An air conditioner includes an indoor unit, an outdoor unit, an outdoor expansion valve, an indoor expansion valve, and a controller. The controller executes first control and second control. The first control includes stopping cooling operation or heating operation if a first condition is satisfied during cooling operation or heating operation, and then starting cooling operation or heating operation if a second condition is satisfied. The first condition indicates that a heat load in a target space is low. The second condition relates to the heat load in the target space. The second control includes setting opening degrees of the outdoor expansion valve and the indoor expansion valve upon a start of cooling operation or heating operation according to the first control to be larger than opening degrees upon satisfaction of the first condition.

An internal temperature adjusting device includes a heat pump, an internal heat exchanger, and an external heat exchanger. The internal heat exchanger is configured to function as one of an evaporator or a condenser of the heat pump, and exchange heat between a heat medium and air inside the container. The external heat exchanger is configured to function as the other one of the evaporator or the condenser, and exchange heat between the heat medium and air outside the container. The external heat exchanger includes a plurality of heat exchanging members separated from each other. According to the internal temperature adjusting device, drainage of the external heat exchanger as a whole can be secured.

An air-conditioning apparatus includes a heat source unit, a plurality of indoor units, and a relay unit. The heat source unit includes a heat-source-side flow control valve connected to a heat-source-side heat exchanger, a bypass pipe connected in parallel to the heat-source-side heat exchanger, a bypass flow control valve provided in the bypass pipe, and a gas-liquid separating unit configured to, when refrigerant flows out to the high-pressure pipe, mix refrigerant in a liquid state flowing through the heat-source-side heat exchanger and refrigerant in a gas state flowing through the bypass pipe and cause mixed refrigerant to flow out to the high-pressure pipe, and configured to, when refrigerant flows in from the low-pressure pipe, separate the refrigerant flowing in from the low-pressure pipe into refrigerant in a liquid state flowing into the heat-source-side heat exchanger and refrigerant in a gas state flowing into the bypass pipe.

An air-conditioning apparatus includes at least one system including a heat-medium conveying device, a heat-medium flow regulator, and a heat-medium flow control device, as a heat medium system capable of regulating a flow rate of a heat medium supplied to a heat source device-side heat exchanger exchanging heat between refrigerant and the heat medium. The air-conditioning apparatus switches each of a plurality of use-side heat exchangers to a cooling operation or a heating operation in accordance with a control command to perform a cooling and heating simultaneous operation. The refrigerant is caused to flow through the heat source device-side heat exchanger depending on a ratio of a total cooling capacity and a total heating capacity of the plurality of use-side heat exchangers. The heat-medium flow control device controls the flow rate of the heat medium supplied to the heat source device-side heat exchanger based on a difference between the total cooling capacity and the total heating capacity of the plurality of use-side heat exchangers and a total operation capacity of the heat source device-side heat exchanger.

An air-conditioning apparatus includes a controller configured to control operations of an outdoor fan. The controller has a voltage acquisition unit configured to acquire drive voltages of the outdoor fan at set time intervals while the rotation speed of the outdoor fan is maintained at a reference rotation speed, a determination unit configured to determine whether or not an acquired drive voltage is equal to or greater than a lower limit threshold and less than an upper limit threshold, an extraction unit configured to calculate an evaluation value by extracting a drive voltage determined to be equal to or greater than the lower limit threshold and less than the upper limit threshold, and a defrosting determination unit configured to decide to defrost the outdoor heat exchanger if the calculated evaluation value is equal to or greater than an evaluation threshold.

A heat exchanger includes: a plurality of first heat transfer tubes, a plurality of second heat transfer tubes located on leeward side relative to the plurality of first heat transfer tubes, a first distribution unit connecting the first ends of the plurality of first heat transfer tubes and the third ends of the plurality of second heat transfer tubes. The first distribution unit includes a flow rate control unit configured to be capable of switching between a first state and a second state. In the first state, refrigerant flows in the plurality of first heat transfer tubes and the plurality of second heat transfer tubes. In the second state, in only the plurality of first heat transfer tubes, a flow rate of the refrigerant is smaller than a flow rate of the refrigerant in the first state.

An air conditioner having an outdoor unit provided with a compressor, an outdoor temperature sensor, an outdoor humidity recognition part, and a control part, wherein the outdoor temperature sensor is installed on the outdoor unit to sense outdoor temperature, wherein the outdoor humidity recognition part is installed on the outdoor unit to recognize outdoor humidity information, and wherein the control part controls an operation of the compressor based information sensed from the outdoor temperature sensor and the outdoor humidity recognition part, whereby when the outdoor temperature has a preset value, the control part determines target evaporation temperature such that the target evaporation temperature is decreased as outdoor humidity increases, and the control part drives the compressor at an operation frequency corresponding to the determined target evaporation temperature.

A heat-exchange ventilation device includes: a heater connection terminal to which an external connection heater is connected; a temperature sensor that measures a temperature of a supply air flow passing through an air supply passage; and a control unit that controls operations of an air supply fan and an air exhaust fan and turning-on and turning-off of the external connection heater based on a measurement result of the temperature sensor. The external connection heater is installed in an outdoor air-supply duct and heats a supply air flow flowing through the air supply passage into a heat exchanger. The air supply fan is operable at a plurality of intensities, and the control unit prohibits a state in which the air supply fan is operated at an intensity lower than an intensity set in advance and the external connection heater is turned on.

An air conditioner and a control method for the same, the air conditioner including an air conditioning unit including a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger; and a controller configured to obtain enthalpy of a refrigerant flowing in the air conditioning unit, obtain an air conditioning capacity using a circulation amount of the refrigerant and the obtained enthalpy of the refrigerant, obtain efficiency based on the obtained air conditioning capacity and supplied power, and control the air conditioning unit according to the obtained efficiency.

A refrigeration apparatus includes a compressor, first and second heat exchangers, first and second electric valves, a passage-switching valve, a supercooling heat exchanger, and a controller. The first and second valves are disposed in first and second refrigerant passages. The supercooling heat exchanger conducts heat exchange between refrigerant flowing through the first and second refrigerant passages. The controller transitions to a defrosting operation mode upon determining that frost has formed on the second heat exchanger during a heating operation mode. The controller executes a defrosting preparatory control and a defrosting control after the defrosting preparatory control during the defrosting operation mode. The controller switches the passage-switching valve during the defrosting control. The controller narrows the opening degree of the first electric valve and controls the opening degree of the second electric valve to a minimum opening degree during the defrosting preparatory control.