Laboratory tests of a residential unitary water-source heat pump

The performance of a residential heat pump was measured in the laboratory over a broad range of source water temperatures (40 F to 90 F). Tests were performed in both heating and cooling operational modes and for both steady state and cyclic operation. For both heating and cooling operations, the unit capacity and coefficient of performance were found to be linear functions of the average of the unit source and outlet water temperatures. In heating, the unit capacity, COP, and part load performance increased with increasing water temperature. In cooling, the unit capacity, COP, and part load performance decreased with increasing water temperature. The measured degradation coefficients ranged from 0.09 to 0.21 for heating and from 0.10 to 0.18 for cooling.