An engineering-economic analysis of residential electric heat pumps

The residential heat pump market is characterized for initial cost and performance. Cost data for forty-one heat pumps are collected. A house is modeled using NASA's Energy-Cost Analysis Program (NECAP) and heating loads are computed for seventeen cities.

Dynamic performance of the heat pumps is estimated by combining the rated performance data with the effects of cycling, frosting, defrosting, and backup heat. Seasonal performance is then estimated by combining the dynamic performance of the heat pumps with the hourly heating requirements produced by NECAP.

Ten different improved systems are analytically studied for cost and performance changes relative to existing heat pumps.

Life cycle cost comparisons are made for the conventional heat pumps and gas, oil, and electric systems, and also the improved heat iS pump systems.

Results show that heat pump costs vary widely for a given capacity. Performance also shows wide variation. . There is a trend indicating better performance costs more. . Seasonal Performance Factors (SPF) vary from a low of 1.14 in Minneapolis to a high of 2.47 in San Diego for the conventional systems. SPFs of the improved systems vary from a low of 1.9l in Minneapolis to 3.86 in San Diego. Annualized Life Cycle Costs (ALCC) indicate that in most cities, gas is the most cost effective way to heat. Heat pumps are the best alternative if gas is unavailable. Some of the improved heat pump systems have lower ALCCs than any of the

conventional systems, which indicates potential for energy savings and cost effectiveness.