VEHICLE HVAC SYSTEM

An embodiment HVAC system includes a compressor, an interior condenser disposed on a downstream side of the compressor, a refrigerant heat exchanger located between the interior condenser and the compressor, wherein the refrigerant heat exchanger is configured to transfer heat between an expanded refrigerant and a non-expanded refrigerant of a refrigerant discharged from the interior condenser, a water-cooled heat exchanger disposed on a downstream side of the interior condenser and configured to transfer heat between the refrigerant and a coolant circulating in a coolant system, an exterior heat exchanger disposed on the downstream side of the interior condenser and configured to transfer heat between the refrigerant and ambient air, and a control valve unit configured to control a flow of the refrigerant and expansion and/or non-expansion of the refrigerant between the interior condenser, the water-cooled heat exchanger, the exterior heat exchanger, and the refrigerant heat exchanger.