. One of our goals for posting this information originally was to help U.S. consumers and contractors become more aware of some of the issues with installing ducted systems. When sized and installed properly, these systems can be very efficient – especially where room-by-room control is a priority. They can also be designed to blend into the home or business architecture if that labor is built into the proposal. Unfortunately, this is not always the case.
    It’s also important to consider the economic benefits of staying with a ducted system (almost 80%of the current systems in the U.S. are ducted) when replacement is needed, rather than abandoning the existing ductwork to go with a ductless system. On the other hand, many older homes, especially in the Northeast U.S., which do not already have ducted HVAC, have been upgraded from window AC to ductless mini-split systems in the past few years. These seem to make good economic sense.
    On the issue of zoning, there are many ways to zone off rooms or sections of the ducted spaces in central AC systems, and as an industry we need to do more to promote the use of these zoning methods in addition to considering ductless retrofits. We will likely be providing more content on this topic in 2015, so please check back from time to time and send us your comments.

  166. Americans don’t like change. Having spent several years traveling the globe where these units are standard in all types of housing I have yet to find them to be anything but efficient. Yes there are outside lines, however none I observed in single family home was as poorly installed as in your photos. Most were invisible and painted to match exteriors. I found that heat/cooling rooms as I needed was more efficient and more cost effective. Americans waste energy heating/cooling rooms that are not in use. Myth: your whole house needs to be the same temp all the time! Truth: only the rooms you are currently using. These units have remotes/theromostasts that can regulate rooms as needed. Many of the homes I stay in are very old and somehow seem to have these units.

  167. Thanks for the article and allowing people to post comments on it, I like to hear people’s opinions and thoughts on any kind of new technology and conveniently the comment about the ducting applies to my scenario.

    I had seen these things on buildings for a while, but didn’t know what they were.

  168. Hey Jim. Thanks for your post and the earlier one from Frezz. This is exactly the type of dialogue I was hoping to get from my 7/13 article on ductless systems. I wanted to clarify one point and then offer a few additional suggestions. On the costs, my suggestion that ducted systems could be 50% less expensive than ductless was in reference to the situation where the homeowner was “replacing” an existing ducted system – thus avoiding the cost of installing new ductwork. In your case, you are considering a complete installation in either case so the cost difference between ducted with new ductwork and ductless would be much less and the overall installed cost difference might be very small depending on the type you choose.
    Considering the size of your home, it will be interesting to see how the quotes come in. Here are a few other things to consider. If you are in a harsh climate, with either cold winters or very hot, humid summers make sure you (or the contractors) are sizing the system properly for those extremes. I would also make sure you have the contractor quote the exact features you want. You mentioned, recessed, ceiling mounted evap units with internal refrigerant and condensate lines – so you will need to spell those items out when you get them quoted. There are also several types of ductless systems to consider. Traditional mini-splits appear to have more issues with energy losses in the lines than some of the newer, multi-evap VRF (variable refrigerant flow) and VRV (variable refrigerant volume) which address many of those issues – but are also a little more expensive than traditional minisplits.
    We have been watching emerging ductless applications for a while now and there are several other articles on our site which discuss this technology. You can use the search feature to find those by clicking on the “additional HVAC articles” link. We strive to maintain a balanced, objective view in our articles, based on what contractors are telling us. We do not support any particular brands or technologies but we do try to recommend options that might work best for various situations.
    We just posted an article last week that deals with HVAC options for new homes where we suggest using a combination of ducted and ductless systems so you might want to check that out. Good luck with your new home!

    • Hi Frank, I just read your comment and was wondering how you made out and if you did go with the units? If so how are they working out?
      Thank you in advance

      • Michelle – I think that was “Jim” who was considering various options for his HAVC project. I was just monitoring the posts and providing additional information. Thanks for supporting our site!

    • Hi. You said you were curious about true costs. We were quoted for new central air in our 1424 sqft house, as well a DUAL ductless system. For only 2 units, with complete installation, we are looking at $7k. We were quoted $9k for central air (no existing ducts).
      We would have gone with central, however, our Florida room would still require a ductless as it’s an add-on to the house and insufficient attic space to install ducts. As a result were going with the dual ductless, split between two 12,000 BTU units, to cool the majority house. These things are ridiculously priced down here but all quotes I received were close leading me to assume they’re roughly fair for our location.

      • HI Mh,
        How did the 2-zone ductless work out for you? I’ve been getting quotes for my 1,200 sqft house in CA and I’m seeing similar numbers for installation — although central AC option for me is running higher because I have limited space for ducts and/or furnace in the attic. Love to hear how the ductless have worked out. Also, where did you install the two blowers?

        • Hi, I’m pricing a one unit mini split systems for my 1150 Sqft cabin in the foothills of CA. I’m finding top brands by top professionals running $4000-$5000 installed, depending on a 5-10!yr. warranty and other miner things.I have a wonderful wood heating stove now that will come out. I do have a fear of getting cold in the winters.

          • Hi Suzi – your contractor should make sure your new system is sized right and has adequate capacity for both heating and cooling in the extremes of the seasons. They should do “Manual J” calculations to determine this. If your outdoor ambient does not usually get below 15F (not likely in CA) the heat pump should be pretty efficient so a properly sized heat pump should work well for you in the winter.

            I would offer a few other suggestions – with a 1150 sqft space and only one indoor unit you might not get enough heating and cooling to the spaces that are far away from or closed off from your indoor unit. To address this you could consider two smaller min-split units in separate spaces and/or you could add a ceiling fan or other air moving appliances to keep the conditioned air moving throughout your space. Some mini-splits have one outdoor with more than one indoor (multi-splits) but these sometimes have long, expensive refrigerant lines so you might want to quote this both ways in addition to the one unit approach.

            On the “wonderful wood heating stove”, why not just keep it as a backup heat source on the coldest days and nights. It would also give you a backup heater in case the power goes out. I’d keep it.

            I hope this answers some of your questions. Good luck with your HVAC project!

          • Hi
            My husband and I live in row home in phila and our sq footage is approx. 1200-1600 square ft. I recently got a bid to install a Mitsubishi 3 zone ductless system. One MSZGL18NA and 2\two MSZGLO9NA s for upstair separate bedrooms. We currently have a traditional central AC unit that only cools the downstairs NOT the upstair bedrooms where we currently have traditional window units. The estimate was $11,214 and the installers are Mitsubishi trained and certified.
            Included is a warranty that covers—2 yr labor, 12yr parts and 12yr compressor.
            The more I research the more confused Im getting about this investment into the house! Would appreciate any advice! Thank you!!

        • I installed my own system – Mr Cool (which is a rebranded Mitsubishi with full warranty). It was easy for someone with basic handyman skills and tools. For extras, I only bought a 4-inch hole saw, the permits and the post electrical inspection on the new circuit I ran. I have a 1,250 sq foot home upstairs with no duct work (boiler heat). I have a 24K unit cooling the main open floor plan and plan on installing smaller units in the bedroom later. For now it has cooled my entire house perfectly. These installers are making some serious margin for easy work. Seriously stupid easy work.

          • Ian,
            Good luck with that. If the system was not pressure tested and evacuated correctly you will soon have problems. Contractors who have been properly trained will agree with me

          • Ian,
            Nice and easy install. I’m getting one of the 12K units soon to DIY. Nice savings at $1000 compared to having one installed for $4000-$6000.

            From the MRCOOL website on their DIY model: *State certified or licensed HVAC contractor not required for warranty on the DIY series units.

          • Brian,
            I’ve read of guys doing it DYI and then just having a tech make the final connections and performing evacuation and pressure check. I get that contractors have overhead, but their installation costs seem excessive. Would I be wrong in presuming many installers are trying to offset the decreased labor costs from not installing a traditional system.

          • Sounds like Ian is a contractor who’s butt-hurt about not getting to over charge someone for a simple install. Good luck with THAT, Ian.

  169. I tend to agree, Frezz. I’m about to start construction on a new home. I’m seriously considering mini-split. But everything I read about them them seem too good to be true. So I wanted to find some reviews that were NOT so “glowing” and found this one.

    The refrigerant lines (at least in new construction) can be run in walls. Otherwise, lines and drainage hanging out on the wall is a fair criticism. I dont’ know if energy loss through the refrigerant lines can be equated to the same kind of air loss through leaky ducts but I would suspect that it’s much easier to “seal” mini-split refrigerant lines.

    Critique of “wall units” is certainly fair. We in the US are vain like that. But the systems also feature recessed ceiling mounted cassettes so that is not a fair critique. Plus, some of the wall units are of a sleek design and do not completely suck.

    The author writes, “you could still expect to spend about 50% less on a typical central AC system installation versus the more expensive ductless options.”

    I dunno about that. My new construction is about 1900 sq ft main level (“open” plan) and 900 basement. I know I can purchase “high dollar” 4 zone Mitsubishi mini-split for about 5 grand on-line. I do not know how much installation will be but let’s say $2000 for 7k total.

    According to my research, a whole house central AC with ducting will cost 15k or so. I THINK. I just don’t see how in the world a claim of central air cost “50% less” could be remotely true from what I’ve been reading online.

    And the energy savings through mini-split seem almost too good to be true but the SEER numbers don’t lie (too much).

    All this may change when I’m ready to request quotes from local AC people but I suspect Frank’s claims are way off with regards to cost. From what I’ve read, worst case is that mini-splits in new construction tend to cost “about the same” as central air.

    All that said, Frank, thanks for the critique. You certainly could be spot-on with your critiques as I am certainly not qualified to really “know” one way or another. I appreciate your contrary view as it will make me study the issue even more.

    • Agreed. I do not own a mini split or central a/c but im an hvac technician who has installed plenty of both. For a house with ducts, I would stick to central a/c. But for a house without ducts I feel the new dc inverter high SEER mini splits are a no brainer. This article seemed very one sided. Mini splits are more efficient, easier to install, and in terms of looks and installation there are many options including recessed ducts and artwork with hidden ducts.

      • You can avoid thermal loss by properly insulating the refrigerant lines: make sure its thick enough, sealed, clamped properly, and protected from the elements – particularly UV.

        The refrigerant lines probably come pre-insulated but you can add insulation over it. Proper insulation sizing depends on geography but it ranges from wall thickness of 3/4″ to 1 1/2″ thick.

        Any fastening of the line to the wall or other surface should be done in a way not to crush the insulation (which eliminates the thermal protection).

        Cover the properly insulated line with a paintable PVC cover to protect from elements – in particular UV. This also is more aesthetically pleasing.

        You want to minimize, if possible, the length of the refrigerant line that is exterior to the home.

        Ductless mini-splits, if installed and insulated properly, should have virtually zero energy loss through the refrigerant lines.

    • Jim, Mitsubishi requires contractors to be certified. If you buy the unit on line the warranty is void and for good reason. These system are more complex than you can imagine. No certified Mitsubishi dealer is going to install a unit for $2000. If they do you’ll probably get a tail light warranty. Once the tail lights go out then you’re on your own. And guess what… you call another Mitsubishi dealer and they will tell you they won’t touch it.

      • 2000 to install a mini split? Hmm, get better quotes. It is much easier to install that than a full a-coil system, even a diy job.

    • Jim, this is an old thread but people still showing up here for information. If you have not actually priced installation you’ll find that is not you’d logically think it should work. Basically, HVAC guys don’t want to install these mini splits and they will price them slightly higher than ducted system replacements. From everything I’ve been able to see they are trying to keep all the ducting creating equipment they have invested in usable. And as Austinairco.com above stated you can’t get the warranty, unless these guys install it and they won’t touch it if they didn’t install it. It’s such a scam and I hope Mitsubishi changes their mind on this practice and goes direct to consumer.

  170. Thanks for you feedback and information. I actually got some quotes for a ductless system with multiple evaps for my 2,600 sqft home a few years ago and the cost was a lot more than installing a convential ducted system. I have also spent consderable time in homes with ductless systems and I can say that I agree with most of what you are saying in your post. However, as I have researched this topic and surveyed many HVAC contractors, my conclusion is the ductless systems are great for certain applications and climates but they get to be pretty expensive for whole home applications especially when there is existing ductwork and there are some disadvantages too. There have also been recent advances in ducted HVAC technolgoy that I think makes the ducted solutions even more attractive now. Anyway, thanks again for your post. I agree with you that the ductless technology has some really nice features. We will continue to monitor the pros and cons of each type of system as the technology evolves.

  171. Frank, has obviously not installed one of these systems or been in a home with a properly set up system. Ductless mini splits offer inverter technology. Meaning the compressor can ramp up and down based on the demand load. A 2000 sqft house can easily be heated/cooled with a 4 head mini split heat pump. If certain zones aren’t calling for heat or cool the compressor will ramp down and use a fraction of its total output to satisfy the home.
    An inverter heat pump can effectively produce heat down to zero degrees Fahrenheit
    Each head consumes about 40 watts of power to drive the blower at high speed which is very minimal at 0.18 amps.
    A conventional forced air system consumes 4-5 amps of power to run the blower motor to push air through duct work, which in most homes is poorly deigned at best.

    • Why are mini split ductless systems still so expensive in the US. They cost a fraction of this in South America , for example!

      • This is a good question. We don’t claim to know exactly why manufacturers and distributors price products the way they do. However, in the case of mini-split, ductless systems it is important to note a few key differences between the US and other regions which might lead to some of the pricing differences you mention in your post. One difference is the minimum efficiency standards in the US are higher than most regions and in some developing countries there is virtually no minimum efficiency standard at all. While this regulation, which affects all unitary AC systems in the US, drives costs a little higher it also helps the US avoid adding more power plants each year to support electricity needs for grid reliability and also avoid some of the environmental problems which are common in other regions. Another difference is that in the US, all new systems must use newer, more environmentally friendly refrigerants and other, developing countries can still use the older, less expensive refrigerants. The other thing to keep in mind is that in the US, living spaces tend to be a little larger for most part. This means the units used here will often need to be larger and more powerful than the more popular models in other countires in order to provide proper cooling and dehumidification for larger, US style homes. I am not sure if this totally answers your question but these are a few reasons you might want to consider.

        • Having lived in the Caribbean where I worked as an HVACR tech as well as a buyer for a very large mechanical company, I can attest to the fact that our major manufacturers of HVAC equipment produce equipment specifically for export markets. The quality is not as high as it is for product sold in the domestic market. In some cases the equipment is not comparable whatsoever and has a very short life span, low reliability and high energy consumption characteristics.

          You ALWAYS get what you pay for.

        • Amen.
          And, Scandinavian countries are better regulated than the US, and duct systems are non existent, as with hot water tanks.
          The stupid installations in the photos are not what a professional would do. Brasil, Mexico contractors do a much better job, and have better knowledge about these systems than US HVAC contractors, because they have been using these here for dozens of years.
          My ac energy bill and usage are 1/3 of what I was paying in Indiana, and I have 6 minisplits in our 1450 s.f home in Cancun.
          It would be even better had we beter windows.

          • What a bunch of BS.
            Third world countries install mini splits bc the lack of qualified personnel.
            I spend a lot of money in my 3 condos in Panama, all the routing of the refrigerant lines full of condesation, costly job plus the repairing of the neighbors roof.. and yes, in the 3 condos, 3 different buildings,my upper floor neighbours had to the job also, extracting the long expensive copper ref, lines, draining the water, pplastering and the painting my roof.. Just to repeat the process in a couple of years. Of course you don’t have good windows, we don’t have here neither, those soundproof thermal efficient beauties belong to the first world!

      • They cost a fraction in Asia as well, where the vast majority of all home air conditioning systems are Ductless Mini Split systems.

    • I had a 3 ton (42000 BTU) 4 head system installed brand new for 3600.00 total! It was going to cost me 2400.00 just to redo my ductwork with the old package unit. My electric bill is just barely over half what it used to be and the house is comfortable everywhere. When the wife cooks, the bigger head senses the heat and it directs the air toward the kitchen. She is happy and I’m extremely happy with a happy wife and a much cheaper electric bill. By the way, we got a 900.00 discount for trading in the old unit and the power company sent us a 300.00 check for upgrading. And we are expecting a tax credit this year also. So without the tax credit, I basically got a new system with a 10 year warranty (7 years from manufacturer and 3 extra years from the utilities commission) for the same cost of simply redoing the ductwork. It’s a no- brainer!!

      • Would you happen to have a company to recommend for the install? Or a quote from them I could pass along? I’m very interested in adding a ductless system in my 1400 sq foot home as I don’t want to replace my old HVAC unit and Ductwork (the quotes I’m getting are like $16,000 on average). Thanks for any info you can give

        • Hi David – The policies for this site do not allow us to recommend particular brands or service providers. However, we do support ACCA – an industry group that has a site and a link to help you find qualified contractors in your area. http://www.acca.org/locator

          We also recommend getting 2-3 quotes for both types of equiment and the installation services. BTW, not sure why you would have to replace your ductwork if you get a new system – most people don’t replace ductwork unless it is really bad or leaking. Good luck!

          • Ductwork is designed for the system it is installed for. Even if folks opt not to replace it, they really should in most cases. Air flow is a very important component of central air design and calculations. Using the wrong duct can cause frozen evap coils, slugging of the compressor, hot and cold zones, compressor burnout, etc.

      • How did you get the mini split for so cheap? I had a contractor come & he gave me quote of $9,000 for a 4-head unit for a 1,200 soft house. I think the units alone go for about $4,000 online

      • Hello Michale,
        Can you tell me which company did that work? I am very interested to install the same system.

      • I would sure like to know more about that. I have a 3 floor, 1800 square foot vacation rental home on the North shore of Lake Tahoe. It has an older boiler hydronic heating system with radiators that has barely kept up in some cold winters. No air conditioning. There are maybe 20 days each summer when a/c would be really handy and it would be nice to have a way to supplement the boiler when it gets very cold. Also, with 3 floors sometimes it is too cold on the bottom floor or too hot on the top floor. The Mitsubishi system sounds great but is very expensive (if memory serves with 5 zones I was looking at at least $8,000.

        • Hi Trevor -Here are a few thoughts on your situation. First of all, it might be good to have a contractor check your boiler to make sure it is operating properly. There are some settings and adjustments that might be affecting its performance. If it is set up properly and still not keeling up, you might also try to add insulation or eliminate any air leaks within the heated space. If there are no obvious leaks and the boiler is sized properly then you might also try adding ceiling fans or some other air moving devices to get the warm air on the third floor to the cooler first floor. Once you have tried some of those ideas and you decide you need to add some heating capacity you could probably add some mini-split heat pumps to the space but the issue with this will be that you would need them on the first floor during the winter but on the third floor during the AC season. One other thought on adding these new units is that when you add capacity you will probably be adding energy costs if you run them at the same time as your boiler heat. However, the heat pumps can be very efficient in the fall and spring when you are not running your boiler heat. There are a few other posted comments at the end of this string which deal with the use of mini-splits with hot water, boiler heat so you might want to also read those before deciding. We also recommend getting 2-3 quotes from different contractors to make sure you have the right heating and cooling capacity to meet your needs. Good luck with your HVAC project.

          • Don’t most boiler systems gt set up for avg worst temp outside like 180 dgr or something? simply adding a temperature sensor outside to set the limit helps save fuel during spring and fall season’s. Could have sworn I seen this done on Ask This Old House.

            I haven’t seen anyone say anything about using a mini split for a garage for heat when Pipes might freeze. Something I’m thinking about doing. I did my HVAC system 3 years ago lowered my bill by 1/2 on a 23 year old system with standing pilot lite and seer 8 compressor. Its paid for it selfe in 2 years.
            My beef is Mim code when my house was built was garage ceilings had a r-9 Cold pushes heat, so cold air comes in my 16×7′ door from the leaks pushes on the r-10 wall then find the weak spot and makes the heat go out the r-45 attic above 2 bedrooms and a bathroom. My garage has not air ducts in it and I’m happy about that. however in the teens and below a bit of safe heat in the garage would help keep pipes from freezing and the rooms above warmer in my 2 story house. Its either a min split and or closed cell spray foam to stop air movement.

    • Can you mix different brands inside units with different outside units , say , LG inside with a Gruinaire outside and vise versa ??

      • Hi Richard – I have not heard of people mixing indoor and outdoor units with ductless mini-splits. You might want to get a few different contractors to advise you before trying it. You might also ask them specifically about the electronic controls and if they are compatible. Maybe one of the contractors who follow this site can help? Good luck with your HVAC project.

      • Nope, mini splits are system and model specific and the technology changes all the time.

        So if you’re going to replace a part of it you will most likely have to replace the whole thing each and every time.

    • I have seen 3 major problems over the years with mini splits

      1.how do you get 4 x 12000 btu heads outputing at 100% with a 36000 btu condenser? simple math. you dont

      2. how many years do you get out of a 200 cfm blower motor on your minisplit airhandler? not many.
      low cfm fans build up dust and even worse mold causing your motor to burn out quickly.

      3. Usually after 2 years the brand of mini split you’ve purchased, has folded. Ie. No parts available.

      mini splits are a step above a window shaker but do not compete with a proper ducted split system.

    • Frank, I hope three years later you have actually learned something. Thank goodness you stopped at four because your information is so far from correct.

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