PURPOSE: To establish an air conditioning system control for performing an individual optimum operation control for zone by a method wherein an operating information input from a remote controller is transmitted to an air conditioner and a damper unit at a high speed.

CONSTITUTION: All the remote controllers 102 and damper units 107 are connected with communication devices 7 and 8 of an air conditioner through buses by a two-core signal line. One damper unit corresponds to one remote controller and an individual air conditioning control is carried out and at the same time a request check signal 4 for use in monitoring an inputting of operating information of the remote controller is always transmitted from the air conditioner. The remote controller transmits a request presence signal 5 in respect to a key inputting. This request presence signal 5 is received at the air conditioner and then an interruption priority communication is carried out with the remote controller having the key input. The damper is controlled in a speedy manner in response to this information of communication and the optimum zone air conditioning can be controlled, resulting in providing a communication system setting a major point on its controlling characteristics.