Which class of synthetic greenhouse gases is commonly used as refrigerants?

The class of synthetic greenhouse gases commonly used as refrigerants is hydrofluorocarbons, or HFCs. These compounds contain hydrogen, fluorine, and carbon, and many have the physical properties needed to move heat in refrigerators and air-conditioning systems. R-134a, also known as 1,1,1,2-tetrafluoroethane, is a well-known HFC refrigerant.

HFCs became widely adopted as replacements for chlorofluorocarbons, or CFCs, after CFCs were found to damage the stratospheric ozone layer. HFCs do not significantly deplete ozone, but many have high global-warming potentials, so they are still environmentally important greenhouse gases.

The common mix-up is treating all fluorinated gases as interchangeable. Perfluorocarbons and sulfur hexafluoride are also powerful greenhouse gases, but they are not the standard answer for common refrigeration use. CFCs were historically important refrigerants, while HFCs became a major replacement technology. International agreements, including the Kigali Amendment to the Montreal Protocol, now encourage reductions in high-warming HFCs.