The purpose of this paper is not to recommend specific changes in heat pump designs. Rather, its purpose is to draw attention to those changing economic conditions which suggest that higher system first costs may be affordable as the cost of energy for operating such systems moves upward. The aim is to show only the differences in energy costs. due to specified alterations in equipment design.

It is intended to show this relationship by the example of a single house design, located in different climatic areas, and with identified modifications to equipment performance.