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 air-conditioning hot-water supply device includes a first refrigerant passage connecting a compressor and a decompressor, a second refrigerant passage branching from between the compressor and a first solenoid valve and connecting a second solenoid valve, a hot-water supply heat exchanger, and the decompressor, a pressure sensor configured to measure discharge pressure of the compressor, and a control device configured to adjust an operational frequency of the compressor and adjust an opening degree of a valve of the decompressor. The control device is configured to calculate a condensing temperature from the discharge pressure, and perform operation in one of an air conditioning prioritized mode in which a preset operational frequency of the compressor is changed, and an energy saving prioritized mode in which the opening degree of the valve of the decompressor is changed, when the condensing temperature is not lower than a set condensing temperature.

A heat pump water heater has a tank, a heat source, and a heat pump system. The heat pump system has a refrigerant path, at least a portion of which is in thermal communication with the water tank volume so that heat transfers from refrigerant to the water tank volume. A fan causes air to flow through a housing, and another portion of the refrigerant path includes an evaporator in the housing. The fan is within the housing and may further be within a second housing. The first housing may comprise a baffle to direct air flow. The fan may be a variable speed fan in communication with a controller, so that the controller controls the fan speed depending on a temperature of the refrigerant.

An outdoor unit includes an air heat exchanger; a compressor; a water heat exchanger; an expansion valve; a fan that moves air outside the outdoor unit into the air heat exchanger; a motor that rotates the fan; a power device used for driving the compressor; a heat sink located in a space that is an extension portion beyond the air heat exchanger, of a channel of air moved by rotation of the fan during heating of the water from outside the outdoor unit into the air heat exchanger, where the heat sink dissipates heat generated by the power device during driving of the compressor; and a control unit that provides control, upon completion of a water heating operation, to drive the compressor, to open the expansion valve, and to rotate the fan in the same direction as the rotation direction of the fan during heating of the water.

The present invention provides an outdoor unit of a heat pump water heater that has improved heat dissipation performance of an electrical unit achieved by improving the placement of the electrical unit and a remote controller. A compressor 31 is placed on one side in an exterior case 51, while an evaporator 32 and an air blower 34 are placed lateral to the compressor. An electrical unit 70 is placed on one side in the exterior case below a top panel 56, and a remote controller 71 is placed between a side plate 55B of the exterior case and the electrical unit. A heat dissipation section 72 is provided on a portion of the electrical unit, the portion being positioned on the opposite side from the remote controller, and is positioned within a ventilation path of the air blower.

A heat pump boiler is disclosed. The heat pump boiler includes a compressor. The heat pump boiler further includes an exterior heat exchanger that is configured to transfer heat between refrigerant and exterior air. The heat pump boiler further includes an interior heat exchanger that is configured to transfer heat between refrigerant and water. The heat pump boiler further includes a channel change valve that is configured to provide refrigerant compressed by the compressor to the exterior heat exchanger or the interior heat exchanger. The heat pump boiler further includes a first boiler heat exchanger that is configured to heat water that has passed through the interior heat exchanger from heat generated through combustion. The heat pump boiler further includes a second boiler heat exchanger that is configured to transfer heat between refrigerant and gas discharged from the first boiler heat exchanger.

An operating method of a heat-storage system includes the steps of executing a first operating mode to supply heat to a first hydrogen storage alloy in a first tank, to cause movement of hydrogen from the first hydrogen storage alloy in the first tank to a second hydrogen storage alloy in a second tank, the second hydrogen storage alloy being different from the first hydrogen storage alloy in dissociation pressure characteristic with respect to an alloy temperature, and executing a second operating mode to supply cold of outside air to the first hydrogen storage alloy, to cause movement of hydrogen from the second hydrogen storage alloy in the second tank to the first hydrogen storage alloy in the first tank, in which the step of executing the first operating mode includes a step of storing a temperature generated in the second hydrogen storage alloy in a heat storage device.

A method of heating water in a water storage tank. The method includes: selecting an outlet port and an inlet port from at least three ports located in the tank at different heights along a vertical direction. The outlet port is below the inlet port. The method further includes extracting water from the outlet port, supplying the extracted water to an external heat exchanger configured for heating the extracted water, and delivering heated water from the heat exchanger to the selected inlet port.

The present invention relates to a method for controlling a pump for feeding fluid (F) into a heating system (1000). The heating system has a hot fluid tank (HFT) receiving fluid from an associated fluid reservoir line (5) with an incoming fluid mass flow rate (dm.sub.cw/dt). A pump (P) receives fluid from the line, and pumps the received fluid with a mass flow rate (dm.sub.c/dt). A heat exchanging unit (HX) transfers heat (Q) to the fluid (F) from a medium (R). The transferred heat (Q) is maximized by controlling the pump (P1) in response to this information indicative of the transferred heat (Q), the fluid mass flow rate delivered by the pump thereby having a minimum as a function of the incoming fluid mass flow rate (dm.sub.cw/dt) when maximizing the transferred heat. The invention provides significantly improved heat transfer to the fluid and power savings for the pump. The invention also relates to a heating system, e.g. a heat pump system.

Non-potable, utility water is circulated by a pump in a closed loop. The utility water is heated by a heat pump. Heat exchange from the utility water heats domestic hot water on demand, eliminating or reducing the need for domestic hot water storage tanks and storage of large quantities of water. In the present invention, fluctuations in condenser water temperature are dampened internally in a condenser water buffer and a control system.