California Tackles Climate Change by Adopting R32 for Air Conditioning

As the impacts of climate change become ever more apparent across the globe, the race is on to reduce greenhouse gas emissions from every possible source. In California, a major focus is on curbing the climate impact from refrigerants used in air conditioning and refrigeration equipment. By taking the lead in transitioning to next-generation refrigerants like R32, California is charting a path forward for reducing these harmful emissions.

The Potent Climate Impact of Refrigerants While carbon dioxide gets the most attention as a greenhouse gas, hydrofluorocarbon (HFC) refrigerants like R-410A that are used in air conditioning and refrigeration systems can be even more potent contributors to global warming. Over a 100-year timeframe, R-410A has a global warming potential (GWP) of 2,088, meaning it traps 2,088 times more heat than carbon dioxide on a pound-for-pound basis.

These refrigerants can leak from air conditioning and refrigeration systems during operation, maintenance, or improper disposal at the end of the equipment life. Even small leaks can have an outsized climate impact given the extremely high GWP of traditional HFC refrigerants. It's estimated that the emissions of HFC refrigerants like R-410A cancel out much of the energy efficiency gains from modern cooling equipment.

The Path Forward: Low GWP Refrigerants To tackle this source of greenhouse gas emissions, the Environmental Protection Agency (EPA) and partners like the Air-Conditioning, Heating and Refrigeration Institute (AHRI) have been evaluating and approving new low global warming potential (low GWP) refrigerants through the Significant New Alternatives Policy (SNAP) program. The goal is to find viable alternatives to traditional high-GWP HFC refrigerants used in a variety of cooling applications.

One of the most promising low-GWP refrigerants is R32 (difluoromethane), which the EPA approved through the SNAP program in 2015. With a GWP of just 675 over a 100-year timeframe, R32 represents a roughly 68% reduction in global warming impact compared to the R-410A refrigerant it is designed to replace in air conditioning systems. At the same time, R32 provides similar or even slightly better energy efficiency properties compared to R-410A.

California Leads on Adopting R32 Given these environmental benefits of R32 as well as its affordable cost and relative ease of adoption, the California Air Resources Board (CARB) has put regulations in place to drive the rapid adoption of this low-GWP refrigerant for air conditioning uses. The first regulation, which took effect on January 1, 2023, prohibits the use of high-GWP refrigerants like R-410A in new residential and commercial air conditioning equipment under 65,000 BTU/hr of cooling capacity.

To comply with this regulation, air conditioning manufacturers have been redesigning and testing systems to use the approved low-GWP alternative refrigerants like R32. This required minor changes like using different materials and adjusting the refrigerant charge amount, but modern R32 air conditioning units are essentially similar to previous R-410A versions in terms of capacity, efficiency, and installation requirements.

While R32 is mildly flammable and classified as an A2L refrigerant by safety standards, it is still considered safe for use in air conditioning equipment when following proper building codes, technician training, and labeling requirements. Millions of R32 air conditioning units have already been safely installed in commercial spaces and homes across Europe and parts of Asia since this refrigerant started being adopted abroad in the mid-2010s.

The industry rollout of R32 air conditioning equipment has progressed relatively smoothly in California in 2023, though education on the new refrigerant has been an ongoing process for manufacturers, contractors, and homeowners. Residential customers in the state will increasingly encounter R32 as the standard refrigerant when replacing or installing a new home air conditioning system under 65,000 BTU/hr of cooling capacity.

California's regulations are also driving the adoption of R32 and other low-GWP refrigerants in commercial air conditioning equipment under 65,000 BTU/hr of cooling capacity, which will be required by January 1, 2025. This includes packaged rooftop units, VRF multi-split systems, and other light commercial air conditioning applications. Some manufacturers have already started introducing R32-based commercial products to meet this future compliance date in California.