Experiment was carried out on the R417a and R22 used in air-source heat pump water heater under 2 different working conditions of 20 ℃ and 7 ℃.The discharge pressure,power in-put and coefficient of performance (COP)of the R417a were analyzed in comparison with R22. Results show that under the two working conditions,the discharge pressure,power input and power output of R417a system are lower than those of R22,and its heating output is reliable as a result of the effect by the temperature of hot water.Though the COP of R417a reduces rapidly, its average COP is higher than that of R22.
pyrologyR417aheat pump water heateralternative of refrigerants