In an air conditioning system, a return compartment which is adjacent to a plurality of rooms 13, 14, 15 is formed in a building 1, the respective rooms 13, 14, 15 are provided with air intake sections 18a, 18b, 18c, 18d which spout air sent from a blowing section 40a, 40b, 40c 40d having a DC motor, an exhaust section 52 which forms exhausting current directed from the respective rooms 13, 14, 15 toward the return compartment is provided between the respective rooms 13, 14, 15 and the return compartment, the plurality of blowing sections 40a, 40b, 40c 40d and at least one air conditioning section 30a are placed in the return compartment, a total blast volume of the plurality of blowing sections 40a, 40b, 40c 40d is greater than a conditioned air volume of the air conditioning section 30a, and a blast volume of the blowing section 40a, 40b, 40c 40d is adjusted by an air conditioning load of the room 13, 14, 15. According to this, it is possible to provide the air conditioning system 29 having a relatively simple configuration, capable of changing temperature in the respective rooms 13, 14, 15 and coping with load variation caused by solar radiation if necessary, while comfortably and uniformly keeping temperature of the entire house with saved energy.