Abstract: A compressor assembly including a housing that encloses a sealed interior volume and defines an inlet opening and an outlet opening. Refrigerant is communicated from a suction line into the interior volume through the inlet opening. Refrigerant is communicated from the interior volume to a discharge line through the outlet opening. A first compressor mechanism is disposed within the interior volume and is adapted to compress the refrigerant. A first fitting is mounted on an exterior surface of the housing and is in communication with one of the inlet and outlet openings. The first fitting defines a first passageway for communicating the refrigerant between the one opening and a respective one of the suction and discharge refrigerant lines. The fitting further defines a first duct in communication with the first passageway. A first pressure relief valve is mounted in communication with the first duct.

Abstract: A compressor assembly including a motor having a stator and a rotor, and a drive shaft having an elongate central portion and first and second end portions located on opposite ends of the central portion. The shaft defines a rotational axis and extends through the rotor with the central portion rotationally secured to the rotor and the first and second end portions disposed proximate opposite ends of the motor. First and second compressor mechanisms are disposed proximate opposite ends of the motor and are operatively coupled to the first and second end portions, respectively, of the shaft. First end portion, second end portion and central portion define respective first, second and third cross-sectional configurations oriented perpendicular to the rotational axis. Each of first and second cross-sectional configurations has an outer perimeter disposed radially within the outer perimeter of the third cross-sectional configuration relative to the rotational axis.

Abstract: A water heating system including a water storage vessel; a water circuit; first and second heat exchangers operably disposed in the water circuit; and a vapor compression system defining a refrigerant circuit. The vapor compression system includes first and second compressor mechanisms. The first compressor mechanism compresses the refrigerant from suction pressure to intermediate pressure. The second compressor mechanism compresses the refrigerant from the intermediate pressure to a supercritical discharge pressure. The first heat exchanger is operably disposed in the refrigerant circuit between the first and second compressor mechanisms, and exchanges heat between intermediate pressure refrigerant and water. An expansion device is operably disposed in the refrigerant circuit. An evaporator is operably disposed in the refrigerant circuit between expansion device and first compressor mechanism.