Thermodynamic performance of air conditioners working with R417A and R424A as alternatives to R22.
Abstract The energy and exergy parameters of R417A and R424A gases which can be used instead of R22 were experimentally investigated for a split-type air conditioner. Although GWP amounts of the available alternative refrigerants are higher compared to R22, their ODP values are zero. The experiments were accomplished for three different ambient temperature values of 25 °C, 30 °C and 35 °C. The covered test conditions were carried out for steady-state case while keeping the inside medium temperature at constant temperature of 22 °C. The cooling capacity, COP, exergy destruction of components in the unit (i.e., compressor, condenser, evaporator, and expansion device), exergetic efficiency and some other parameters of the system were determined. COP values for the refrigerants of R417A and R424A were noted to be smaller compared to R22. Similarly, both isentropic efficiency of the compressor and exergetic efficiency of the system were higher for R22. The use of R424A will be more suitable rather than R417A since COP values of R417A are lower about 5–16% compared to R424A. The COP value of R22 is greater than that of R417A and R424A by amounts of 17–23% and 4–18%, respectively. At the greater evaporation temperatures (0 °C to +5 °C as in the air-conditioners) it can be stated that R424A is more preferable than R417A as an alternative refrigerant to R22.