An air conditioning indoor unit that blows air, which has exchanged heat with a refrigerant flowing through a heat exchanger, into an air conditioning target space, includes: a liquid refrigerant pipe and a gas refrigerant pipe that are connected to the heat exchanger; a casing that accommodates the heat exchanger and that has an opening communicating with the air conditioning target space; a first shutoff valve in the liquid refrigerant pipe; a second shutoff valve in the gas refrigerant pipe; and a partition wall that separates a first space from a second space in the casing. The first shutoff valve and the second shutoff valve are in the first space. The second space communicates with the air conditioning target space via the opening.

An air conditioning apparatus includes a refrigerant circuit, and includes a connecting portion, a circuit configuration portion, a first member, and a controller. To the connecting portion: a first electric wire connected to a first device of a plurality of safety devices including at least two types of a refrigerant detector, an alarm device, an isolation valve, and a ventilation device; and a second electric wire connected to a second device of a type different from the first device of the plurality of safety devices are connected. The circuit configuration portion forms an interlock circuit together with the first electric wire and the second electric wire connected to the connecting portion. The first member enables formation of a first circuit including at least part of the circuit configuration portion without going through the first electric wire and the second electric wire. The controller prohibits an operation of the air conditioning apparatus w % ben no current flows through either the interlock circuit or the first circuit.

An air-conditioning apparatus includes a refrigeration circuit, a first shut-off device, a leakage detection device, and a controller configured to perform a refrigerant recovery operation in a case where refrigerant leakage is detected. At the time of the refrigerant recovery operation, the controller performs control to perform a first operation of recovering refrigerant from a load-side heat exchanger into an accumulator and a heat-source-side heat exchanger, and a second operation of moving refrigerant in the heat-source-side heat exchanger to the accumulator. In the first operation, the first shut-off device is closed, a flow passage switching device is brought into a first connection state, and a compressor is driven. The second operation is performed after the first operation, and in the second operation, the connection state of the flow passage switching device is switched to a second connection state in a state where the compressor is being operated.

An air-conditioner which performs an appropriate control in the event of a leak of refrigerant. The air-conditioner includes a refrigerant circuit, a refrigerant leak sensor which senses a leak of refrigerant in the refrigerant circuit, an indoor fan which delivers air to the indoor heat exchanger, and an indoor control circuit which, upon sensing a leak of refrigerant by the refrigerant leak sensor, controls the indoor fan based on whether the refrigerant sealed in the refrigerant circuit is flammable.

A valve system includes a motor, a first valve, a second valve, and a controller. The first valve is connected to the motor shaft and is rotatable to an open position, in which fluid flows through a first channel, and a close position, in which fluid is prevented from flowing through the first channel. The second valve is connected to the motor shaft and is rotatable to an open position, in which fluid flows through a second channel from a first end to a second end, and to a close position, in which fluid is prevented from flowing through the second channel. The controller is connected to the motor and can sequentially actuate the first valve and the second valve to create at least a first, second, third, and fourth position.

A multi-air conditioner for heating and cooling may include at least one indoor unit installed in an indoor space and comprising an indoor heat exchanger and an indoor expansion valve; an outdoor unit connected to the at least one indoor unit via a refrigerant pipeline and comprising an outdoor heat exchanger, a compressor, an outdoor expansion valve, and a four-way valve; and at least one leak shut-off valve provided on the refrigerant pipeline, that blocks a flow of refrigerant in the refrigerant pipeline when a refrigerant leak from the refrigerant pipeline occurs in the indoor space. The outdoor unit may decrease a pressure of the refrigerant pipeline when a refrigerant leak occurs from the refrigerant pipeline. Therefore, it is possible to minimize an amount of refrigerant leakage when there is a refrigerant leak in the indoor space.

A valve system includes a motor, a first valve, a second valve, and a controller. The first valve is connected to the motor shaft and is rotatable to an open position, in which fluid flows through a first channel, and a close position, in which fluid is prevented from flowing through the first channel. The second valve is connected to the motor shaft and is rotatable to an open position, in which fluid flows through a second channel from a first end to a second end, and to a close position, in which fluid is prevented from flowing through the second channel. The controller is connected to the motor and can sequentially actuate the first valve and the second valve to create at least a first, second, third, and fourth position.

A transport refrigeration unit (13) is provided and includes a wall (510) defining an inlet (511) and an outlet (512) and a pod (530) attachable to the wall (510) to define, with a portion of the wall, an interior configured to accommodate a heat exchange portion of a heat exchanger (520), a fan (550) that drives air flow from the inlet (511) and to the outlet (512) through the heat exchange portion. The pod (530) is configured to isolate coolant flow control elements (522) of the heat exchanger (520) from the interior.

A CO.sub.2 refrigeration system, includes a receiving tank, a condenser, a low temperature system, and a medium temperature system. The low temperature system is fluidly coupled to the receiving tank and the condenser. The low temperature system includes a plurality of low temperature evaporators, a plurality of low temperature expansion valves, a plurality of low temperature compressors, and a plurality of flexible low temperature conduits fluidly coupling the low temperature compressors to a low temperature discharge header and a low temperature suction header. The medium temperature system is fluidly coupled to the receiving tank and the low temperature system. The medium temperature system includes a plurality of medium temperature evaporators, a plurality of medium temperature expansion valves, a plurality of medium temperature compressors, and a plurality of flexible medium temperature conduits fluidly coupling the medium temperature compressors to a medium temperature discharge header and a medium temperature suction header.

In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and a valve coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine that the outdoor heat pump unit is in operation during an air conditioning cycle. The controllers are further operable to determine an outdoor temperature and compare the outdoor temperature to a predetermined temperature. The controllers are further operable to initiate a closure of the valve coupled to the refrigerant line and initiate operation of the compressor at an end of the air conditioning cycle to pump down a refrigerant to the outdoor coil in response to comparing the outdoor temperature to the predetermined temperature.