A hot water supply apparatus includes a heat pump device in which a compressor and a heat exchanger are connected, a heat medium circuit connected to the heat pump device via the heat exchanger, a tank that stores water after the water exchanges heat with a heat medium of the heat medium circuit, two tank-temperature detection units attached at different heights to the tank and each detects a temperature of water in the tank, and a controller that controls, by using a value detected by each of the two tank-temperature detection units, a temperature of water in the tank. The controller sets a target hot water supply temperature based on a stored-hot-water temperature detected by one of the two tank temperature detection units and a within-tank temperature difference that is a difference between temperatures within the tank detected by the two tank-temperature detection units.

A water heater appliance, including methods of operation, is provided herein. The water heater appliance may include a casing, a tank, an inlet conduit, an electric heating system, and a controller coupled to an auxiliary power generator. The tank may be disposed within the casing and define an inlet and an outlet. The inlet conduit may be mounted to the tank at the inlet of the tank. The controller may be operably coupled to the electric heating system and configured to initiate a heating cycle. The heating cycle may include identifying a daily peak auxiliary power period, determining a contemporary voltage reading at the water heater appliance, predicting an occurrence of the daily peak auxiliary power period from the auxiliary power generator, and heating water within the water heater at the predicted occurrence of the daily peak auxiliary power period.

A controller converts a detection result of an infrared sensor into overall thermal image data representing a temperature distribution within an infrared detection range of the infrared sensor, calculates, based on the overall thermal image data, a floor area of an air-conditioned space, and obtains, based on the overall thermal image data, floor thermal image data including a plurality of element data items each including coordinates within the floor area and a floor temperature within the floor area associated with the coordinates. The controller determines the presence or absence of a floor heating device in the air-conditioned space. When the controller determines the presence of the floor heating device, the controller determines, based on data that is included in the floor thermal image data and corresponds to an installation region of the floor heating device, an operation state of the floor heating device.

A hot water supply system that can reduce energy consumption is provided. The hot water supply system includes a liquid heater for heating a liquid, a liquid-water heat exchanger, a water-heating circuit in which the liquid is circulated between the liquid heater and the liquid-water heat exchanger, a lower outward path for leading water from a lower part of a hot water storage tank to the liquid-water heat exchanger, the upper return path for leading the water from the liquid-water heat exchanger to an upper part of the hot water storage tank, a middle outward path for leading the water from a middle part of the hot water storage tank to the liquid-water heat exchanger, a middle return path for leading the water from the liquid-water heat exchanger to a middle part of the hot water storage tank.

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.

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.

An electric water heater appliance is provided herein. The electric water heater appliance may include a tank, an electric heating element, and a temperature sensor. The tank may define an interior volume extending from a top portion to a bottom portion. The interior volume may define a volume height along a vertical direction between the bottom portion and the top portion. The electric heating element may be operable to heat water within the interior volume. The temperature sensor may be attached to the tank above the electric heating element. A sensor gap may be defined along the vertical direction between the electric heating element and the temperature sensor.

Heat pump system (100) comprising a heat medium circuit (210,220,230,240,250,310,320,410,420,430,440,450,460) in turn comprising at least three heat exchanging means (314,315,315,422,433,452) between the heat medium and a respective heat source or sink selected from outdoor air, a water body, the ground, indoor air, pool water or tap water, a valve means (311,312,313,421,431,451) arranged to selectively direct the heat medium to at least two of said heat exchanging means, and a control means (500). The invention is characterized in that the heat pump system comprises temperature sensors (314a,314b;315a,315b;316a,316b;423,424,425;432,434,435) both upstream and downstream of at least one of said heat exchanging means, in that the system determines, based upon temperature measurement values comprising at least one value read from said sensors, to what heat exchanging means the heat medium is to be directed, and in that when heat medium is not directed to a certain heat exchanging means a measured temperature value is read upstream and downstream of the certain heat exchanging means, and in that an alert is set off in case the values differ by more than a predetermined value. The invention also relates to a method.

A heat pump apparatus includes a use-side heat exchanger that cause heat exchange to be performed between a heat medium flowing from a heat-storage heat exchanger and a heat usage medium, and a flow-passage switching device that switches a flow passage for the heat medium to a first flow passage that circulates through a heat-reception-side heat exchanger and the heat-storage heat exchanger without extends through the use-side heat exchanger or a second flow passage that circulates through the heat-reception-side heat exchanger and the heat-storage heat exchanger via the use-side heat exchanger. Even when the temperature of the heat storage medium rises, heat received from a heat source can be stored in the heat storage medium by a heat pump, while a decrease of the efficiency of the heat pump can be reduced.

A heat pump apparatus includes: a refrigerant circuit which circulates refrigerant; a heat medium circuit which makes a heat medium flow; a heat exchanger which cause heat exchange to be performed between the refrigerant and the heat medium; and an indoor unit which houses at least the heat exchanger. The heat exchanger has a double-wall structure. The indoor unit includes a container which houses the heat exchanger. In the container, a first opening port is formed to communicate with an outdoor space without communicating with an indoor space.