Comparison of Field Performance of a High Efficiency Heat Pump with an Without a Desuperheater Water Heater

摘要

An air-to-air heat pump (COP = 3.11 at 47 exp 0 F (8.3 exp 0 C)) run alternately with an electric-resistance water heater and a desuperheater water heater was tested under field conditions at a site near Knoxville, TN. Results from these tests indicate that the desuperheater system has an annual performance factor (measured over a six-month period consisting of three winter and three summer months) 14% better than that of the system using electric resistance water heating. An analytical model predicts a 21% improvement over an entire year with average weather for the desuperheater system. The simple payback period ranges from seven years (for a 21% improvement) to about nine years (for a 14% improvement). (ERA citation 09:012218)