Patent ID: 8869545
Filing Date: 2014-10-28
Classification: F25B,F25D,F28D,F28F

Abstract:
1. A heat pump having an improved defrost cycle, the heat pump comprising: a compressor; at least one expansion device; a first heat exchanger comprising: a first refrigerant conduit connecting a discharge port on the compressor to the at least one first connection point of the first heat exchanger; a second refrigerant conduit connecting the second connection point of the first heat exchanger to the at least one expansion device; a third refrigerant conduit connecting the first refrigerant conduit to the third connection point of the first heat exchanger; a defrost valve located in the third refrigerant conduit between the first refrigerant conduit and the third connection point of the first heat exchanger, wherein, when the defrost valve is closed, refrigerant flow through the third refrigerant conduit is blocked; and a control system that controls the defrost valve and opens the defrost valve during the defrost cycle allowing refrigerant to flow through the third refrigerant conduit to the third connection point to the first heat exchanger; wherein: