An outdoor unit includes at least one heat exchanger, a first motor including a first fan, a second motor including a second fan, an inverter that applies voltage to the first motor and the second for respectively, a connection switching unit that switches the voltage applied to the second motor between on and off, and a control unit that controls the inverter and the connection switching unit. The inverter is disposed closer to the first motor than to the second motor.

A controller for controlling an environmental condition of a building via building equipment includes a user interface configured to present information to a user, an air quality sensor configured to sense indoor air quality conditions, a communications interface configured to communicate with a server system and receive outdoor air quality data from the server system, and a processing circuit. The processing circuit is configured to generate indoor air quality data based on the sensed indoor air quality data conditions sensed by the air quality sensor, receive, via the communications interface, the outdoor air quality data from the server system, and generate one or more interfaces indicating the indoor air quality conditions and the outdoor air quality conditions based on the indoor air quality data and the outdoor air quality data and cause the user interface to display the one or more interfaces.

A heating, ventilation, and/or air conditioning (HVAC) system includes a compressor, a fan, an inverter configured to drive operation of the compressor, and a controller communicatively coupled to the fan and the inverter. The controller includes a tangible, non-transitory, computer-readable medium with computer-executable instructions that, when executed by processor circuitry, are configured to cause the processor circuitry to determine an operating parameter of the fan in response to an interruption in receiving communication signals from the inverter and operate the fan based on the operating parameter during the interruption.

The present disclosure relates to a heat exchanger and an air conditioner improving heat exchange ability by optimizing the number of high protrusions of a heat transfer tube and a height difference between the high protrusion and a low protrusion to increase the heat transfer performance of the heat transfer tube or reduce the pressure loss in the tube. An air conditioner includes the heat exchanger including a heat transfer tube configured to allow the refrigerant to flow, fins installed on the heat transfer tube, and fin collars forming an insertion hole through which the heat transfer tube is inserted and passes, and the fin collars is in contact with the heat transfer tube by tube expansion of the heat transfer tube. The heat transfer tube includes high protrusions disposed in a spiral shape with respect to a tube axis direction of the heat transfer tube, twenty one to twenty seven of the high protrusions being formed along a circumferential direction of the heat transfer tube, and low protrusions disposed between two of the adjacent high protrusions along the circumferential direction of the heat transfer tube and having a height lower by 0.03 mm to 0.05 mm than the high protrusions.

The present disclosure relates to a novel method for operating and controlling a vapor-compression cycle. The method of the present disclosure provides that a turbine-based expander in a heat pump model can achieve greater COP benefit in cooling than heating. Further, phase separation and an evaporator bypass are implemented within the turbine-based expander. Phase separation leads to successful energy recovery and compressor superheat control.

A system comprising a compressor, a first valve coupled to the compressor and to a first coil, a first expansion valve coupled to the first coil, and a second expansion valve. The second expansion valve coupled to a second coil. A second valve is coupled to the second coil and the compressor. A third valve is coupled to the compressor and a third coil. In response to receiving a heating demand that is below a threshold heating demand, a controller induces an artificial heating demand.

An air conditioner including a compressor, an outdoor heat exchanger, an expansion valve, an indoor heat exchanger, a first fan, a second fan, and a cooling/heating conversion device. The compressor is configured to compress a refrigerant and including a first compressor and a second compressor. The outdoor heat exchanger is configured to exchange heat of the refrigerant with outdoor air, and includes a first and second heat exchanger. The expansion valve is configured to expand a refrigerant. The indoor heat exchanger is configured to exchange heat of the refrigerant with indoor air. The first fan and the second fan correspond to the first heat exchanger and the second heat exchanger, respectively. The cooling/heating conversion device during a during a heating operation is connected in parallel to the first and second heat exchangers, and during a during a cooling operation is connected in series to the first and second heat exchangers.

In an air-conditioning apparatus in which air sucked into a casing of an outdoor unit by a fan is discharged from an upper portion of the casing, each of liquid header portions is configured to be connected with each of heat transfer tubes of a plurality of divided regions formed by dividing the outdoor heat exchangers in an up and down direction. Further, a shunt is configured to supply two-phase refrigerant, in which quality is adjusted by a gas-liquid separator, to each of the liquid header portions. To each of the liquid header portions, the shunt supplies the two-phase refrigerant of the amount corresponding to the air quantity of the divided region connected to each of the liquid header portions.

An air conditioner 1 includes: an outdoor heat exchanger 14; an outdoor fan 12 for blowing air to the outdoor heat exchanger; an outdoor fan motor 20 that drives the outdoor fan; an outdoor fan inverter 21 that drives the outdoor fan motor; and a control unit 31 that generates a rotation-speed command voltage for controlling the rotation number of the outdoor fan motor. In addition, the control unit starts a defrost operation of the outdoor heat exchanger, based on the rotation-speed command voltage. In this manner, it is possible to achieve an outdoor device of an air conditioner in which there is no need to provide a current detecting sensor, and it is possible to detect frost formation over the heat exchanger during a heating operation and to perform a defrost operation at low costs.

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.