This air-conditioning system includes an air conditioner: a room temperature sensor; an air-conditioning room temperature sensor; and a system controller. In the system controller, a room target temperature obtainer obtains a plurality of room target temperatures. Moreover, a ventilation airflow determiner determines the ventilation airflow of each of the delivery fans on the basis of the room target temperature, the temperature in the corresponding room, and the temperature in the air-conditioning room, and a fan airflow controller controls the ventilation airflow of each of the delivery fans according to the ventilation airflow determined by the ventilation airflow determiner.