Air conditioners,refrigerators and freezers rely on the circulation of a refrigerant--a chemical that can efficiently remove heat from the surroundings as it repeatedly cycles between the liquid and gaseous states. R22 refrigerant belongs to a class of chemicals called hydrochlorofluorocarbons that are being phased out because oftheir ozone-depleting effects. R134a refrigerant is an alternative that contains no chlorine and hence no ozone depletion potential. It's a greenhouse gas,though, and it doesn't work as well as R22.
R22 is an HCFC, While R134a is an HFC
Like R12, which is the original Ozone Depleting Substances, R22 is marketed under our brand name Flyer, and it's one of the earliest CFC alternatives. Its chemical name is chlorodifluoromethane, and while it isn't technically one of the CFCs banned by the Montreal Protocol, it belongs to a closely related class known as hydrochloroflurocarbons (HCFCs). These refrigerants also contain chlorine that can potentially find its way into the upper atmosphere. HCFCs like R22 are being phased out of production and will be all illeagal in 2020.
R134a belongs to another class of CFC alternatives, called hydrofluorocarbons (HFCs), that don't contain chlorine.Its chemical name is tetrafluoroethane. It isn't the only CFC alternative on the market, and it isn't the best. HFCs may not be ozone depleting gases, butthey contribute to global warming, and R134a has more global warming potential than other HFCs, such as R152a. This fact has led the European Union to ban new R134a from use in new vehicles. The ban became effective in 2011.
Using R134a in Air Conditoner Systems Designed for R22
If you have a household or auto airconditioner designed to work with R22 refrigerant, and the system needs a recharge, a number of issues prevent the direct substitution of R134a. For one,the cooling capacity of R134a is only 60 percent that of R22, so the system condenser has to work overtime to produce the same amount of cooling. Here are some other issues: