An air-conditioning apparatus includes a four-way valve, a first three-way valve and a second three-way valve each having a closed port, a compressor, an indoor heat exchanger, an expansion valve, a first outdoor heat exchanger, a second outdoor heat exchanger, a bypass expansion valve, a check valve, a discharge temperature sensor, an indoor pipe temperature sensor, an indoor temperature sensor, a current sensor, and a controller configured to detect switching failure at the four-way valve, the first three-way valve, and the second three-way valve. The controller is configured to detect switching failure at the four-way valve, the first three-way valve, or the second three-way valve by using the temperatures measured by the discharge temperature sensor, the indoor pipe temperature sensor, and the indoor temperature sensor and the current in consideration of an operation status.

A refrigeration cycle apparatus includes: a first four-way valve having first to fourth ports; a second four-way valve and a third four-way valve each having fifth to eighth ports; a compressor; a discharge pipe connecting a discharge port of the compressor and the first port; a suction pipe connecting a suction port of the compressor and the second port; a first high pressure pipe connecting the discharge pipe and the fifth ports; a second high pressure pipe connecting the third port and the first high pressure pipe; a first valve provided at the first high pressure pipe; a second valve provided at the second high pressure pipe; a low pressure pipe connecting the suction pipe and the sixth ports; a first outdoor heat exchanger connected with the seventh port of the second four-way valve; a second outdoor heat exchanger connected with the seventh port of the third four-way valve; and an indoor heat exchanger connected with the fourth port.

A refrigeration cycle apparatus includes: a compressor; an indoor heat exchanger; an outdoor heat exchanger including first and second outdoor heat exchangers; a bypass flow passage causing a discharge side of the compressor to communicate with the first or second outdoor heat exchanger; a flow control valve at the bypass flow passage; and a controller performing a heating operation in which the first and second outdoor heat exchangers operate as an evaporator and the indoor heat exchanger operates as a condenser and a simultaneous heating and defrosting operation in which part of refrigerant the compressor discharges is supplied to one of the first and second outdoor heat exchangers through the bypass flow passage, the other of the outdoor heat exchangers operates as an evaporator, the indoor heat exchanger operates as a condenser, and an upper limit frequency of the compressor changes to a value higher than in the heating operation.

A refrigeration cycle apparatus includes a first flow switch valve including first to fourth ports, a second flow switch valve and a third flow switch valve each including fifth to seventh ports, a compressor, a discharge pipe connecting a discharge port of the compressor and the first port, a first high pressure pipe connecting between the discharge pipe and the fifth ports, a bypass expansion valve provided at a part of the first high pressure pipe, the part extending, a first outdoor heat exchanger connected to the seventh port of the second flow switch valve, a second outdoor heat exchanger connected to the seventh port of the third flow switch valve, and a controller. The controller is configured to perform a differential pressure ensuring process, when switching the second flow switch valve or the third flow switch valve. In the differential pressure ensuring process, the controller is configured to set operation frequency of the compressor to a first frequency and set opening degree of the bypass expansion valve to a first degree if a first condition is not met, and set the operation frequency of the compressor to a second frequency which is higher than the first frequency or set the opening degree of the bypass expansion valve to a second degree which is larger than the first degree if the first condition is met.

An air conditioner includes a switching valve, a flow rate restricting portion and an on-off valve. The switching valve provided in a flow path between a compressor and an outdoor heat exchanger. The outdoor heat exchanger includes a heat exchange portion and a heat exchange portion. During heating operation, the switching valve causes a second connection port, a third connection port and a first connection port to communicate with one another. The flow rate restricting portion and the on-off valve are connected in series between an outlet and an inlet of the compressor during the heating operation, to bypass a part of refrigerant. During defrosting operation of the heat exchange portion, the switching valve is configured such that a fourth connection port and the second connection port communicate with each other, and the third connection port and the first connection port communicate with each other.

A refrigeration cycle apparatus includes: a first four-way valve having first to fourth ports; a second four-way valve and a third four-way valve each having fifth to eighth ports; a compressor; a discharge pipe connecting a discharge port of the compressor and the first port; a suction pipe connecting a suction port of the compressor and the second port; a first high pressure pipe connecting the discharge pipe and the fifth ports; a second high pressure pipe connecting the third port and the first high pressure pipe; a first valve provided at the first high pressure pipe; a second valve provided at the second high pressure pipe; a low pressure pipe connecting the suction pipe and the sixth ports; a first outdoor heat exchanger connected with the seventh port of the second four-way valve; a second outdoor heat exchanger connected with the seventh port of the third four-way valve; and an indoor heat exchanger connected with the fourth port.

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.

An air-conditioning apparatus includes a main circuit in which a compressor, a refrigerant flow switching device, a load side heat exchanger, a load side expansion device, and a plurality of heat source side heat exchangers are sequentially connected. When the plurality of heat source side heat exchangers are used as condensers, the first heat source side heat exchanger and the second heat source side heat exchanger are connected in series. When the plurality of heat source side heat exchangers are used as evaporators, the first heat source side heat exchanger and the second heat source side heat exchanger are connected in parallel. A distribution adjustment header on an inlet side of at least either the first heat source side heat exchanger or the second heat source side heat exchanger when the plurality of heat source side heat exchangers are used as evaporators.

Provided is a refrigeration apparatus in which adverse events caused by excess refrigerant can be suppressed even when defrosting is performed with some of a plurality of outdoor units designated as units to be defrosted. An air-conditioning apparatus is configured from a parallel connection of a first outdoor unit and a second outdoor unit, wherein when a second outdoor heat exchanger of the second outdoor unit is caused to function as an evaporator while a first outdoor heat exchanger of the first outdoor unit is caused to function as a condenser to defrost the first outdoor heat exchanger, a refrigerant circuit has a flow channel that supplies some of the refrigerant flowing out of the first outdoor heat exchanger to the second outdoor heat exchanger and a flow channel that supplies the rest of the refrigerant flowing out of the first outdoor heat exchanger to an indoor heat exchanger.

An air conditioner includes a switching valve, a flow rate restricting portion and an on-off valve. The switching valve provided in a flow path between a compressor and an outdoor heat exchanger. The outdoor heat exchanger includes a heat exchange portion and a heat exchange portion. During heating operation, the switching valve causes a second connection port, a third connection port and a first connection port to communicate with one another. The flow rate restricting portion and the on-off valve are connected in series between an outlet and an inlet of the compressor during the heating operation, to bypass a part of refrigerant. During defrosting operation of the heat exchange portion, the switching valve is configured such that a fourth connection port and the second connection port communicate with each other, and the third connection port and the first connection port communicate with each other.