Air supply system

In this air supply system, the consumption of extra energy generated by each fan is suppressed. A second unit (30) has a second fan (31) that supplies first air (SA) to a target space (100). A duct (40) transports, to the second unit (30), the first air (SA) fed from a first unit (20) by the first fan (21). A remote sensor (70), which is a first detection unit, detects information on second air (RA) in the target space (100). A main controller (51), which is a first controller, communicates with the second unit (30) and the remote sensor (70). The second unit (30) includes a second detection unit (32) that detects the amount of air blown by the second fan (31) and a sub-controller (52) that is a second controller for controlling the rotation speed of the second fan (31). The main controller (51) determines a target air volume of the second unit (30) on the basis of the information pertaining to the second air (RA) and acquired from the remote sensor (70), and instructs the target air volume to the sub controller (52). The sub controller (52) controls the rotation speed of the second fan (31) such that the amount of air detected by the second detection unit (32) becomes the target air volume.