Occurrence of a phenomenon in which an air current that has just been blown from any indoor unit is drawn into an adjacent indoor unit is reduced. A controller makes each of a plurality of indoor units perform a partial supply operation. In the partial supply operation, the controller controls an airflow direction adjusting flap such that, regarding the indoor units adjacent to each other with a predetermined distance α interposed therebetween, air currents are blown from both outlet openings which face each other with the predetermined distance α interposed therebetween, and that the air currents collide with each other.