Heat pump hvac system for vehicle with deice functionality

A method of operating a closed loop heat pump system:

• wherein the closed loop heat pump system comprises a closed loop for refrigerant flow, the closed loop comprises a plurality of components that refrigerant flows through, the plurality of components include an evaporator, an expansion valve, a compressor, a heat pump heater that comprises a first condenser, and a second condenser wherein refrigerant flows through loop and through the components continuously,
• wherein the expansion valve is a first expansion valve that is disposed upstream of and adjacent to the evaporator, wherein the first expansion valve is remotely controllable by a controller in order to adjust a refrigerant pressure drop that occurs as refrigerant passes through the first expansion valve,
• the method comprises the controller operating the heat pump system in a first mode wherein the heat pump heater transfers heat into a vehicle passenger compartment via a forced air flow thereby, and the evaporator to remove heat from the forced air that flows thereby, wherein during a first mode of operation of the system a refrigerant entering the evaporator may be at or less than a temperature of air that surrounds the evaporator causing heat transfer from air outside of the evaporator through one or more outer walls of the evaporator to the refrigerant flowing therethrough, thereby causing moisture upon the outer heat transfer surface to freeze over time with continued operation;
• further comprising the controller operating the heat pump system periodically in a second mode of operation by adjusting a condition of the first expansion valve to cause the pressure drop of the refrigerant as the refrigerant flows through the first expansion valve to decrease such that a pressure of refrigerant entering the evaporator increases such that a corresponding refrigerant temperature increases thereby transferring heat through one or more walls of the evaporator to the outer heat transfer surface to cause the frozen layer upon the outer surface of the evaporator to melt.