The HVACR industry has been debating how to handle replacing R-410A in comfort cooling equipment ever since the courts ruled in 2017 that the Environmental Protection Agency (EPA) did not have the authority to phase down HFCs. After that ruling, EPA promised to issue phasedown guidance regarding HFCs, but when that did not happen right away, many states started implementing their own HFC phasedown schedules. California has been the leader of this movement, proposing a GWP limit of 750 for all new stationary air conditioning systems (residential and commercial) starting Jan. 1, 2023. Other states like Colorado and New York are looking to adopt the Significant New Alternatives Policy (SNAP) program Rules 20 and 21 for a variety of end uses, including new centrifugal and positive displacement chillers, but are not currently pursuing unitary equipment.
In order to meet this deadline, OEMs started exploring lower-GWP alternatives to R-410A, and R-32 and R-454B are two of the refrigerants that several have chosen to use. (R-454B will be covered in a subsequent article.) However, both are A2L refrigerants, meaning that they are mildly flammable, and model codes do not allow their use in many types of cooling equipment. OEMs are hoping that changes to the code will allow its use in time to meet California’s deadline, which is not that far away.