Refrigerant R-134a, also known HFC-134a, is a hydrofluorocarbon (HFC) refrigerant. HFO-1234yf is a hydrofluoro-olefin (HFO) refrigerant.
Both types of refrigerants are composed of hydrogen, fluorine and carbon atoms. However, with HFC refrigerants, the atoms are connected by single bonds between the atoms, whereas the atoms in HFO refrigerants at least one double bond between the carbon atoms.
While HFC-134a has been one of the global standard automotive air conditioning refrigerants, it will not meet the European Union’s Mobile Air Conditioning (MAC) Directive that reduces the climate impact of air conditioning in cars sold in the EU.
HFO-1234yf, which has physical properties similar to R-134a, complies with the directive because of its low Global Warming Potential (GWP) and has the potential for direct substitution of into existing R0134a automotive air conditioning systems with minimal modification.