Heat pump with independent subcooler circuit

A heat pump system having both a heating and a cooling mode comprising:

• A primary condenser, a primary evaporator, a primary expansion device, and a primary compressor coupled together to form a primary closed refrigeration circuit containing a primary refrigerant where the primary condenser is positioned inside an enclosed space and the primary evaporator is positioned outside the enclosed space;
• A secondary condenser, a secondary evaporator, a secondary expansion device, and a secondary compressor, coupled together to form a secondary closed refrigeration circuit containing a secondary refrigerant;
• Wherein the secondary evaporator has a primary refrigerant path through the secondary evaporator that is coupled to the primary closed refrigerant circuit, and a separate secondary refrigerant path through the secondary evaporator coupled to the secondary closed refrigeration circuit, and;
• Wherein the secondary closed refrigeration circuit is positioned upstream from the primary condenser.