Mild ambient vehicular heat pump system

A vehicular heat pump system for controlling the temperature of a passenger compartment and vehicle battery is provided. The heat pump system may include a cooling mode and a heating mode. The components of each of the respective heating and cooling circuits may include: a compressor, an AC condenser, a heat pump condenser, a cabin evaporator, a heat pump evaporator, a receiver/dryer, a plurality of expansion devices, and a plurality of flow control valves. The use of multiple evaporators and condensers eliminates the need to reverse the direction of refrigerant flow upon a change in operating mode; therefore, the position of the low-pressure side of the system remains constant in all operating modes. The low-pressure side of the system is not cooled with ambient air, minimizing the complexity of the system and eliminating the need to interrupt heating mode in order to de-ice the outside heat exchanger.