ABSTRACT

To meet the need of quality of hot water supply and to reduce the power consumption for generating a hot water, there is a requirement of a new system which is highly efficient, energy-saving, and eco-friendly. Again, refrigerant plays an important role in thermal cycle of heat pump. Hence, it is necessary to choose appropriate type of refrigerant with respect to application. It depends on various factors such as working condition, mass flow rate, temperature, and operating pressure of the refrigerant. Moreover, the properties of that particular refrigerant must be coinciding with the requirement. In this chapter, three refrigerants are considered: R22, R134a, and R410A to evaluate the performance of air water heater system working on standard vapor compression cycle. The performance of the refrigerants R22 and non-ozone-depleting R134a and R410A for high-temperature heat pump application is compared. While most reported works were conducted on residential heat pump with evaporating temperature below 0°C, this study considers higher evaporating temperature from 5 to 24°C. The coefficient of performance (COP) of heat pump at condenser temperatures 60 and 65°C is evaluated and compared for refrigerants R22, R134a, and R410A at different evaporating temperatures with different compressors. It is observed that the heating capacity of R410A is 16% higher than that of R134a and 5% 562lower than that of R22. Moreover, it is observed that the COP of the system decreases with the increase in condenser temperature and increases with the increase in evaporator temperature for all the three refrigerants.