A combination water heating, air conditioning refrigerant system is described. The combined system includes a plurality of independently adjustable electronic expansion valves. The expansion valves can independently modulate the delivery of high-temperature, high-pressure refrigerant to either a water heat exchanger or an outside condenser. A controller can receive input signals, including temperature signals from one or more temperature sensors that indicate the temperature at various locations of the system. The temperature signals include one or more of water temperature signals, ambient air temperature signals, or refrigerant super heat temperatures signals. In response to the input signals, the controller can output control signals to one or more of the plurality of electronic expansion valves.

A method for remotely diagnosing an abnormality in a climate control device includes the following steps: (a) receiving, at a diagnostic device remote from the climate control device, a signal representing one or more operating parameters of the climate control device, (b) generating, at the diagnostic device, an operating state metric at least partially from the signal representing the one or more operating parameters, (c) comparing, at the remote diagnostic device, the operating state metric to a reference metric, and (d) diagnosing, at the remote diagnostic device, the abnormality in response to a difference between the operating state metric and the reference metric.

A combination water heating, air conditioning refrigerant system is described. The combined system includes a plurality of independently adjustable electronic expansion valves. The expansion valves can independently modulate the delivery of high-temperature, high-pressure refrigerant to either a water heat exchanger or an outside condenser. A controller can receive input signals, including temperature signals from one or more temperature sensors that indicate the temperature at various locations of the system. The temperature signals include one or more of water temperature signals, ambient air temperature signals, or refrigerant super heat temperatures signals. In response to the input signals, the controller can output control signals to one or more of the plurality of electronic expansion valves.

A supply-water warming system includes a steam compression heat pump circuit, a heat recovery heat exchanger, a heat source fluid line in which heat source fluid flows in the heat recovery heat exchanger and the evaporator in this order, a water supply line in which supply water flows in the heat recovery heat exchanger and the condenser in this order, a refrigerant flow rate adjustment section controlled based on the superheat degree of gas refrigerant flowing into the compressor and configured to adjust a refrigerant flow rate, a supply water flow rate adjustment section controlled based on the tapping temperature of the supply water flowing out of the condenser and configured to adjust a supply water flow rate, and a control section configured to control the refrigerant flow rate adjustment section and the supply water flow rate adjustment section.

A heating system includes a refrigerant boiler including a heat source for heating a refrigerant from a liquid state to a vapor state, a boiler outlet and a boiler inlet; a heat exchanger in fluid communication with the refrigerant boiler, the heat exchanger including a upper manifold having a heat exchanger inlet coupled to the boiler outlet, a lower manifold having a heat exchanger outlet coupled to the boiler inlet and a plurality of tubes connecting the upper manifold and the lower manifold, wherein refrigerant passes from the upper manifold to the lower manifold via gravity; and a fan moving air over the heat exchanger to define supply air for a space to be heated.

An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

An apparatus for heating water has a tank for storing water and an air conditioning system that defines a refrigerant flow path through which refrigerant flows. The refrigerant flow path passes through the heat exchanger so that refrigerant heat is contributed to the tank. A control system controls operation of the water heating apparatus.

A method for controlling an operating discharge pressure in a multi-purpose HVAC system including an outdoor unit, and an indoor unit, the HVAC system including a plurality of flow control valves configured to isolate the indoor unit from the multi-purpose HVAC system, a compressor and a controller, operably coupled to a water heater module, the water heater module including at least one valve, the controller executing a method including operating the multi-purpose HVAC system in a water heating mode, monitoring the operating discharge pressure from the compressor; and generating a signal commanding at least one of the plurality of control valves to isolate the indoor unit from the outdoor unit and water heating module and direct high pressure refrigerant to the indoor unit when the operating discharge pressure is greater than or equal to a predetermined pressure value.

A heat-pump water heater includes a refrigerant circuit, a water circuit, and a controller. The refrigerant circuit includes a main circuit and a bypass circuit. The main circuit includes a compressor, a water heat exchanger, a first pressure-reducing device, an air heat exchanger, and an air-sending device. The bypass circuit includes a second pressure-reducing device. The water circuit includes a hot water tank, a water pump, and the water heater exchanger. In a night-time hot-water supply mode, the controller causes the water pump with a lowest frequency set in advance, causes the compressor with a lowest frequency set in advance, and stops the air-sending device.

A method for controlling an operating discharge pressure in a multi-purpose HVAC system including an outdoor unit, and an indoor unit, the HVAC system including a plurality of flow control valves configured to isolate a the indoor unit from the multi-purpose HVAC system, a compressor and a controller, operably coupled to a water heater module, the water heater module including at least one valve, the controller executing a method including operating the multi-purpose HVAC system in a water heating mode, monitoring the operating discharge pressure from the compressor; and generating a signal commanding at least one of the plurality of control valves to isolate the indoor unit from the outdoor unit and water heating module and direct high pressure refrigerant to the indoor unit when the operating discharge pressure is greater than or equal to a predetermined pressure value.