Systems and methods for integrating a water heating unit and a heat pump

An integrated heat pump-water heater system, comprising:

• a heat pump for circulating refrigerant in a refrigerant loop, the heat pump operable in multiple operating modes for an indoor space, the heat pump comprising:
• a compressor positioned on the refrigerant loop,
• an indoor air-refrigerant heat exchanger (ARHX) positioned on the refrigerant loop,
• an outdoor ARHX positioned on the refrigerant loop, and
• a reversing valve positioned on the refrigerant loop and connected to the compressor and positionable to direct flow of the refrigerant between the indoor ARHX and the outdoor ARHX based on the operating mode of the heat pump;
• a water heater comprising a water loop and a water-refrigerant heat exchanger (WRHX) that thermally connects water in the water loop and the refrigerant in the refrigerant loop;
• and
• a network of valves positioned on the refrigerant loop and connected to the reversing valve, the indoor ARHX, and the outdoor ARHX, wherein the network of valves is positionable to direct the flow of the refrigerant through the WRHX such that the refrigerant is able to heat the water via the WRHX in each operating mode of the heat pump,
• wherein, in a space heating mode, the reversing valve is positioned to direct the flow of the refrigerant from the compressor towards the network of valves, and to direct the flow of the refrigerant from the outdoor ARHX towards the compressor, and the network of valves is positionable to direct the flow of the refrigerant from the reversing valve, towards and successively through the WRHX, the indoor ARHX, and the outdoor ARHX,
• wherein, in a space cooling mode, the reversing valve is positioned to direct the flow of the refrigerant from the compressor towards the outdoor ARHX, and to direct the flow of the refrigerant from the network of valves towards the compressor, and the network of valves is positionable to direct the flow of the refrigerant from the outdoor ARHX, towards and successively through the WRHX and the indoor ARHX.