An experimental evaluation of the greenhouse effect in the substitution of R134a with pure and mixed HFO in a domestic refrigerator

Due to the UE Regulation n. 517/2014 refrigerants with a GWP higher than 150 are not allowed from January 1, 2015 in new domestic refrigerators. Thus, a replacement for HFC134a is needed. In this paper attention is devoted to the evaluation of the environmental impact in terms of greenhouse effect of the substitution of HFC134a with low GWP, HFO refrigerant fluids. The greenhouse effect is accounted for by the experimental evaluation of the TEWI index (Total Equivalent Warming Impact) that takes into account both direct and indirect contributions to global warming. The refrigerant fluids that have been tested as a drop-in are: pure HFO1234yf, the mixture HFO1234yf/HFC134a (90/10 % in weight), pure HFO1234ze, the mixture HFO1234ze/HFC134a (90/10 % in weight). In particular, with the mixture HFC134a/HFO1234yf (10/90 % in weight) there is a reduction of the TEWI of -295% respect to HFC134a.