There are several refrigerants group of HCFCs, HFCs, HCs (Hydrocarbons). It is generally called as ASHRAE designated numbers such as R22, R32, R134a, R152a, R410A, R404A, R407C, R507C, R600a (Isobutane), R290 (Propane), R717 (Anhydrous Ammonia), etc.