Change in energy performance as a result of a R422D retrofit: an experimental analysis for a vapor compression refrigeration plant for a walk-in cooler.

In this paper, the energy performance of a walk-in cooler working with R22 and its substitute R422D are experimentally studied. The experimental investigation was carried out considering three different operating conditions; in particular, the AHRI standard has been used as reference for operating conditions. All tests were run at steady state conditions and keeping the external air temperature at 35 C. The experimental analysis allowed the determination of cooling capacity, the electrical power absorbed, the COP and other variables characterizing the working of the plant. The results demonstrated that the cooling capacity for R422D was lower than for R22, while the electrical power absorbed with R422D was higher than that with R22. As consequence, the COP of R422D was lower than that of R22. Furthermore, technical proposals are introduced with the aim of improving the overall performances of those plants, which could be retrofitted with R422D