The U.S. Environmental Protection Agency (EPA) has granted new regulatory flexibility to retrofit stationary air conditioners with a refrigerant that is slated to be phased out for other cooling, refrigeration and foam blowing purposes. HFC-134a, a hydrofluorocarbon with global warming potential (GWP) 1,300 times greater than carbon dioxide, is rarely used in existing residential and commercial rooftop units, but a recent EPA ruling deems it a comparable environmental and human health risk to other refrigerants currently allowed for retrofits.
HVAC industry insiders affirm the EPA’s latest decision addresses a tiny fraction of the market so it isn’t as incongruous with concurrent initiatives to restrict high-GWP refrigerants as it may appear. Notably, HFC-134a is among refrigerants that will be disallowed in newly manufactured centrifugal and displacement chillers as of January 2024 and will be prohibited in the manufacture of household refrigerators/freezers or as a blowing agent even earlier next decade.
“R-134a is not the refrigerant of choice for residential/light commercial air conditioning applications, even for retrofits,” says Karim Amrane, senior vice president, regulatory and international policy, with the U.S. Air-Conditioning, Heating and Refrigeration Institute (AHRI). “The predominant refrigerant in this end use is R-410A.”
R-410A has a GWP of 2,088, but HFC-134a is not an interchangeable replacement. Rather, it owes its market share to its compatibility with the hydrochlorofluorocarbon (HCFC) refrigerant, R-22, which has a GWP of 1,760 and was used in a wide range of applications until the HCFC phase-out under the Montreal Protocol pushed it toward obsolescence.
Under the Montreal Protocol, the consumption of HCFCs in developed countries has been cut by more than 90 per cent since 1996, heading to a complete stoppage of production and/or imports in January 2020. After that, a marginal supply — 0.5 per cent of the 1996 volume of consumption — will be available until 2030 to service existing refrigeration and air conditioning equipment that’s still operational. Currently, the newest equipment that relies on HCFC-based refrigerants would have been manufactured in 2010, which is still an early stage in the lifecycle of a chiller, but much more advanced for split and packaged air conditioning systems that typically last 15 to 20 years.
“There are plenty of them out there, but they are rapidly starting to disappear,” observes Warren Heeley, president of the Heating, Refrigeration and Air Conditioning Institute (HRAI) of Canada.
Regulatory approach differs in Canada and the U.S.
Although the EPA’s new allowance for HFC-134a in retrofits of residential/light commercial air conditioning would theoretically open the way for U.S.-based equipment owners to convert systems that are now using R-22, the business case for a switchover from HCFCs to a high-GWP HFC is dubious. Canadian equipment owners already had leeway to do the same thing, but after seeing what’s happening with price trends for the shrinking supply of HCFCs, Heeley suggests they may be hesitant to switch to a substitute with a phase-down destiny.
Similarly, the impact analysis accompanying Canada’s December 2016 amendment to its Ozone-depleting Substances and Halocarbon Alternatives Regulations indicates that the government intends to leverage to market forces to deploy its strategy. “The domestic air-conditioning industry would not be subject to product-specific controls under the proposed amendments. However, it is expected the end-use would be affected by the proposed bulk phase-down, as the decrease in the availability of refrigerants using HFCs is expected to cause manufacturers to transition to alternatives,” it states.
Canada and the U.S. were both key sponsors of last year’s Kigali amendment to the Montreal Protocol, which sets targets for a phase-down in production and use of HFCs, but they are taking somewhat differing regulatory routes to deliver on their promises. Canada has established GWP thresholds for various categories of uses, which will be lowered on a phased scheduled. To begin, there is a prohibition on manufacture and import of chillers using HFC refrigerants with a GWP greater than 700.
In contrast, the U.S. identifies and allows or disallows specific products through the EPA’s Significant New Alternatives Policy (SNAP) program. Industry insiders hypothesize the EPA’s latest decision arises from an equipment manufacturer’s request.
“Generally, it would be a manufacturer of a niche product for which none of the other substitutes (acceptable refrigerants) make sense,” explains Mark Menzer, director of public affairs with the HVAC/refrigeration supplier and engineering firm, Danfoss. “EPA then evaluates the request and we can assume that they determined, on balance, that the use of higher GWP refrigerants was the better choice from the standpoint of the environment and human health.”
The July 21 ruling also lists R-458A, an HFC blend with a GWP of 1,650, as acceptable for retrofit of residential and light commercial air conditioners. In both cases, the EPA decision states “it does not pose greater overall environmental and human health risk than other available substitutes in the same end-use.”
Barbara Carss is editor-in-chief of Canadian Property Management.