The federal AIM Act, which will phase down HFC refrigerants 85% by 2036, was designed to encourage a safe transition to lower-GWP refrigerants such as R-32 and R-454B in comfort cooling equipment. However, these alternatives to R-410A are mildly flammable (A2L) and thus require updated building codes and standards to ensure their safe use.
The applicable safety standards from ASHRAE and UL have been updated, but most state building codes do not currently allow the installation of stationary comfort cooling equipment that contains A2Ls. There are several exceptions, including Florida, Oregon, North Carolina, and Washington. These states have already updated their building codes to allow the use of A2L refrigerants in larger air conditioners and heat pumps, and several more states are looking to do the same — possibly later this year.