A hot-water supply system heats up water by power generated by power generation means. The hot water supply system includes a compressor and a water heat-up unit. In the hot-water supply system, the compressor compresses refrigerant and circulates the refrigerant through a refrigerant circuit. The water heat-up unit heats up water by changing, in accordance with the generated power, a rotation rate of an electric motor for driving the compressor.

A settings data storage stores unique serial numbers and information regarding a plurality of patterns for alternately switching between normal operation for operating at high capacity and suppressed operation for operating at low capacity each unit time. A pattern specifier determines information for a pattern set in accordance with even and odd serial numbers. A water-heating heat amount determiner determines a heat amount necessary for water heating. A water heating scheduler establishes a water heating plan based on information regarding the pattern determined by the pattern determiner and the water-heating heat amount as determined by the water-heating heat amount determiner. A water heating controller alternately switches between normal operating and suppressed operation to heat water in accordance with the water heating plan established by the water heating scheduler.

A storage type heat pump hot water supplying apparatus includes: control circuitry to control a compressor frequency and a pump rotational speed, the compressor frequency being an operating frequency of the compressor, the pump rotational speed being a rotational speed of a water pump. The control circuitry is configured to control, in a heat accumulating operation for accumulating hot water in the hot water storage tank, the pump rotational speed so that the actual hot water discharge temperature becomes equal to a target hot water discharge temperature. The heat accumulating operation includes a first operation and a second operation after the first operation. The compressor frequency in the first operation is higher than the compressor frequency in the second operation. The target hot water discharge temperature in the first operation is lower than the target hot water discharge temperature in the second operation.

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 method of and system for heating and/or cooling a fluid, the method comprising moving the fluid through a secondary side of a heat exchanger and controlling the temperature of a primary side of the heat exchanger such that the temperature of the primary side of the heat exchanger is maintained substantially at a determined temperature interval from a reference temperature which is a function of at least one of: a temperature of an inlet to the secondary side and a temperature of an outlet of the secondary side.

A method to heat water in an electrical boiler includes storing user's requests of hot water in association with corresponding times of requests, heating water in advance to a next user's request, wherein the next user's request is estimated on the stored user's requests, detecting a start time of a power request from the electrical boiler, detecting a stop time of the power request, determining that a user's request of hot water has occurred if a time difference between the detected stop time and the detected start time is longer than a predetermined time, the predetermined time being a time of activation of the electrical boiler, storing the determined user's request in association with a time of the user's request, estimating a next user's request based on the stored user's request and activating the electrical boiler to heat water in advance with respect to the estimated next user's request.

Provided is a heat pump hot water supply apparatus configured to directly supply water heated by a gas cooler to a utilization side. The heat pump hot water supply apparatus is configured to execute operation modes including a first operation mode and a second operation mode. The first operation mode includes causing the water heated by the gas cooler to return to a water tank as intermediate-temperature water. The second operation mode is an operation mode to be performed after the first operation mode, and includes mixing the water heated by the gas cooler and the intermediate-temperature water in the water tank, and directly supplying the mixed water to the utilization side.

The invention relates to a method for operating a circulation system comprising a cooling device with an input port and an output port for cooling water. The invention also relates to a circulation system for implementing said method.

A water heater appliance includes an electronic mixing valve configured for adjusting a ratio of cold water from a cold water inlet conduit to hot water from a hot water outlet conduit at a mixed water outlet of the electronic mixing valve. A cold water bypass conduit extends between the cold water inlet conduit and the mixed water outlet conduit. A cold water bypass valve is on the cold water bypass conduit. A controller is configured to close the cold water bypass valve when a temperature measurement from a mixed water temperature sensor is less than a threshold temperature.

A storage type hot water supplying apparatus includes: a condenser having a refrigerant passage located at a hot water storage tank, the condenser being configured to condense refrigerant by exchanging heat between the refrigerant compressed by a compressor and water in the hot water storage tank; control circuitry configured to control a hot water storage operation, and a hot water supply detection sensor capable of detecting that a hot water supply operation is started, the hot water supply operation being an operation in which hot water in the hot water storage tank flows out of the hot water outlet and water flows into the hot water storage tank from the feed water inlet. The control circuitry is configured to increase an opening degree of the expansion valve when the hot water supply operation is started during the hot water storage operation.