Which refrigerant was commonly used prior to the phase-out of CFCs?

Freon, specifically R-12, was widely utilized in refrigeration and air conditioning systems before the significant phase-out of chlorofluorocarbons (CFCs) due to their detrimental effects on the ozone layer. R-12 became prevalent because it was effective, stable, and non-flammable, making it an attractive choice for many applications.

The move away from CFCs stemmed from their contribution to ozone depletion, which led to international agreements such as the Montreal Protocol aimed at reducing and eventually eliminating these substances. As a result, the use of R-12 was curtailed and replaced with other refrigerants that have a lower impact on the ozone layer.

In contrast, R-22 is a hydrochlorofluorocarbon (HCFC) that was introduced as a transitional refrigerant because it has a lesser ozone depletion potential compared to R-12, but it is also being phased out. R-410A is a hydrofluorocarbon (HFC) that does not deplete the ozone layer and is used as a substitute for R-22 in newer systems. Ammonia (R-717) is a more traditional refrigerant often found in industrial applications and has different properties and environmental concerns compared to C