两台热泵在几个“开”-“关”循环下进行测试，以确定部分负载条件下的性能。此外，在结霜条件下，对热泵进行了全容量测试，包括时间温度和按需除霜控制。目的是开发用于季节性绩效模型的模拟。对于“开”-“关”循环和除霜循环，发现COP作为稳态COP的一部分可以通过幂律关系进行预测，涉及容量作为稳态容量的一部分。结霜分两步进行，最初逐渐结霜到过渡点，然后迅速结霜，直到开始除霜循环。根据室外空气温度和室外空气比湿度与室外盘管温度下饱和空气比湿度之间的差异，预测了结霜条件下的热容。 引用:ASHRAE交易，第87卷，第一部分，伊利诺伊州芝加哥

Two heat pumps were tested at several "on"-"off" cycles to determine performance at part load conditions. Also, the heat pumps were tested at full capacity under frost buildup conditions with both time-temperature and demand defrost controls. The objectives were to develop simulations for use in seasonal performance models. For "on"-"off" cycling and defrost cycles, it was found that COP as a fraction of steady state COP could be predicted with power law relationships involving capacity as a fraction of steady state capacity. Frost buildup occurred in a two-step process, with initial gradual frost buildup to a transition point followed by rapid frost buildup until a defrost cycle was initiated. Heat capacities under frost buildup conditions were predicted as a function of outdoor air temperature and difference between specific humidity of the outdoor air and specific humidity of saturated air at outdoor coil temperatures.