Air conditioner and method for controlling same

A method for controlling an air conditioner during a full load cooling operation or during a high load dehumidification operation, the method comprising:

• phase-changing a high-temperature and high-pressure gas-phase refrigerant compressed by a compressor of an outdoor unit into a medium-temperature and high-pressure liquid-phase refrigerant in an outdoor heat exchanger and then guiding the phase-changed refrigerant to a first expansion valve and a second expansion valve of an indoor unit;
• expanding refrigerant passing through the first expansion valve and the second expansion valve to phase-change into a low-temperature, low-pressure two-phase refrigerant, and then guiding the expanded refrigerant to a first coil and a second coil through refrigerant pipes;
• evaporating refrigerant flowing through the first coil and the second coil to phase-change into a low-temperature, low-pressure gas-phase refrigerant, and then-directing guiding the evaporated refrigerant into a first manifold and a second manifold through refrigerant pipes;
• and
• circulating the refrigerant flowing through the first manifold and the second manifold back to the compressor of the outdoor unit.

A method for controlling an air conditioner during a partial load cooling operation or a low-load dehumidification operation, the method comprising:

• phase-changing a high-temperature and high-pressure gas-phase refrigerant compressed by a compressor of an outdoor unit into a medium-temperature and high-pressure liquid-phase refrigerant in an outdoor heat exchanger, and then blocking a flow of the phase-changed refrigerant by a second expansion valve of an indoor unit while the phase-changed refrigerant flows into a first expansion valve of the indoor unit;
• guiding the phase-changed refrigerant passing from the first expansion valve to a first coil;
• guiding refrigerant flowing to the first coil to a first manifold;
• guiding refrigerant passing through the first manifold to a second manifold through a path that includes a third expansion valve on a refrigerant flow pipe;
• and
• circulating refrigerant passing through the second manifold back to the compressor of the outdoor unit.

A method for controlling an air conditioner during a partial load heating operation, the method comprising:

• passing a high-temperature and high-pressure gas-phase refrigerant compressed by a compressor of an outdoor unit through a gas pipe to flow into an indoor unit;
• blocking the high-temperature and high-pressure gas-phase refrigerant supplied to the indoor unit at a first manifold and simultaneously flowing the gas-phase refrigerant to a second manifold;
• guiding refrigerant flowing from the second manifold to a second coil;
• condensing refrigerant flowing into the second coil to phase-change into a high-temperature and high-pressure two-phase refrigerant, and then guiding the high-temperature and high-pressure two-phase refrigerant into the first manifold through a third expansion valve on a refrigerant flow pipe;
• condensing the refrigerant flowing through the first manifold to a first coil to phase-change into a high-temperature and high-pressure liquid-refrigerant;
• expanding the refrigerant flowing into the first coil in a first expansion valve to phase-change into a low-temperature and low-pressure two-phase refrigerant;
• and
• phase-changing the low-temperature and low-pressure gas-phase refrigerant in an outdoor heat exchanger of the outdoor unit and then circulating the phase-changed refrigerant back to the compressor of the outdoor unit.