An air-conditioning system includes a plurality of indoor units; a relay unit including an intermediate heat exchanger configured to exchange heat between refrigerant and a heat medium; and a heat source unit configured to supply cooling energy or heating energy to each of the plurality of indoor units via the relay unit. The heat source unit and the relay unit are connected by a heat-source connection pipe through which the refrigerant flows, and the relay unit and the plurality of indoor units are connected by a load connection pipe through which the heat medium flows. The load connection pipe comprises a main pipe connecting between the relay unit and one of the indoor units provided at an end of the load connection pipe opposite to the relay unit. The main pipe has branch parts associated with the indoor units.