Vehicle hvac system

A vehicle heating, ventilation, and air conditioning (HVAC) system comprising:

• 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, wherein the water-cooled heat exchanger and the exterior heat exchanger are connected in parallel to a refrigerant circulation path;
• 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.