R134a
Also known as: HFC-134a, R-134a, tetrafluoroethane
Short definitionThe single-component HFC for above-zero applications. It is common in chillers, milk cooling and car air conditioning; with a GWP of 1,430 it is giving way to refrigerants such as R513A and R1234yf.
R134a is a pure fluid with no temperature glide, and its behaviour is easy to predict. Its pressure is low: about 2.9 bar absolute at 0 °C. It runs efficiently when evaporation is above −10 °C. It uses POE oil and is very sensitive to moisture; evacuation and the filter drier need care.
In cold room work R134a makes sense only in above-zero rooms and cabinets. Below −20 °C its capacity falls sharply, so it is not used for frozen storage. In a new project R513A (GWP 631) or R290 is usually considered instead. Existing systems keep running and service gas is available, but its price is rising.