Disclosed is an air conditioner and control method thereof. The air conditioner and control method thereof is to improve rapid heating performance without using a large-capacity compressor. The air conditioner includes an indoor unit having a first heat exchanger, an outdoor unit having a compressor and a second heat exchanger, a refrigerant cycle configured to form a refrigerant circulation path between the indoor unit and the outdoor unit, a flow path switch configured to switch a flow of a refrigerant in the refrigerant cycle, and a controller configured to control the flow path switch to allow one part of the refrigerant discharged from the compressor to flow into an inlet of the compressor and the other part of the refrigerant discharged from the compressor to flow into at least one of the first heat exchanger and the second heat exchanger.

Provided is a refrigeration cycle apparatus capable of achieving an improvement in heat exchange performance during a heating operation and during a cooling operation, while suppressing increases in manufacturing cost and volume required for packaging. The outdoor heat exchanger and the outdoor heat exchanger are connected in parallel to the indoor heat exchanger via the branch portion. The flow path switching device includes a first port, a second port, and a third port. The first port is connected with a third refrigerant flow path. The second port is connected with the outdoor heat exchanger. The third port is connected with a fourth refrigerant flow path. The second port is configured to switch between a state in which the second port is connected to the first port and a state in which the second port is connected to the third port.

To improve the heat exchange efficiency of a heat exchanger that includes an upstream heat exchange unit and a downstream heat exchange unit. When the heat exchanger functions as an evaporator, a gas outlet pipe is an upstream refrigerant outlet that is located adjacent to the other end of upstream flat pipes of the upstream heat exchange unit, and a gas outlet pipe is a downstream refrigerant outlet that is located adjacent to the other end of downstream flat pipes of the downstream heat exchange unit. First resistance to refrigerant flow in the upstream heat exchange unit and second resistance to refrigerant flow in the downstream heat exchange unit are adjusted in order that the degree of superheating of refrigerant at the downstream refrigerant outlet is smaller than the degree of superheating of refrigerant at the upstream refrigerant outlet.

A refrigeration cycle apparatus includes a refrigerant circuit that is formed by connecting a compressor, a flow passage switching device, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger via pipes, and through which refrigerant flows, an outdoor air-sending device configured to blow outdoor air to the outdoor heat exchanger, an outdoor air temperature detector configured to detect a temperature of the outdoor air, and a controller configured to control an operation of the outdoor air-sending device.

Disclosed is a system for independently controlling the climate within a primary zone and at least one secondary zone of a building. The system comprises a primary packaged unit comprising a primary indoor coil and a primary variable speed indoor fan blowing over the primary indoor coil to serve the primary zone of the building. The system further comprises a secondary unit comprising a secondary indoor coil circulating the refrigerant and a secondary variable speed indoor fan blowing over the secondary indoor coil to serve a secondary zone of the building. The primary unit and the at least one secondary unit shares a common variable speed compressor, outdoor coil, and an outdoor fan that are disposed within the primary unit. First and second solenoid valves in the primary unit selectively control refrigerant flow to the primary and secondary units to enable independent control of the zones.

In an air-conditioning apparatus, a heat source side heat exchanger, intermediate heat exchangers, and use side heat exchangers are formed in separate bodies respectively and adapted to be disposed at separate locations one another. In a heat medium circulation circuit where the intermediate heat exchanger and the use side heat exchanger are connected, temperature sensors are installed. An anti-freezing operation mode is provided in which, when the detection temperatures of the temperature sensors become equal to or lower than a set temperature Ts while a compressor or pumps are stopped, the heat medium is circulated to perform anti-freezing of the heat medium.

A refrigerating and air-conditioning apparatus performs, even during a heating operation under air conditions leading to formation of frost, a defrosting operation while simultaneously continuing a heating operation and that improves comfort through heating by ensuring an appropriate amount of ventilation. A plurality of refrigeration cycles that are capable of independently performing a heating operation and a defrosting operation, are provided. A ventilation damper of an indoor unit in which a refrigeration cycle that performs a defrosting operation is installed is closed during a defrosting operation, and a ventilation damper of an indoor unit in which a refrigeration cycle that performs a heating operation is installed is controlled to achieve a required amount of ventilation corresponding to the indoor ventilation state.

A refrigeration apparatus uses R32 as a refrigerant, and includes a compressor, a condenser, an expansion mechanism, an evaporator and an accumulator. The accumulator is disposed in the suction flow path supplying refrigerant to the compressor. The accumulator has a casing that forms an inside space to separate the refrigerant into gas refrigerant and liquid refrigerant and accumulating surplus refrigerant, an inlet pipe feeding the refrigerant that has evaporated in the evaporator into the inside space, and an outlet pipe channeling the separated gas refrigerant to the compressor. A distal end opening in the inlet pipe of the accumulator is located in a height position separated by a dimension from a bottom of the inside space. The dimension is 0 to 0.3 times a height dimension of the inside space.

An air conditioning system may include an outdoor unit including a compressor; at least one distributor connected to the outdoor unit and including a condenser and an evaporator that exchange heat between refrigerant and water; a plurality of heating pipes in communication with the condenser; a plurality of cooling pipes in communication with the evaporator; a plurality of fan coil units connected to the plurality of heating pipes or the plurality of cooling pipes; and a controller configured to perform a heating pipe search operation for matching a portion of the plurality of fan coil units with the plurality of heating pipes, and a cooling pipe search operation for matching another portion of the plurality of fan coil units with the plurality of cooling pipes, in parallel.

Operation switching units, each changing directions of a refrigerant flowing through its associated indoor unit in response to a switch from a cooling operation to a heating operation, or vice versa, are each connected with the associated indoor unit through indoor communication pipes; a gas-liquid separation unit is connected with an outdoor unit through outdoor communication pipes; and the operation switching units are connected with the gas-liquid separation unit through two intermediate communication pipes preinstalled and one intermediate communication pipe newly installed. This provides a simple and cost-effective means for upgrading a preinstalled air conditioner making a switch from cooling to heating, and vice versa, into an air conditioner that can perform a cooling operation and a heating operation in parallel with each other.