Experimental study on the operating characteristics of a display refrigerator phasing out R134a to R1234ze(E) and its binary blends

In recent years, the refrigerant drop-in replacement of R134a has been mainly motivated due to environmental issues. This study aims to experimentally compare the operating characteristics in light commercial refrigeration using a display refrigerator when R134a is substituted with pure R1234ze(E) and R1234ze(E)-R134a blends. The refrigerants R450A (R1234ze(E)-R134a 58-42wt% blend), and R1234ze(E)-R134a 90-10wt% blend with GWP of 547 and 150 respectively are evaluated. The adequate refrigerant charge is determined, and the performance evaluation is carried on under controlled ambient temperatures of 24, 32, and 40 degrees C. The results show a slightly reduced refrigerant charge for higher operating temperatures. Pure R1234ze(E) and its mixtures with R134a are a suitable short-term solution in light commercial refrigeration, satisfying ambient regulations with the maximum electric energy input increase by 6% under ambient temperature of 40 degrees C. Its reduced operating pressure of 36% at the condenser might result of interest for some applications.