专用热泵热水器（HPWPs）正在上市。产品文献和现场研究表明，HPWHs的COP主要受环境空气温度的影响，仅受供水温度的轻微影响。根据实验结果，热水排放量和储罐容量也会影响HPWHs的运行效率。这两个因素会影响进入HPWH的水温。建议预测HPWH运行性能的标准试验不应仅限于冷启动恢复试验。引文:ASHRAE Transactions，1984年，第90卷，pt。佐治亚州亚特兰大1A

Dedicated heat pump water heaters (HPWPs) are being marketed. Product literature and field studies imply that the COP of the HPWHs is mainly affected by ambient air temperatures and only slightly affected by the temperature of the water supply. Based on the experimental results presented, the operational efficiency of HPWHs is also affected by quantity of hot water drawoff and capacity of storage tank. These two factors influence water temperature entering the HPWH. The suggestion is made that standard tests for predicting HPWH operational performance should not be confined to just cold-start recovery tests.