Difluoromethane

Difluoromethane, also called HFC-32 or R-32, is a chemical compound with the formula CH₂F₂. It is a colorless gas used to cool buildings and vehicles. Because it is a type of hydrofluorocarbon, its use is being reduced in some places to help protect the environment. It is important to manage it carefully to keep the air safe.

Synthesis

Difluoromethane is made when dichloromethane mixes with hydrogen fluoride. A special helper called SbF₅ helps the reaction go faster.

CH₂Cl₂ + 2 HF → CH₂F₂ + 2 HCl

Applications

Difluoromethane is used as a refrigerant. It helps move heat and manage pressure in cooling and warming.

It is used in home and business air-conditioners in Japan, China, and India, replacing another refrigerant called R-410A. Because it can catch fire easily, it is used in special equipment with smaller amounts of the gas. Tests show it moves heat better than R-410A but needs more force to move the gas.

Besides cooling, difluoromethane is also used to push things out of aerosol cans and to make things puff up during production.

Environmental effects

Difluoromethane, also called HFC-32, can warm the planet. It has a global warming potential of 677 over 100 years. This is better than some older refrigerants, but scientists are still looking for even better options.

This gas is not restricted under the United States Clean Air Act because it does not harm the ozone layer.

European Union phase-out

The European Union made a rule to cut down on gases that heat up the Earth. Because of this, they are stopping the use of some coolants, including R-32, in homes. Starting January 1, 2026, you won’t be able to buy R-32 for regular fridges. For air conditioners and heat pumps, the rule will start between 2027 and 2030, depending on the size and type.

People are looking for new coolants to use instead. One option is R-290, but it can catch fire easily, so it’s not good for many homes. Another choice is R-454C, a mix of two gases, but it doesn’t work as well. A third option is R-744, made from carbon dioxide, but it’s too expensive for most homes right now.