In 1987, an international treaty called the “Montreal Protocol” was established to protect the atmospheric ozone layer from the harmful effects of certain manufactured chemicals. Now, over 25 years later, we are in the midst of the forced phase out of R-22 (an HCFC), one of the restricted chemicals commonly used as an air conditioning refrigerant. The transition of the U.S. air conditioning industry from R-22 to R-410A has actually been going on for about ten years as the first R-410A systems were introduced in the mid 1990’s. We are now in the final stages of this transition, which includes the painful effects of shortages and high prices for replacement refrigerant, and confusion over various retrofit application challenges. As our industry completes this transition it is important to know there might be another refrigerant change on the horizon and we might not get 25 years to get ready for it like we did with the last one.
The next refrigerant transition we are anticipating will be driven by government regulating authorities’ desire to address concerns about “global climate change” or “global warming”. While R-410A is better for atmospheric ozone, scientists have determined that lower global warming potential (GWP) refrigerants are desirable to address potential long term climate impact. So, the industry is busy working on several new refrigerants with lower global warming potential in advance of anticipated regulations in this area. This article will provide some background information on how this is progressing and what you might expect to see over the next few years.
Here are four things to keep in mind as you hear about these possible new refrigerant transitions and conversions.
- There is probably not going to be just one new refrigerant adopted in every region of the world at the same time.Just like the R-410A conversion, the adoption of new, low GWP refrigerants will be driven by the particular regulations in those regions and the application needs involved. For example, many developing regions, including China, are still allowed to use R-22. So, if a new low GWP refrigerant becomes available to them they might go straight to the new refrigerant and skip using R-410A altogether. Just as happens today, some applications will require different refrigerants which are optimized for certain operating conditions. As we move through another refrigerant conversion you can also expect to keep the old refrigerants around and add the new ones over time as regulations dictate.
- The total global warming potential includes both the direct and indirect effects. The direct effects are from refrigerant which ends up leaking into the atmosphere and the indirect effect from the GWP caused by the amount and source of the energy required to operate systems with the new refrigerant. In many cases, the magnitude of indirect GWP outweighs the reduced direct GWP benefits of the new refrigerant. For example, in some refrigeration applications, CO2 has been considered in various configurations even though it is not particularly energy efficient or cost effective in some of these applications. However, there is still some interest for its use in the US due to its very low direct GWP characteristic. Certain regions in Europe which are using very low GWP power sources (hydro, nuclear, wind, etc.) actually seem to only consider direct GWP effects since the indirect GWP from low efficiency is minimal – even though the equipment costs are high.
- Increased flammability might become an issue for some of the new refrigerant alternatives. Many of the alternatives being considered for U.S. air conditioning may have an “A2L” rating which means the refrigerant will burn if exposed to an open flame but will not continue burning when the flame is removed. This is in contrast to some regions of the world which have been using hydrocarbons (like propane) as the refrigerant in small charge systems in an effort to reduce the direct GWP of their systems. Hydrocarbons have much higher flammability than A2L and will ignite if exposed to a flame so it is doubtful HC’s would ever be considered in typical U.S. air conditioning systems. However, A2L refrigerants are being considered by some manufacturers in the U.S. In any case, if any new refrigerant has increased flammability relative to our current refrigerants, extra care will be needed to deal with this factor in the system designs, applications, and maintenance procedures which use these new refrigerants.
- This process will take a few years to figure out. In addition to all the engineering design considerations required to consider the new refrigerants there are also many commercial and legal issues to resolve. As we were developing some of our existing refrigerants like R-410A, the ownership and licensing of the intellectual property rights for the new refrigerants was sorted out by the various chemical companies and system OEM’s in parallel with their product development efforts. We are hopeful that a similar process will take place with the low GWP refrigerants to insure adequate supply and reasonable costs for the new refrigerants. The chemical companies, system OEM’s and component suppliers all need to work together on these alternatives to develop viable options in advance of any new regulations.
As the U.S. HVAC industry has done in the past, many companies are actively supporting AHRI’s AREP (Alternative Refrigerants Evaluation Program) investigations into the several alternative refrigerants. Emerson is also working with industry groups like AHRI, NATE, ASHRAE and ACCA who also facilitate the flow of industry information. We are working directly with the chemical manufacturers, our OEM customers and large groups of contractors, to make sure we are ready with compressors to support any direction the industry decides to go. Emerson is currently considering several viable low GWP refrigerants and we are not actively promoting any one refrigerant path for U.S. air conditioning at this time.
The following are some links to recent articles on this subject which might be of interest.
Contracting Business, February 11, 2013
ACR News, December 6, 2012
New York Times, November 22, 2012
Reuters, November 7, 2012