Experimental drop-in replacement of R404A for warm countries using the low GWP mixtures R454C and R455A.

This article presents an analysis of the feasibility of R454C and R455A, two new low global warming potential (GWP of 148) refrigerants, in vapor compression refrigeration systems as alternatives to R404A for warm countries. R454C and R455A can be the most viable low GWP options to perform a direct replacement of R404A because of the similar characteristics. They only present meaningful differences in flammability, critical temperature, temperature glide and vapor density. The analysis is based on an experimental comparison of R404A with R454C and R455A, using a fully instrumented experimental setup equipped with Internal Heat Exchanger (IHX) at condensation temperatures that represent operating conditions of warm countries. The experimental results show that cooling capacity of the replacements is slightly lower than R404A, being the Coefficient of Performance (COP) of the new mixtures 10–15% higher than that of R404A, especially at higher condensation temperatures. The results also show that the adoption of an IHX is not recommended with the alternatives due to the discharge temperature increase and the low energy performance benefit. [ABSTRACT FROM AUTHOR]