The effect of control devices that could be installed by homeowners on heat pumps was investigated with regard to total energy used, hourly maximum electrical demand, and spread of the demand over a monthly time period. Groups of houses representative of electric substation scale loading had microprocessor-based thermostats and outdoor heat pump thermostats installed. The major results obtained were: (1) the microprocessor-based setback thermostats significantly reduced the total energy used(20°4%) and the maximum demand, and(2)the outdoor heat pump thermostats significantly reduced the total energy used (7.9%)the maximum demand.

Units: Dual