A multi-air conditioner may comprise: an outdoor unit; a plurality of indoor units; a header module including an inlet pipe, branching to supply a refrigerant compressed by the outdoor unit, and a collection pipe for heat-exchanging the refrigerant by the plurality of indoor units collected at the outdoor unit; and connection kits detachably coupled between the header module and the plurality of indoor units. The connection kit may include: a connection inlet pipe; a connection collection pipe; connection regulating valves provided at the connection inlet pipe and the connection collection pipe to suppress the refrigerant from being supplied to the plurality of indoor units; and a connection bypass portion connecting the connection inlet pipe and the connection collection pipe to bypass, to the connection collection pipe, the refrigerant flowing into the connection inlet pipe.

An air conditioner, including a first compressor that compresses refrigerant; a second compressor that compresses the refrigerant; an indoor heat exchanger that performs heat exchange between the refrigerant and air; a first four-way valve connected to the first compressor; a first outdoor heat exchanger connected to the first four-way valve; a first valve connected to the first four-way valve; a second four-way valve connected to the second compressor; a second outdoor heat exchanger connected to the second four-way valve; a second valve connected to the second four-way valve; a first valve pipe that connects the first four-way valve and the second four-way valve; a second valve pipe that connects the first valve and the second valve; and a third four-way valve connected to the first valve pipe, the second valve pipe, the first compressor and the second compressor, and the indoor heat exchanger.

An HVAC system includes a first indoor heat exchanger coupled to an outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first circulation fan is positioned to circulate air around the first indoor heat exchanger and a second circulation fan is positioned to circulate air around the second indoor heat exchanger. A zone controller is coupled to the first indoor heat exchanger and configured to measure a temperature in the first zone, compare the measured temperature to a setpoint temperature of the first zone, and responsive to a difference between the measured temperature and the setpoint temperature, adjust a speed of the first circulation fan independent the second circulation fan.

An air conditioning device according to an embodiment of the present invention includes: an outdoor unit including a plurality of outdoor heat exchangers and an outdoor fan that blows air to the plurality of outdoor heat exchangers; at least one indoor unit connected to the outdoor unit via a refrigerant pipe; and a control device that controls a rotation speed of the outdoor fan. The control device determines, when determining that the number of outdoor heat exchangers used is to be increased, the rotation speed of the outdoor fan such that a heat exchange amount of the outdoor heat exchanger after an increase in the number of outdoor heat exchangers used is equal to or lower than the heat exchange amount of the outdoor heat exchanger before the increase in the number of outdoor heat exchangers used.