Which of the following refrigerants is classified as an HCFC?

R-22 is classified as an HCFC, or hydrochlorofluorocarbon. HCFCs are a group of refrigerants that contain hydrogen, chlorine, fluorine, and carbon. R-22 specifically is known for its effective cooling properties and has been widely used in residential air conditioning systems.

This classification is significant because HCFCs are considered less harmful to the ozone layer compared to earlier refrigerants, such as CFCs (chlorofluorocarbons), but they still have some ozone-depleting potential. Regulations are gradually phasing out HCFCs in many countries due to their environmental impact.

The other refrigerants mentioned do not fall under the HCFC category. R-11 and R-12 are CFCs, which are more damaging to the ozone layer and have been largely phased out. R-134a, on the other hand, is classified as an HFC (hydrofluorocarbon), which does not contain chlorine and has negligible ozone depletion potential, but it is also a greenhouse gas contributing to climate change. Understanding the classification and environmental impact of these refrigerants is crucial in the field of HVAC (heating, ventilation, and air conditioning) management.