Patent attributes
Provided is an air-conditioning and hot water supply combination system capable of maintaining a high hot water supply capacity and achieving high efficiency even under high-temperature outside air conditions by appropriately controlling the degree of superheat and the degree of subcooling of a heat exchanger. In an air-conditioning and hot water supply combination system, when an evaporating pressure or an evaporating temperature calculated from the evaporating pressure reaches a first predetermined value or higher, the degree of superheat of a refrigerant on a low-pressure gas side of a subcooling heat exchanger or the degree of subcooling of the refrigerant on a high-pressure liquid side of the subcooling heat exchanger is controlled by the opening degree of a low-pressure bypass pressure reducing mechanism, such that the evaporating pressure or the evaporating temperature calculated from the evaporating pressure is less than or equal to the first predetermined value.