An air conditioning system that includes refrigerant systems respectively including an indoor unit connected to an outdoor unit by a refrigerant pipe, the refrigerant systems being controlled by a remote controller that is provided. The indoor unit includes a human sensor whose power supply operates simultaneously with the indoor unit. When the air conditioning system is in an on-state and detection information of the human sensor indicates absence, the indoor unit transmits an absence signal to the remote controller. The remote controller that has received the absence signal transmits an absence-off period signal including absence-off period control information set in advance to the indoor unit. The indoor unit that has received the absence-off period signal is controlled according to the absence-off period control information.