The applications of hot water in the industrial, domestic and mining applications are numerous, and these are only a few of the core areas of use. In these applications fossil fuels and electrical resistance systems are usually used to heat water to temperatures near boiling point. The refrigerant R22, that is currently being used in hot water heat pumps, delivers hot water temperatures from 60 °C to 65 °C. This limits the applications of hot water heat pumps.
This analytical study uses three comparison methods to investigate and compare the potential of a non-azeotropic refrigerant mixture consisting of R22 and R142b. From the results different advantages of non-azeotropic refrigerant mixtures are evident. Depending on the application, if the results of a non-azeotropic refrigerant mixture are compared with a pure R22 heat pump, an increase in hot water temperatures to above boiling point, an increase in coefficient of performance, an increase in capacity and a decrease in compressor pressure ratio are possible. Unfortunately, not all these advantages are valid for each application. For instance, extremely high hot water temperatures are obtained, whilst the heating capacity is excessively low.