Experimental performance comparison of R1234yf and R134a automobile air conditioning systems employing a variable capacity compressor

Abstract

The use of refrigerants from the hydrofluorocarbon family has been restricted due to their high global warming potential, and the manufacturers have been using R1234yf recently, a refrigerant from the hydrofluoroolefin family, as a substitute for R134a in mobile air conditioning (MAC) systems. In this study, a laboratory MAC system with a variable-capacity compressor was set up, and its comparative energetic and exergetic performance was evaluated for the cases of using R1234yf and R134a by changing the test conditions in a wide range. The results revealed that the system with R1234yf provided on average 13.7% less cooling duty and 12.8% less coefficient of performance based on the total power input relative to the system with R134a. Furthermore, the system with R1234yf destructed on average 18.9% more exergy per unit cooling duty. Excluding the condenser, the components of the R1234yf system destructed more exergy per unit cooling duty than those of the R134a one.