An air-conditioning apparatus, including: a heat source-side heat exchanger including a plurality of heat transfer tubes each having a flattened shape and being arranged in parallel, the heat source-side heat exchanger being used at least as a condenser of a refrigeration cycle; and an outdoor fan for generating flows of air passing through the heat source-side heat exchanger in a predetermined air velocity distribution. The heat source-side heat exchanger is configured to exchange heat between the air and refrigerant flowing through the heat transfer tubes and includes a plurality of refrigerant paths, each including at least one of the plurality of heat transfer tubes and a plurality of two-phase paths for allowing gas refrigerant to flow into and out as two-phase refrigerant; and a plurality of liquid-phase paths for allowing the two-phase refrigerant flowing out of the plurality of two-phase paths to flow out as subcooled liquid refrigerant.

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 system includes a compressor, an indoor fan, a thermostat, an indoor fan controller, and a compressor controller. The thermostat provides first and second signals based on indoor loading. The fan controller operates the fan in low speed mode and the compressor controller operates the compressor in low capacity mode when only the first signal is asserted. The compressor controller automatically switches the compressor to high capacity mode if only the first signal remains asserted past the low capacity mode runtime. The fan controller operates the fan in high speed mode when the second signal is asserted while the first signal is still asserted. The compressor controller continues to operate the compressor in high capacity mode and the fan controller operates the fan in low speed mode after the second signal is de-asserted, until the first signal is de-asserted, at which point the fan and compressor are turned off.

A refrigeration cycle apparatus includes a refrigerant circuit, a high-side pressure sensor, an outside air temperature sensor, an outdoor fan, a fan driving unit, and a controller. The controller includes a pressure prediction unit that predicts, based on a high-side pressure detected by the high-side pressure sensor, a predicted value of high-side pressure at the elapse of a set time, a fan rotation speed control unit that, during cooling operation in which an indoor heat exchanger acts as an evaporator, adjusts the rotation speed of the fan driving unit based on the outside air temperature detected by the outside air temperature sensor and the operating capacity of an indoor unit, and an intermittent fan control unit that, if the fan driving unit is running at a set lower limit rotation speed, and if the high-side pressure is below a target value, controls the fan driving unit to perform intermittent operation, the intermittent operation being performed by setting an ON time and an OFF time such that the predicted value predicted by the pressure prediction unit approaches the target value.

A heat exchanger includes: a plurality of flat pipes each having flat surfaces directed upward and downward, wherein the flat pipes are arranged in an up-down direction and extend in a fin stacking direction intersecting an air flow direction; and a plurality of heat transfer fins stacked in the fin stacking direction and each including: a plurality of cutouts into which the flat pipes are inserted, respectively, wherein the cutouts extend from a leeward side toward a windward side in the air flow direction; a plurality of fin main parts each formed between the cutouts adjacent to each other in the up-down direction; a fin windward part continuously extending from the fin main parts in the air flow direction toward the windward side of the cutouts; and a fin collar part extending from a peripheral portion of each of the cutouts toward one side in the fin stacking direction.

A heat exchanger, connected to a refrigerant pipe, includes: heat transfer tubes; and a header that connects the refrigerant pipe and the heat transfer tubes, and that forms a refrigerant flow path between the refrigerant pipe and the heat transfer tubes. The header includes a first member that includes a first plate-shaped portion, and a second member that includes a second plate-shaped portion that is stacked on a heat transfer tubes side of the first plate-shaped portion. The first plate-shaped portion has a first opening that forms the refrigerant flow path. The second plate-shaped portion has a second opening that forms the refrigerant flow path. When viewed in a stacking direction of the first plate-shaped portion and the second plate-shaped portion, the second opening and the first opening overlap each other at a first region and at a second region that is different from the first region.

An air conditioner includes a refrigerant circuit, sensors that measure an amount representing a state of refrigerant in the refrigerant circuit, and a controller. The controller executes normal operation according to air conditioning load and a first detection operation of detecting refrigerant leakage. The controller adjusts a degree of subcooling at an outlet of the condenser to a first value during normal operation. The controller detects a value related to discharge temperature of the compressor or a value related to degree of superheating at an outlet of the evaporator, based on a sensor measurement result. The controller adjusts degree of subcooling to a second value larger than the first value when executing the first detection operation, and determines that refrigerant is leaking when the value related to discharge temperature of the compressor or the value related to degree of superheating is equal to or larger than a threshold value.

A refrigerant leakage notifying device includes a refrigerant sensor, a determination unit, a notification unit, and an output unit. The refrigerant sensor detects a refrigerant and outputs a detection signal according to a detection result. The determination unit receives the detection signal outputted from the refrigerant sensor and determines leakage of the refrigerant in accordance with the detection signal received. The notification unit notifies leakage of the refrigerant with at least one of sound and light in a case in which the determination unit has determined that the refrigerant is leaking. The output unit is provided separately from the refrigerant sensor. The output unit outputs a test signal to the determination unit. The test signal is a signal that the determination unit has determined that the refrigerant is leaking in a case in which the determination unit receives the signal.

An air-conditioning system includes a heat source unit, an air conditioner connected via piping to the heat source unit and configured to perform heat exchange between water supplied by the heat source unit and indoor air, a water circulation device for circulating the water between the heat source unit and the air conditioner, and an air-conditioning control device. The air-conditioning control device controls the heat source unit to lower temperature of the water flowing into the air conditioner, in accordance with an increase in an indoor humidity, and controls the water circulation device to lower temperature of the water flowing from the air conditioner back to the heat source unit, in accordance with an increase in an indoor temperature.

A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.