Abstract: A refrigeration cycle apparatus includes a first refrigerant circuit and a second refrigerant circuit so as to improve the efficiency of operations. A first refrigerant circuit using a first refrigerant having a pressure of 1.2 MPa or less at 30° C. and a second refrigerant circuit using a second refrigerant having a pressure of 1.5 MPa or more at 30° C. are provided, and a dual cycle operation in which the first refrigerant circuit and the second refrigerant circuit are simultaneously operated to exchange heat between the first refrigerant and the second refrigerant and a single cycle operation in which the first refrigerant circuit is operated without operating the second refrigerant circuit to perform a cooling operation or heating operation are enabled in a switchable manner.

Abstract: A water heating system includes: a refrigerant circuit that includes a compressor and in which a refrigerant flows; and a water circuit in which water flows. The refrigerant circuit shares with the water circuit a water heat exchanger that heats the water using the refrigerant discharged from the compressor. The water heat exchanger includes a first heat-exchanging unit in which the refrigerant exchanges heat with the water at a water outlet portion. The refrigerant circuit further includes a heat radiator that is disposed between the compressor and the first heat-exchanging unit and that radiates heat of the refrigerant discharged from the compressor. The heat radiator is configured to radiate heat of the refrigerant to water that flows on an upstream side of the water outlet portion.

Abstract: A hot water supply system includes a hot water supply apparatus, a plurality of supply paths, and an estimation unit. The hot water supply apparatus includes a heating apparatus configured to heat water, a tank configured to store the water heated by the heating apparatus, and a water circuit configured to circulate the water in the tank. Each supply path is coupled to a corresponding one of a plurality of hot water supply targets and is configured to supply the water from the tank. The estimation unit is configured to predict a total amount of hot water supply demand, based on time-series data of a first index that indicates an amount of heat of water used in each of the plurality of hot water supply targets.

Abstract: A hot water supply apparatus includes: a first channel configured to send water in a medium-temperature layer (M) to a heating section; and a second channel configured to return water heated by the heating section to a tank. The second channel has an outflow port at a lower position than an inflow port of the first channel.

Abstract: A controller performs a first operation in which a heat source device directly or indirectly heats water in a first channel of a heat exchanger and a second operation in which the heat source device directly or indirectly cools the water in the first channel of the heat exchanger after the first operation ends.

Abstract: A water heating system includes: a refrigerant circuit that includes a compressor and in which a refrigerant flows; and a water circuit in which water flows. The refrigerant circuit shares with the water circuit a water heat exchanger that heats the water using the refrigerant discharged from the compressor. The water heat exchanger includes a first heat-exchanging unit in which the refrigerant exchanges heat with the water at a water outlet portion. The refrigerant circuit further includes a heat radiator that is disposed between the compressor and the first heat-exchanging unit and that radiates heat of the refrigerant discharged from the compressor. The heat radiator is configured to radiate heat of the refrigerant to water that flows on an upstream side of the water outlet portion.

Abstract: A hot water supply apparatus includes a heat exchanger that heats water for hot water supply, a pressure controller provided in a subsequent stage of the heat exchanger, and a trap that promotes deposition of scale. The pressure controller pressurizes the water for hot water supply. The trap is provided in a subsequent stage of the pressure controller.

Abstract: A controller performs a first operation in which a heat source device directly or indirectly heats water in a first channel of a heat exchanger and a second operation in which the heat source device directly or indirectly cools the water in the first channel of the heat exchanger after the first operation ends.