Heat pump and air conditioning system for a vehicle

A heating and cooling system for a vehicle having an engine and a passenger compartment, the heating and cooling system comprising:

• a first coolant loop having a coolant outlet line and a coolant inlet line adapted to couple to the engine, a heater core, a first coolant/refrigerant heat exchanger, and a first coolant valve and a second coolant valve for selectively directing flow of a coolant from the coolant outlet line to the coolant inlet line through one of the heater core and the first coolant/refrigerant heat exchanger;
• a second coolant loop having a second coolant/refrigerant heat exchanger with a coolant inlet line and a coolant outlet line which are selectively connected for coolant flow through the heater core by the first coolant valve and the second coolant valve;
• a pump operatively engaging at least one of the first coolant loop and the second coolant loop;
• and
• a refrigerant loop having a compressor with an inlet and an outlet, a first refrigerant valve for selectively directing the flow of a refrigerant from the compressor outlet to one of a condenser and the second coolant/refrigerant heat exchanger, a first refrigerant passage connected to the condenser for directing the flow of the refrigerant from the condenser, through a first expansion device and to an evaporator, and a second refrigerant line connected to the second coolant/refrigerant heat exchanger for directing the flow of the refrigerant from the second coolant/refrigerant heat exchanger, through a second expansion device and to the first coolant/refrigerant heat exchanger.

A method of providing heating and cooling to a passenger compartment of a vehicle having an engine, the method comprising the steps of:

• selectively circulating a coolant from the engine, through at least one of a heater core and a first coolant/refrigerant heat exchanger, and back to the engine;
• selectively circulating the coolant from a pump, through one of a second coolant/refrigerant heat exchanger and the heater core, through the other of the second coolant/refrigerant heat exchanger and the heater core, and back to the pump;
• and
• selectively circulating a refrigerant from a compressor and back to the compressor through one of a first refrigerant path, having a condenser and an evaporator, and a first expansion device between the condenser and the evaporator, and a second refrigerant path, having the second coolant/refrigerant heat exchanger, the first coolant/refrigerant heat exchanger, and a second expansion device between the second coolant/refrigerant heat exchanger and the first coolant/refrigerant heat exchanger.