Refrigerant, also known as refrigerant working medium, is the working medium of the refrigeration cycle. It uses the phase change of refrigerant to transfer heat, which not only absorbs heat when vaporizing in the evaporator but also releases heat when condensing in the condenser.

　　Air conditioners and refrigerators bring great convenience to people's daily life, and at the same time improve the comfort of people's life. However, the refrigerants they use have brought great harm to the industry. First, the Cl in the refrigerants has sustained damage to the ozone layer, and second, their greenhouse effect potential.

　　At present, air conditioners mainly use two kinds of refrigerants, one is Freon R22, which is definitely to be eliminated and has strong destructive power on the atmospheric ozone layer. Another kind of freon R410A, a new type of environmental protection refrigerant in the world, has no damage to the ozone layer.

　　Freon R22, difluorochloromethane with the molecular formula of CHCLF2; That is, the freon that we usually refer to as destroying the ozone layer. It can also be used as an aerosol spray for killing granules and painting and is the basic raw material for producing various fluorine-containing polymer compounds. However, R22 belongs to HCFC refrigerant, and its use will be restricted and prohibited because of its strong damage to the ozone layer in the atmosphere.

　　Freon R410A, a mixed refrigerant, is a mixture of Freon R32 (difluoromethane) and Freon R125 (pentafluoroethane), which is harmless to ozone. It is what we usually call a "fluorine-free" refrigerant, but it contains fluorine.

　　But Refrigerant R410 is not perfect. It is a greenhouse gas, and its greenhouse effect is far greater than that of carbon dioxide, even exceeding R22. Therefore, the industry generally believes that R410A is only a transitional product, not the final solution.