A refrigerant is a chemical compound that cycles through an air conditioner or heat pump, absorbing heat indoors and releasing it outdoors. It works by changing between liquid and gas states inside the system's coils. As liquid refrigerant passes through the indoor evaporator coil, it absorbs heat from room air and evaporates into a gas. The compressor pressurizes that gas, raising its temperature, and the outdoor condenser coil releases the collected heat as the refrigerant condenses back into liquid. This loop repeats continuously while the system runs.
Common Residential Refrigerants
Refrigerant |
GWP |
Status in the US |
R-22 (Freon) |
1,810 |
Production and import banned since January 2020. Depletes the ozone layer. Only reclaimed stock is legal for servicing. |
R-410A (Puron) |
2,088 |
Manufacturing of new equipment stopped January 2025. No ozone harm, but high greenhouse impact. Existing systems can still be serviced. |
R-454B |
466 |
Replacing R-410A in ducted systems from Carrier, Trane, Lennox, and Rheem. Classified A2L (mildly flammable). |
R-32 |
675 |
Replacing R-410A in ductless systems from Daikin, Mitsubishi, and LG. Classified A2L. |
GWP stands for Global Warming Potential, scored against CO2 at GWP 1. The EPA's AIM Act requires an 85% reduction in HFC consumption by 2036 relative to 2011-2013 levels, which is driving the shift from R-410A to lower-GWP replacements.
Why Refrigerants Are Not Interchangeable
Each system is engineered around one specific refrigerant. R-410A operates at roughly 50% higher pressure than R-22, so an older R-22 unit cannot accept R-410A without destroying its components. The same constraint applies going forward: R-454B and R-32 each have different pressure profiles, flammability characteristics, and lubricant oil requirements than R-410A. Changing refrigerant types typically means replacing the outdoor unit, indoor coil, and refrigerant lines, which is why a refrigerant transition usually results in a full system replacement rather than a parts swap.
For anyone still running an R-22 system, reclaimed refrigerant is the only legal supply. Prices have climbed steeply since the 2020 production ban, and the cost of a single recharge now sometimes rivals the down payment on a replacement system running a current refrigerant.