A refrigeration cycle apparatus includes a refrigeration circuit in which non-azeotropic refrigerant mixture circulates. The refrigeration circuit includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, an expansion valve, and a four-way valve. The four-way valve is configured to assume a first state and a second state. The outdoor heat exchanger includes a plurality of refrigerant flow paths and a linear flow path switching valve configured to switch connections of the plurality of refrigerant flow paths between a series state in which the non-azeotropic refrigerant mixture flows through the plurality of refrigerant flow paths in series and a parallel state in which the non-azeotropic refrigerant mixture flows through the plurality of refrigerant flow paths in parallel. A controller switches the linear flow path switching valve between the series state and the parallel state when a multi-way valve is in the second state.

An air conditioner unit includes a compressor, an exterior coil, a main interior coil, a main expansion device, a reheat interior coil and a reheat expansion device. The reheat interior coil is positioned adjacent the main interior coil. The main expansion device is connected in series between the exterior coil and the main interior coil, and the reheat expansion device is connected in series between the main expansion device and the reheat interior coil. A reheat valve is operable to selectively adjust a flow direction through the reheat interior coil. The reheat valve is a four-way valve, and one port of the four-way valve is blocked.

A system for air-conditioning and hot-water supply is configured to selectively perform a cooling operation and a heating operation. The system includes: an outdoor unit having a compressor and an outdoor heat exchanger; at least one or more indoor units each of which is connected to the outdoor unit and includes an indoor heat exchanger; a hot-water supply unit connected to the outdoor unit so as to be arranged in parallel to the at least one or more indoor units and including a refrigerant-water heat exchanger; and a controller configured to monitor an occurrence of a request for hot-water supply from the hot-water supply unit during the cooling operation performed at at least one of the indoor units, and then to start the heating operation. The controller is further configured to determine a time point to resume the cooling operation based on at least one of an outdoor temperature and a target temperature of at least one indoor unit in the heating operation.

An air conditioner performs a heating operation and a cooling operation with enhanced heat exchange performance and also performs a heating continuous operation, while preventing increases in manufacturing cost and packaging volume. An air conditioner comprises a refrigerant circuit through which refrigerant circulates. A second heat exchanger includes a first refrigerant flow path and a second refrigerant flow path. A first port of the flow path switching device is connected to a discharge portion of a compressor. A second port is connected to a first heat exchanger. A third port is connected to an intake portion of the compressor. A fourth port is connected to a pipe that connects a branch point to the first refrigerant flow path. A fifth port is connected to the second refrigerant flow path. A sixth port is connected to the first refrigerant flow path.

When a refrigerant amount balance control is executed, in indoor units where the refrigerant supercooling degree is lower than an average refrigerant supercooling degree, the refrigerant pressure on a downstream side of indoor expansion valves decreases since the degrees of opening of the valves are decreased. On the other hand, in an indoor unit where the refrigerant supercooling degree is higher than the average refrigerant supercooling degree, although the degrees of opening of the valves are made high, the refrigerant pressure on the downstream side of the valves decreases and this decreases the refrigerant pressure on the downstream side of the indoor expansion valve, so that the difference in pressure between on the upstream side and on the downstream side of the indoor expansion valve increases and the liquid refrigerant staying at an indoor heat exchanger of the indoor unit consequently flows out into a liquid pipe.

A heat pump system, a defrosting method for the heat pump system, and a controller. The heat pump system includes a heat exchanger assembly for exchanging heat with a fluid medium, the heat exchanger assembly comprised a first heat exchanger and a second heat exchanger arranged in parallel, the second heat exchanger being arranged upstream of the first heat exchanger in the flow direction of the fluid medium, and when the heat pump system is operating in a heating mode and the temperature and/or ambient humidity to which the heat exchanger assembly is currently exposed reach a pre-set value, the second heat exchanger and the first heat exchanger function as a condenser and an evaporator, respectively.

Provided is a refrigeration cycle apparatus configured to perform a heating operation and a simultaneous heating and hot-water supply operation. The refrigeration cycle apparatus is configured to execute an operation mode circulating refrigerant through, in order, a discharge outlet of a compressor, a first heat exchanger, an expansion device, a second heat exchanger provided to a water tank, and a suction inlet of the compressor, and causing the refrigerant flowing through the second heat exchanger to evaporate by heat generated by a heat source provided to the water tank.

When a refrigerant amount balance control is executed, in indoor units where the refrigerant supercooling degree is lower than an average refrigerant supercooling degree, the refrigerant pressure on a downstream side of indoor expansion valves decreases since the degrees of opening of the valves are decreased. On the other hand, in an indoor unit where the refrigerant supercooling degree is higher than the average refrigerant supercooling degree, although the degrees of opening of the valves are made high, the refrigerant pressure on the downstream side of the valves decreases and this decreases the refrigerant pressure on the downstream side of the indoor expansion valve, so that the difference in pressure between on the upstream side and on the downstream side of the indoor expansion valve increases and the liquid refrigerant staying at an indoor heat exchanger of the indoor unit consequently flows out into a liquid pipe.

An outdoor unit of an air-conditioner and two-pipe and three-pipe air-conditioning systems having the same are provided. The outdoor unit includes a compressor defining an outlet and an inlet; a first four-way valve defining a first valve communicated with the outlet, second and third ports communicated with the inlet; a second four-way valve defining second and third ports communicated with the inlet; an outdoor heat exchanger defining a first refrigerant valve Communicated with the fourth port of the first four-way valve; a first gas pipe defining a first end connected with the second and third ports of the first and second four-way valves and, the inlet; a second gas pipe defining a first end connected with the fourth port of the second four-way valve; a third gas pipe defining a first end connected with the outlet and a second end connected with the first port of the second four-way valve.

A combined air-conditioning and hot-water supply system that, if a temperature that is set in a hot-water supply unit is higher than a temperature of refrigerant discharged from a compressor when the combined air-conditioning and hot-water supply system is in a heating operation cycle state, increases a target condensing temperature of an outdoor unit above the target condensing temperature that has been set, and controls an opening degree of an indoor expansion device to be less than the opening degree that has been set, such that a heating load of an indoor unit is maintained constant.