What is a common refrigerant used in modern refrigeration systems?

R-134a is a common refrigerant used in modern refrigeration systems due to its effectiveness and environmental considerations. This refrigerant is a hydrofluorocarbon (HFC) that was introduced as a replacement for older refrigerants that were found to be harmful to the ozone layer. Unlike R-12, which is a chlorofluorocarbon (CFC) and is now banned in many countries due to its ozone-depleting potential, R-134a has a much lower impact on ozone depletion.

Additionally, R-134a has been widely adopted in automotive air conditioning and commercial refrigeration applications, making it highly prevalent in the industry. It offers good thermodynamic properties and is non-toxic and non-flammable, enhancing its safety profile compared to some alternatives.

While R-22 was commonly used in many residential and commercial systems, it is being phased out because of its high ozone-depleting potential as a hydrochlorofluorocarbon (HCFC). R-123, though useful in certain applications, is primarily used in chillers and has its own environmental concerns. Thus, R-134a stands out as the favored choice in modern systems for combining efficiency, safety, and minimal environmental impact.