An air conditioning system for a vehicle and a method of operation is disclosed. The air conditioning system includes a primary refrigerant loop and a secondary liquid loop. The primary refrigerant loop includes a compressor configured to be selectively driven by the engine, a condenser, an expansion device and a refrigerant-to-liquid heat exchanger. The secondary liquid loop includes the refrigerant-to-liquid heat exchanger, a thermal storage reservoir within which the refrigerant-to-liquid heat exchanger is mounted, a pump configured to pump a liquid through the refrigerant-to-liquid heat exchanger, a liquid-to-air heat exchanger configured to mount in a HVAC module and receive the liquid from the refrigerant-to-liquid heat exchanger, and a liquid flow valve configured to selectively direct the liquid directly to the pump or through the thermal storage reservoir to the pump.