A brief performance comparison of R1234yf and R134a in a bench tester for automobile applications

Performance of R1234yf and R134a is examined in a heat pump bench tester under the conditions for mobile air-conditioners (MACs). Though HFC134a have been used predominantly in MACs for the past decade, it must be phased out from 2011 in new MACs in Europe due to its high global warming potential. To solve this problem, ‘drop-in’ tests are carried out under summer and winter conditions with R1234yf and HFC134a in a bench tester equipped with an open type compressor for MACs. Test results show that the coefficient of performance and capacity of R1234yf are up to 2.7% and 4.0% lower than those of HFC134a, respectively. The compressor discharge temperature and amount of charge of R1234yf are 6.5 °C and 10% lower than those of HFC134a. Based upon the results, it is concluded that R1234yf can be used as a long term environmentally friendly solution in MACs due to its excellent environmental properties with acceptable performance.