Common Refrigerant Types and Uses: R-22 (Freon): Previously widely used in residential and commercial air conditioning, but being phased out due to environmental concerns. R-134A: A common hydrofluorocarbon (HFC) refrigerant used in automotive air conditioning and some refrigeration systems. R-410A (Puron): A more environmentally friendly alternative to R-22, used in newer air conditioning systems due to its better energy efficiency and lower ozone depletion potential. R-407C: Often used as a re