A channel on an upstream side of a third expansion device and a channel on an upstream side of a second expansion device are connected during a heating operation, and medium pressure refrigerant generated by the third expansion device during the heating operation is introduced on a suction side of a compressor via the second expansion device and a suction injection pipe.

An outdoor unit includes a compressor compressing a sucked refrigerant and discharging compress, an outdoor heat exchanger exchanging heat between outdoor air and the refrigerant, an accumulator storing a liquefied refrigerant at a suction side of the compressor, a solenoid valve for storing the refrigerant in the outdoor heat exchanger, and a controller performing control so as to feed the refrigerant stored within the outdoor heat exchanger during a defrosting operation, to the accumulator on the basis of an amount of refrigerant within the accumulator when operation is switched to a heating operation from the defrosting operation.

A refrigeration system includes a receiver, a gas bypass valve, a parallel compressor, and a controller. The gas bypass valve and the parallel compressor are fluidly coupled to an outlet of the receiver in parallel and configured to control a pressure of a gas refrigerant in the receiver. The controller is configured to switch from operating the gas bypass valve to operating the parallel compressor to control the pressure of the gas refrigerant in the receiver in response to a value of a process variable crossing a switchover setpoint. The value of the process variable depends on an amount of the gas refrigerant produced by the refrigeration system. The controller is configured to automatically adjust the switchover setpoint in response to the amount of the gas refrigerant produced by the refrigeration system being insufficient to sustain operation of the parallel compressor.

An air-conditioning apparatus that includes a compressor, a flow switching device, an outdoor heat exchange unit, an expansion section and an indoor heat exchanger, which are connected by pipes, in which the outdoor heat exchange unit includes a first outdoor heat exchanger, a first flow rate control device, a second outdoor heat exchanger, a second flow rate control device, a bypass pipe, the second outdoor heat exchanger, the second flow rate control device, a third flow rate control device, and a flow control device.

In a refrigeration cycle apparatus according to the present invention, a non-azeotropic refrigerant mixture is used. The refrigeration cycle apparatus includes a compressor, a first heat exchanger, a decompressor, a second heat exchanger, a third heat exchanger, and a blower. The blower blows air to the second heat exchanger and the third heat exchanger. The non-azeotropic refrigerant mixture circulates in a first circulation direction through the compressor, the first heat exchanger, the decompressor, the second heat exchanger, and the third heat exchanger. The second heat exchanger is greater in flow path resistance than the third heat exchanger. The blower forms a parallel flow with the non-azeotropic refrigerant mixture that flows through the second heat exchanger and the third heat exchanger.

A method of operating an air conditioner unit, as provided herein, includes initiating a first heat pump cycle, the first heat pump cycle comprising sending a control signal to the fan to rotate at a predetermined rotational speed, and detecting an actual rotational speed of the fan, calculating a first flow rate of air through the first heat exchanger based on the control signal and the actual rotational speed, storing the first flow rate as a first reference flow rate, stopping the first heat pump cycle, initiating a second heat pump cycle, calculating a second flow rate of air through the first heat exchanger, comparing the calculated second flow rate to the first reference flow rate, and directing the air conditioner unit based on the comparison of the calculated second flow rate to the first reference flow rate.

Provided is a refrigerant cycle apparatus capable of suppressing detects caused by iodine even when a refrigerant containing iodine is used. An air conditioner includes a refrigerant circuit through which a refrigerant containing iodine circulates. The refrigerant circuit includes a component that is in contact with a refrigerant containing iodine, the component being made of metal other than aluminum or an aluminum alloy, or having a content of aluminum which is equal to or less than a ratio at which corrosion of aluminum occurs by iodine. The component is at least one of a component of a compressor, a component of a heat-source-side heat exchanger or a utilization-side heat exchanger, a component of an expansion valve, a drier, and a connection pipe.

An air conditioning and ventilating system S including: an air conditioning device A including a heat exchanger 22 configured to generate conditioned air by heat exchange with a refrigerant, and configured to send the conditioned air to an air conditioned space R; a ventilation device 30 configured to ventilate the air conditioned space R; a refrigerant sensor 24 configured to detect concentration of the refrigerant in the air conditioned space R; and a control unit 40 configured to control operations of the air conditioning device A and the ventilation device 30. On determination that the refrigerant concentration acquired from the refrigerant sensor 24 exceeds a first predetermined value, the control unit 40 sets an operation of a compressor 13 of the air conditioning device A to a stop state and sets the ventilation device 30 to an operating state. On determination that the refrigerant concentration that has exceeded the first predetermined value becomes equal to or less than the first predetermined value, the control unit 40 continues the stop state of the compressor 13 of the air conditioning device A and the operating state of the ventilation device 30 until predetermined timing.

An apparatus evaluation system includes a first evaluation unit that evaluates a first air conditioning apparatus, and a first air conditioning control unit that controls a second air conditioning apparatus. The first evaluation unit performs a first evaluation process to evaluate the first air conditioning apparatus based on a first evaluation index obtained in a first operation performed as a first evaluation operation at a time of installation, and a second evaluation process to evaluate the first air conditioning apparatus based on the first evaluation index obtained in a second operation performed as the first evaluation operation after the first evaluation process. The control unit operates the second air conditioning apparatus before at least one of the first and second operations of the first air conditioning apparatus is performed, and/or while at least one of the first and second operations of the first air conditioning apparatus is being performed.

An air-conditioning apparatus including heat source apparatuses each including a compressor and an accumulator includes: a refrigerant amount calculation unit that calculates an amount of the refrigerant accumulated in the accumulator in one of the heat source apparatuses that is to be controlled; a refrigerant differential amount calculation unit configured to calculate, when the number of the heat source apparatuses is two, a differential amount between the calculated amount and an amount of the refrigerant in the accumulator in the other heat source apparatus, and calculate, when the number of the heat source apparatuses is three or more, a differential amount between the calculated amount of the refrigerant and an average amount of amounts of the refrigerant accumulated in the accumulators in the heat source apparatuses; and a liquid equalization control unit that controls the heat source apparatus to be controlled, based on the calculated differential amount.