An air conditioning system configured to supply a plurality of places in a building with conditioned air with use of ducts inhibits malfunction of the air conditioning system due to airflow volume through a utilization heat exchanger. A heat exchanger unit includes a utilization heat exchanger. The heat exchanger unit is connected with a plurality of ducts. A plurality of fan units sucks conditioned air from the heat exchanger unit through the plurality of ducts and supplies a plurality of blow-out ports with the conditioned air. The fan units include fan motors as a plurality of actuators configured to individually change supply air volume of the conditioned air. A main controller controls the plurality of fan motors such that airflow volume through the utilization heat exchanger satisfies a predetermined condition.