Abstract: An extended engine off passenger climate control system utilizes an advanced temperature control module in combination with modifications to the conventional heating/ventilation/air conditioning (HVAC) system to provide occupants in the passenger cabin of a hybrid electric motor vehicle with adequate heat or air conditioning for up to two minutes after the gasoline engine is turned off. A two stage orifice between the condenser and the evaporator of the air conditioning system slows the equilibration of the pressures on the high pressure side and low pressure side of the air conditioning system when the air conditioner compressor is turned off, allowing the passenger cabin to continue receiving cooling air even when the gasoline engine, and thus the compressor, is off. An auxiliary engine coolant pump circulates heated engine coolant through the heater core when the gasoline engine is turned off, thus providing heat when conditions require passenger cabin heating.

Abstract: An extended engine off passenger climate control system utilizes an advanced temperature control module in combination with modifications to the conventional heating/ventilation/air conditioning (HVAC) system to provide occupants in the passenger cabin of a hybrid electric motor vehicle with adequate heat or air conditioning for up to two minutes after the gasoline engine is turned off. A two stage orifice between the condenser and the evaporator of the air conditioning system slows the equilibration of the pressures on the high pressure side and low pressure side of the air conditioning system when the air conditioner compressor is turned off, allowing the passenger cabin to continue receiving cooling air even when the gasoline engine, and thus the compressor, is off. An auxiliary engine coolant pump circulates heated engine coolant through the heater core when the gasoline engine is turned off, thus providing heat when conditions require passenger cabin heating.