Heat exchange apparatus and method having two refrigeration circuits

摘要

Apparatus and method for defrosting a dual refrigeration circuit refrigeration system. During defrost one of the refrigeration circuits is operated to supply heat energy to the frosted heat exchanger of the other circuit and the fan circulating heat transfer media through a heat exchanger of each circuit is reversed such that heat transfer fluid is heated by one refrigeration circuit and then used to defrost a heat exchanger of the other circuit.