The EPA has mandated the phase-out of R-410A refrigerant in new residential HVAC systems due to its high Global Warming Potential. R-454B is the primary replacement. R-454B is an A2L (mildly flammable) refrigerant, requiring new leak detection sensors and updated installation practices.
The AIM Act and R-410A Phase-Out
Under the AIM Act, the EPA set strict limits on the production and import of hydrofluorocarbons (HFCs). R-410A has a high GWP (2088) and can no longer be used in new residential systems manufactured after January 1, 2025.
Enter R-454B (A2L)
R-454B offers a 78% reduction in GWP. However, it is classified as A2L, meaning it is mildly flammable. This is a massive shift for the HVAC industry, which is accustomed to the non-flammable A1 classification of R-410A.
Safety and Installation Changes
New systems using R-454B require integrated leak detection sensors. If a leak is detected, the system will automatically shut off the compressor and activate the blower fan to disperse the refrigerant, preventing dangerous pooling.
Impact on Existing Systems
You do not need to replace your existing R-410A system. R-410A will still be produced for servicing existing units, though its price will rise sharply as supply is choked off by the EPA quotas.