Abstract: For use with a heat pump to increase cooling and heating efficiency, between an outdoor condenser and an indoor evaporator, a refrigerant receiver or sub-cooler is provided within the high pressure liquid refrigerant portion of the system, including at least one high flow, low pressure release check valve having an internal control element with a refrigerant turbulence producing backside that serves as an incremental expansion device to cool, by incremental expansion, and heat, by turbulence, the high pressure liquid refrigerant.

Abstract: For use with a refrigeration system to increase cooling efficiency, between an outdoor condenser and an indoor evaporator, a refrigerant receiver-sub-cooler is provided including, immediately before the receiver-sub-cooler, but still within the high pressure liquid refrigerant portion of the system, a high flow, low pressure release check valve, having a generally flat backside refrigerant flow control element, that serves as an incremental expansion device to cool partially the high pressure liquid refrigerant before the refrigerant enters the traditional expansion device immediately prior to the indoor evaporator.

Abstract: For use with a heat pump to increase cold weather heating efficiency, a supplemental heat exchanger and associated refrigerant flow lines for generating additional expanded refrigerant and transferring the additional expanded refrigerant to the heat pump compressor during the cold outside conditions, included isn a monitoring system for detecting and actively regulating the refrigerant pressure and temperature at a location in the supplemental heat exchanger and associated refrigerant flow lines just prior to the refrigerant entering the compressor. The monitoring system automatically connects the supplemental heat pump, to enhance the heating cycle capabilities, and disconnects the supplemental heat pump, when the enhanced heating cycle capabilities are no longer required.