风冷热泵热水器有一个恰当容积的保温水箱，利用热泵将保温水箱内部的水加热，由于在加热过程中热水与冷水之间相对运动，使热水区逐渐集中在保温水箱的顶部，冷水集中在水箱的底部，随着热泵的不断加热，最终整个保温水箱的水温达到一个均衡的值。
The air-cooled heat pump water heater has a proper volume of heat preservation water tank. The heat pump is used to heat the water inside the heat preservation water tank. Due to the relative movement between the hot water and the cold water in the heating process, the hot water area is gradually concentrated on the top of the heat preservation water tank, and the cold water is concentrated on the bottom of the water tank. With the continuous heating of the heat pump, the water temperature of the whole heat preservation water tank finally reaches a balanced value.