A comparative performance study of a direct expansion geothermal evaporator using R410A and R407C as refrigerant alternatives to R22

Abstract

This study presents a comparative performance analysis of a direct expansion geothermal evaporator using R410A, R407C and R22 as refrigerants. The main goal is to predict the best refrigerant capable of serving as a substitute for R22. A validated geothermal evaporator model developed by our research team was used. The simulation results show that for low refrigerant flow rate, the R410A DX evaporator shows better performance than that of R22, but from the pressure drop observed and superheating recorded with the former, it can be concluded that R407C is the best fluid to replace R22 in the DX GHP. That notwithstanding, to minimize pressure drop, especially for high refrigerant flow rates, R410A would be a better choice for the design of new DX systems.