Air conditioning system and method of controlling an air conditioning system

A method of controlling an air conditioning system, the method comprising:

• driving a compressor disposed in an outdoor device to perform a main heating simultaneous cooling operation, in which a first portion of a plurality of indoor devices perform a heating operation, and a second remaining portion of the plurality of indoor devices performs a cooling operation;
• opening an outdoor expansion device disposed in an outdoor tube to introduce a two-phase refrigerant, which is introduced into the outdoor device, into an outdoor heat exchanger;
• and
• opening a bypass valve disposed in a bypass tube to bypass at least a portion of the two-phase refrigerant to be introduced into the outdoor heat exchanger, wherein the outdoor tube and the bypass tube are branched to extend from an outdoor branch.

Apparatus for controlling an air conditioning system, the apparatus comprising:

• means for driving a compressor disposed in an outdoor device to perform a main heating simultaneous cooling operation, in which a first portion of a plurality of indoor devices perform a heating operation, and a second remaining portion of the plurality of indoor devices performs a cooling operation;
• means for opening an outdoor expansion device disposed in an outdoor tube to introduce a two-phase refrigerant, which is introduced into the outdoor device, into an outdoor heat exchanger;
• and
• means for opening a bypass valve disposed in a bypass tube to bypass at least a portion of the two-phase refrigerant to be introduced into the outdoor heat exchanger, wherein the outdoor tube and the bypass tube are branched to extend from an outdoor branch.