Heat pump operating system - defrost on evaporation pressure falling to specified value and continues operation after set period

摘要

The heat pump operating system periodically stops the heating action and defrosts the evaporator. Defrosting takes place when the evaporation pressure in the latter has fallen to a first specified value, and the heating operation is continued if stoppage has occurred at least twice within a preset time, in order to reach this value. After a lower value of the evaporation pressure has been reached, the evaporator is defrosted again. For the first value of a pressure, corresponding to an evaporation temp. of between -3 and -14 deg.C can be selected. The preset defrosting period may be 30 min.