VATIS UPDATE Article

Bitzer, Germany, has announced the approval of the HFO refrigerants R1234yf and R1234ze(E) and blends R513A and R450A for use in its CSH and CSW screw compressors. Bitzer points out that the two HFO alternatives to R134a have global warming potential (GWP) of under ten, and the non-flammable HFO/HFC blends GWPs of about 600. The volumetric refrigerating capacity and pressure levels of R1234yf are described as comparable with those of R134a, while the capacity figures and pressure levels of R1234ze(E) are around 20 to 25% lower.

According to Bitzer, it subjected R1234yf and R1234ze(E) to intensive testing, and the compressors performed well with both in all of the tests and laboratory experiments. The tested compressors achieved nearly identical isentropic efficiency values with R1234yf and R1234ze(E) as with R134a. Due to differences in the thermodynamic properties, the COP measurement results are in some cases slightly lower.