What kind of freon goes in a home air conditioner?

The type of refrigerant used in an air conditioner depends on the the age of the system. If your AC system was built before 2010, it most likely runs on R-22 (Freon) refrigerant. However, since January 2020, Freon is no longer manufactured or imported. R-22 was found to be ozone-depleting, leading to the phase-out and replacement with the eco-friendlier R-410A.