The Basics of Suction Accumulators in Home Heat Pump Systems


Originally published on December 10, 2013

In order to troubleshoot the components of a heat pump system, you must first understand them. Since much of North America has transitioned into the heating season, it’s perfect timing to review a component commonly found in residential heat pump systems: the suction accumulator.

What is a suction accumulator?

Suction accumulators are critical components of air-to-air and air-to-water heat pump systems.

What does a suction accumulator do?

Air-source heat pumps must maintain a delicate balance and proper control of liquid refrigerant under low ambient heating conditions to adequately provide cooling to the compressor, and avoid excessive refrigerant floodback. If liquid refrigerant is allowed to flood through the system and return to the compressor without being evaporated, it can cause damage to the compressor. Depending on the type of compressor, this damage could range from liquid slugging, loss of oil (in the compressor), or bearing washout.

To protect against floodbacks on systems vulnerable to liquid refrigerant damage such as heat pumps, the accumulator’s function is to intercept the liquid refrigerant before it can reach the compressor. When a coil defrost is required, the compressor is exposed to sudden surges of liquid that can create extreme stresses in the system. The accumulator can act as a receiver during the heating and defrost cycles when system imbalance or an overcharge from field service could result in excessive liquid refrigerant in the system.

The accumulator can store the refrigerant until needed and feed it back to the compressor at an acceptable rate. Major movements of refrigerant take place at the initiation and termination of a defrost cycle, and while it is not necessary or even desirable to stop this movement, it is essential that the rate at which the liquid refrigerant is fed back to the compressor be controlled. Along with this proper metering, the accumulator can effectively maintain the crankcase or bottom shell temperature at acceptable limits. A properly designed suction accumulator can provide excellent protection against both potential hazards.

What type or size of accumulator should be used?

This component should be located in the compressor suction line between the evaporator and the compressor. It needs to have a volume/capacity large enough to hold the maximum amount of liquid that might return to it, and must have provisions for a positive return of oil to the compressor.

The actual refrigerant holding capacity needed for a given accumulator is governed by the requirements of the particular application, and the accumulator should be selected to hold the maximum liquid floodback anticipated. Typical accumulators manufactured for air conditioning or commercial usage have oil return orifices in size from .0625 to .125 inch diameter. The smaller orifice undoubtedly is more vulnerable to restriction from solder particles or other foreign material in the system, and an inlet screen would be advisable, particularly on systems with field-installed piping. Care should also be taken to prevent solder and flux from entering the accumulator, since excessive foreign material could plug the metering orifice, effectively trapping the compressor oil in the accumulator.

Suction AccumulatorsNote the refrigerant inlet is offset from the top of the J tube. As the refrigerant and oil enter the vessel, velocity separation takes place and the refrigerant expands due to the ambient temperature providing a heat source. At this point, the oil entering, (along with any liquid refrigerant) separates from the vapor refrigerant and falls to the bottom. The vapor refrigerant moves through the “J” tube as the compressor causes a pressure difference on between the inlet and outlet of the accumulator. As the refrigerant travels through the “J” tube, this causes a Venturi effect to take place across the orifice, drawing in oil from the bottom of the vessel. The vapor refrigerant carries the oil back to the compressor at a controlled rate.

 


Read Next: The Contractor’s Guide to Repairing or Replacing Flood-Damaged HVAC Systems

HVAC Flood Damage

Share
print
Was this helpful?
Vote This Post Up 14 Loading...

8 thoughts on “The Basics of Suction Accumulators in Home Heat Pump Systems

  1. Clinic olecranon bursitis mayo, furabid buy payment california

    Our professional pharmacists are ready to answer your questions!

    [url=http://cheapestpricesale.info/view/go/f02fba00/furabid][b]CLICK HERE To Order Furabid Without A Doctor Prescription Online[/b][/url]

    We sell medications at their cost price only without any additional fees! Try it out now!

    [b]Are there side effects to nitrofurantoin?[/b] These common side effects of nitrofurantoin happen in more than 1 in 100 people. Keep taking the medicine, but talk to your doctor if these side effects bother you or don’t go away: feeling sick (nausea) being sick (vomiting) and diarrhoea.
    [b]Can I open a amoxicillin capsule?[/b] You can take the amoxicillin capsule, tablet, chewable tablet, or suspension with or without food. You should take amoxicillin extended-release tablets within 1 hour of finishing a meal. Don’t crush, cut, or chew the extended-release tablets. You can crush, cut, or chew the regular or chewable tablets.
    [b]What is the strongest antibiotic for urinary tract infections?[/b] The following oral antibiotics are commonly used to treat most UTI infections (acute cystitis): Sulfamethoxazole-trimethoprim (Bactrim DS, Septra DS, others) Nitrofurantoin (Macrobid, Macrodantin) Fosfomycin (Monurol) Amoxicillin/clavulanate (Augmentin) Certain cephalosporins like cefpodoxime, cefdinir, or cefaclor.
    [b]Can I take amoxicillin if allergic to penicillin?[/b] No, you should not take amoxicillin if you are allergic to penicillin. Amoxicillin belongs to the Penicillin class of antibiotics and must be avoided.
    [b]Is Cefuroxime a strong antibiotic?[/b] Cefuroxime is a cephalosporin (SEF a low spor in) antibiotic. It works by fighting bacteria in your body. Cefuroxime is used to treat many kinds of bacterial infections, including severe or life-threatening forms. Cefuroxime may also be used for purposes not listed in this medication guide.
    Was his demise brought on by a frenzy of passion with the woman who had been his muse for so long? Or was the story no more than scandalous Victorian tittle-tattle? Ray Liottawas spotted engaging in a rigorous, socially-distanced workout at Gold’s Gym in Venice, CA on Saturday afternoon. Ray was joined by his trainer in the gym”s vast parking lot. Earlier this week, I was one of three furabid intrepid amateurs given a masterclass by one of this country’s supreme athletes, Saracens and England lock Maro Itoje. The results were predictably horrific. Make memories out of the dishes youre making now, whether thats a macaroni salad, baby back ribs or a potato chip omelet. After the video surfaced, fans dug up one of her songs believed to be from 2015, entitled Dindu Nuffin, a racist term used by the alt-right in reference to victims of police brutality. furabid Janet Ellis did what many people dream of doing while on holiday she stopped to have a ‘what if’ browse in an estate agent’s window and came home having bought a cottage For all the high-minded talk among techies, their new favorite app is an invite-only furabid (so far) social network for mingling with one another. Glaucoma kenneth schwartz. When you borrow, low interest rates are fabulous. But if you furabid need to live on your savings, you will be receiving far less income. President Trump enjoyed a leisurely start to Memorial Day weekend as he arrived at his Trump National Golf Club in Virginia Saturday for a round on the course. A festival In Kazanlak, Bulgaria, in June will celebrate the Damask rose grown in the country. A woman has shared how to cook delicious cheese and bacon pull apart rolls in a slow cooker instead of the oven. The recipe itself it easy to follow and takes two hours to cook high. RIATH AL-SAMARRAI IN DOHA The 17th athletics World Championships were held this week in Doha with plenty of drama on and off the track at the Khalifa International Stadium. While we sympathise with Boris for his undoubted ordeal, in undergoing the illness he has done so much to fight against, we must still urge him, in the friendliest possible way, to get a grip. An app offering short-term rentals called Globe says demand is way up. Resources for people in forbearance or struggling to make their payments. Gaza reports its first coronavirus death. New York is allowing gatherings of up to 10. When Covid-19 struck Washington State and the greater Seattle area locked down furabid to mitigate the spread, Zeeks Pizza saw 60% of its business evaporate. The reality star, 22, looked glam as she sat in the backside of her luxury car in a leather tube top and butterfly choker necklace. Kylie posted the image onto her Instagram account on Saturday. A trooper stopping a car with a suspected “impaired driver” on a U.S. highway on Monday was bemused to find a 5-year-old in the driver’s seat, the Utah Highway Patrol tweeted. Furabid man kaufen. Ruth Poniarsky, 64, from New York, revealed how taking the anaesthetic PCP at university led to a series of nervous breakdowns throughout her life. Lonely Planet’s Best in Europe is compiled annually by the travel company’s European experts to reveal their pick of the most exciting and underrated destinations to visit across the furabid continent. This Orpheus And Eurydice is the first of four Orpheus-themed operas running at the Coliseum this autumn, in which English National Opera is taking formidable artistic and financial risks.

  2. Just wondering why you didn’t mention the Tranes with the built-in the compressor.
    Thanks,
    J
    https://aceheatingandcoolingtn.com

    • Hi Leslie,

      Due to the outdoor ambient air in Winter being potentially below 32F, heatpump systems have a defrost cycle, A/C systems do not. Major movements of refrigerant take place at the initiation and termination of a defrost cycle, and while it is not necessary or even desirable to stop this movement, it is essential that the rate at which the liquid refrigerant is fed back to the compressor be controlled, to prevent damage to the compressor.

      Thanks,
      Scott

  3. hello,
    this is ujjwal singh from center for energy and environment research facility,india
    i have developed an instrument which can tell total amount of refrigerant(component wise) in terms of kg and fraction using sat/super heat temperatures.
    but i am not able to predict the amount gathering in accumulator.
    i need to design a new accumulator with glass tube level indicator.
    how can i calculate size of accumulator?

    • Hi Singh,

      Selection and sizing of a suction line accumulator is dependent upon whether it is intended as a field replacement or for a new application. The most common reason for field replacement of an accumulator is corrosive rust through. Since an accumulator is colder than atmosphere, it is subject to constant condensation and therefore corrosion.

      When replacing a suction line accumulator in the field, it is important that the selection is sized as closely to the one being removed as possible. Accumulators are sized by the OEM design engineer for their specific application. There is considerable testing and trial and error that goes into selecting the size and orifice for OEM systems. For field replacement, size the unit to match the exact diameter and similar length of the unit currently installed.

      OEM selection of the accumulator is based upon system testing and generally some selection criteria. The accumulator manufacturer provides capacity tables listing the holding capacity and flow capacity for each accumulator. The accumulator holding capacity should be sized to hold 50% or more of the total system charge. The accumulator maximum flow capacity in tons should not exceed a pressure drop equivalent to 1°F for the refrigerant. The minimum flow capacity in tons must be no less than 15% of the stated capacity in order to ensure a positive oil return. Refer to the suction line accumulator manufacturer’s literature and capacity tables for additional technical information.

      Thanks,
      Scott

Let us know your thoughts

Your email address will not be published. Required fields are marked *