R134a has similar thermodynamic properties to R12

Refrigerating capacity, energy demand, temperature properties and pressure levels are comparable, at least in air conditioning and medium temperature refrigeration plants. This refrigerant can therefore be used as an alternative for most former R12 applications.

For some applications R134a is even preferred as a substitute for R22, an important reason being the limitations to the use of R22 in new plants and for service. However, the lower volumetric refrigerating capacity of R134a (R134a/R22 – comparison of performance data) requires a larger compressor displacement than with R22. There are also limitations in the application with low evaporating temperatures to be considered.
Comprehensive tests have demonstrated, however, that the performance of R134a exceeds theoretical predictions over a wide range of compressor operating conditions. Temperature levels (discharge gas, oil) are even lower than with R12 and substantially lower than R22 values. There are thus many potential applications in air conditioning and medium temperature refrigeration plants as well as in heat pumps. Good heat transfer characteristics in evaporators and condensers (unlike zeotropic blends) favour an economical use.

R134a is also characterized by a comparably low GWP (1430). Therefore, in view of future restrictions (for example EU F-Gas Regulation), the use of this refrigerant will still be possible for quite some time. If required, systems can later be converted relatively easily to non-flammable (A1) HFO/HFC alternatives with a GWP of approx. 600 ("Low GWP" alternatives for HFC refrigerants).