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 a heat exchanger so that refrigerant heat is contributed to the tank. The heat exchanger houses a phase change material. A controller controls operation of the water heating apparatus.

A heat source-side unit (10) includes a heat source-side circuit (11). The heat source-side circuit (11) includes a compression unit (20) including a lower-stage compression element (23) and a higher-stage compression element (21), an intermediate heat exchanger (17) disposed on a refrigerant path between the lower-stage compression element (23) and the higher-stage compression element (21), and a bypass passage (23c) connected to a suction pipe (23a) and a discharge pipe (23b) each connected to the lower-stage compression element (23). At startup of the compression unit (20), a first action is performed for stopping the lower-stage compression element (23) and operating the higher-stage compression element (21). This configuration thus suppresses occurrence of liquid compression at startup of a compressor.

The present disclosure relates to a heat pump system comprising an outdoor unit disposed in an outdoor space, a plurality of thermal load units supplied with cool air and hot air, and an intermediate unit disposed between the outdoor unit and the plurality of thermal load units, wherein the intermediate unit is connected to the outdoor unit through refrigerant pipes and connected to the plurality of thermal load units through thermal medium pipes.

To avoid decline in the efficiency of a compressor at a low load, a thermal storage air conditioner has a refrigerant circuit (11) which has a compressor (22), an outdoor heat exchanger (23), and an indoor heat exchanger (72) and performs a refrigeration cycle, and a thermal storage section (60) which has a thermal storage medium and exchanges heat between the thermal storage medium and a refrigerant of the refrigerant circuit (11). The thermal storage air conditioner performs a simple cooling operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and a cooling and cold thermal energy storage operation in which in the refrigerant circuit (11), the refrigerant is condensed in the outdoor heat exchanger (23) and evaporates in the indoor heat exchanger (72), and in which the thermal storage medium in the thermal storage section (60) is cooled by the refrigerant. The thermal storage air conditioner has an operation control section (100) which, if a rotational speed of the compressor (22) is slowed down to a predetermined lower reference value in the simple cooling operation, switches an operation of the thermal storage air conditioner from the simple cooling operation to the cooling and cold thermal energy storage operation to increase the rotational speed of the compressor (22).

In an air-conditioning apparatus, a heat source side heat exchanger, intermediate heat exchangers, and use side heat exchangers are formed in separate bodies respectively and adapted to be disposed at separate locations one another. In a heat medium circulation circuit where the intermediate heat exchanger and the use side heat exchanger are connected, temperature sensors are installed. An anti-freezing operation mode is provided in which, when the detection temperatures of the temperature sensors become equal to or lower than a set temperature Ts while a compressor or pumps are stopped, the heat medium is circulated to perform anti-freezing of the heat medium.

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, an expansion device, and a refrigerant flow path in at least one intermediate heat exchanger are connected by a refrigerant pipe, and a heat medium circuit in which a pump, a use-side heat exchanger, and a heat-medium flow path in the at least one intermediate heat exchanger are connected by a heat-medium conveying pipe, the heat medium circuit being configured to cause a heat medium to circulate therethrough. The at least one intermediate heat exchanger comprises a plurality of intermediate heat exchangers. The plurality of intermediate heat exchangers are operative in a heating only operation mode, a cooling only operation mode, and a cooling and heating mixed operation mode in which some of the intermediate heat exchangers serve as the condenser and others of the intermediate heat exchangers serve as the evaporator.

A refrigerant circuit includes a compressor operable to compress a refrigerant, an expansion valve, an outdoor heat exchanger, an indoor heat exchanger in a fresh air inlet to a conditioned space, a recovery heat exchanger in an extracted air outlet from the conditioned space, and a reversing valve operable to direct a direction of refrigerant flow between a cooling mode and a heating mode.

A heat source-side unit (10) includes a heat source-side circuit (11). The heat source-side circuit (11) includes a compression unit (20) including a lower-stage compression element (23) and a higher-stage compression element (21), an intermediate heat exchanger (17) disposed on a refrigerant path between the lower-stage compression element (23) and the higher-stage compression element (21), and a bypass passage (23c) connected to a suction pipe (23a) and a discharge pipe (23b) each connected to the lower-stage compression element (23). At startup of the compression unit (20), a first action is performed for stopping the lower-stage compression element (23) and operating the higher-stage compression element (21). This configuration thus suppresses occurrence of liquid compression at startup of a compressor.

Proposed a gas heat-pump system including: a compressor compressing refrigerant and discharging the compressed refrigerant; an engine providing a drive force to the compressor; a radiator that cools coolant which is heated while passing through the engine; an indoor heat exchanger causing heat exchange to occur between indoor air and the refrigerant and thus cooling or heating an indoor space; an outdoor heat exchanger condensing the refrigerant; a four-way valve switching a flow direction of the refrigerant in such a manner that the refrigerant discharged from the compressor flows to the outdoor heat exchanger in a cooling operation mode and flows to the indoor heat exchanger in a heating operation mode; and a hot-water storage tank causing the heat exchange to occur between stored water and the refrigerant, and thus cooling the refrigerant in the cooling operation mode and heating the refrigerant in the heating operation mode.

A refrigeration apparatus includes a refrigerant circuit having a heat exchanger, a housing that houses at least the heat exchanger and is provided with a suction port on an upstream side of the heat exchanger, and a filter attached to the suction port of the housing. The filter is configured to be held not to come into contact with the heat exchanger. When air containing oil mist flows to the heat exchanger via the filter, at least a part of an oil component in the air containing oil mist is trapped by the filter.