HO-82-01-2 -- The Effect of Location on the Predicted Performance of a Heat Pump Water Heater PDF

Laboratory testing and field testing have shown that a heat pump water heater (HPWH) uses about half the electrical energy input that an electric resistance water beater does. However, since the HPWH extracts energy from the air in its environment, the question arises as to how this energy extraction would affect the house heating, ventilating, and air-conditioning (HVAQ system if the HPWH were located in a conditioned space of a household . A second question concerns the savings obtained by locating the HPWH in an unconditioned space such as a garage or basement.

A computer study of these effects was carried out at the Oak Ridge National Laboratory. Since geography, house construction, type and efficiency of HVAC system, and hot water usage will all affect the effective performance, some of these parameters were fixed and some were allowed to vary in the study.