An HVAC system having a fixed orifice expansion device coupled to an evaporator coil is provided. In one embodiment, an expansion device coupled to an evaporator coil includes a flow restrictor and an evaporator inlet manifold. The flow restrictor includes multiple fixed orifices aligned with the refrigerant distribution tubes to restrict flow of refrigerant from the evaporator inlet manifold into the refrigerant distribution tubes through the multiple fixed orifices. Additional systems, devices, and methods are also disclosed.

The air-conditioning apparatus includes: a refrigerant cycle circuit through which a heat source side refrigerant circulates; a plurality of heat medium cycle circuits through which a heat medium circulates, the plurality of heat medium cycle circuits including a plurality of use-side heat exchangers, the heat medium exchanging heat with the heat source side refrigerant of the refrigerant cycle circuit in intermediate heat exchangers; and a heat medium distribution device provided in one of the plurality of heat medium cycle circuits to which a plurality of the use-side heat exchangers are connected, the heat medium distribution device controlling flow rates of the heat medium of the plurality of use-side heat exchangers connected to the heat medium cycle circuit.

A heat pump system includes a compressor, indoor heat exchanger, outdoor heat exchanger, and expansion valve. A main flow control device fluidly couples a discharge line to the outdoor heat exchanger when the heat pump system is in a cooling mode, and fluidly couples the discharge line to the indoor heat exchanger when the heat pump system is in a heating mode. An intermediate heat exchanger is configured to receive working fluid from the outdoor heat exchanger in a cooling mode and from the indoor heat exchanger in a heating mode. The intermediate heat exchanger is configured to superheat or sub-cool a working fluid therein. A secondary flow control device is configured to control a directional flow of working fluid between the indoor heat exchanger, the outdoor heat exchanger and the intermediate heat exchanger. A controller is operably coupled to the main and secondary flow control devices.

An air-conditioning apparatus includes a heat medium system configured to control a flow rate of the heat medium supplied to the heat source unit side heat exchanger that exchanges heat between refrigerant and the heat medium, the heat medium system having at least one system of a heat medium conveyor, a heat medium flow rate adjuster, and a heat medium flow rate control device. In the air-conditioning apparatus, the operation of each of use-side heat exchangers is changed to a cooling operation or a heating operation in accordance with a control command, and a cooling and heating concurrent operation is performed. The refrigerant is caused to flow through the heat source unit side heat exchanger in accordance with the ratio of the total cooling capacity of the use-side heat exchangers to the total heating capacity of the use-side heat exchangers. The heat medium flow rate control device controls the flow rate of the heat medium supplied to the heat source unit side heat exchanger, using the temperature of the heat medium flowing into the heat source unit side heat exchanger and the temperature of the heat medium flowing from the heat source unit side heat exchanger.

An air-conditioning apparatus includes actuation control means including an actuation unit that sequentially opens heat medium flow switching devices or heat medium flow control devices on a one-by-one basis. The actuation control means performs control in such a manner that start time of driving of pumps is later than start of actuation of the heat medium flow switching devices and the heat medium flow control devices.

An air conditioning system may include an outdoor device disposed in an outdoor space, the outdoor device including a compressor and an outdoor heat exchanger, a plurality of indoor devices disposed in an indoor space, the plurality of indoor devices including an indoor heat exchanger, and a distributor that distributes and introduces a refrigerant into the plurality of indoor devices. The outdoor device may include an outdoor branch branched into a plurality of refrigerant paths, a first outdoor tube that extends from the outdoor branch to guide the refrigerant to a first heat exchanger of the outdoor heat exchanger, a second outdoor tube that extends from the outdoor branch to guide the refrigerant to a second heat exchanger of the outdoor heat exchanger, and a bypass tube that extends from the outdoor branch to allow the refrigerant to bypass the outdoor heat exchanger, thereby guiding the refrigerant to the compressor.

A flow rate of circulating water to a water heat exchanger is determined by multiplying, by a rated water flow rate, a ratio of an absolute value of a difference between a total operation capacity of each of indoor side heat exchangers serving as a heating load and a total operation capacity of each of indoor side heat exchangers serving as a cooling load to a total operation capacity of the water heat exchanger.

A refrigeration apparatus uses R32 as a refrigerant, and includes a compressor, a condenser, an expansion mechanism, an evaporator, an intermediate injection channel and a suction injection channel. The intermediate injection channel guides a part of the refrigerant flowing from the condenser toward the evaporator to the compressor, causing the refrigerant to merge with intermediate-pressure refrigerant of the compressor. The suction injection channel guides a part of the refrigerant flowing from the condenser toward the evaporator to the suction passage, causing the refrigerant to merge with low-pressure refrigerant sucked into the compressor.

To provide an air-conditioning apparatus that is safer and has small conveying power for such as water at the indoor unit side can be made small. It is characterized in that a compressor 10 and a heat source side heat exchanger 12 are accommodated in a heat source apparatus 1, an intermediate heat exchanger 15 and a pump 21 in a relay unit 3, a use side heat exchanger 26 in an indoor unit 2, respectively, and when a controller 60 makes the compressor 10 stop based on the thermo-off due to decrease in the heat load in the use side heat exchanger 26 or an operation stop instruction, the controller 60 makes the pump 21 stop after the compressor 10 is stopped or almost at the same time as the stop.

An air conditioner has a refrigerant circuit and a blower. A refrigerant flow path switching mechanism is configured to switch to a first switching state to allow refrigerant to flow through a reheater, a second expansion valve, and a cooler in this order in a refrigerant circuit. The refrigerant flow path switching mechanism is configured to switch to a second switching state to allow refrigerant to flow through the reheater, the second expansion valve, and the cooler in this order in the refrigerant circuit. The reheater and the cooler are configured to allow air blown by the blower to pass through the cooler and then pass through the reheater during either of the first switching state and the second switching state.