Which system in Air Distribution System takes the hot exhaust air from the IT equipment...

The return system in an air distribution system takes the hot exhaust air from the IT equipment and returns it to the Computer Room Air Conditioner (CRAC) unit. The CRAC unit cools the hot exhaust air and recirculates it back into the data center. The return system typically includes ducts, grills, and other components that allow the hot air to be efficiently and effectively returned to the CRAC unit.

Supply system is responsible for bringing in the cooled and filtered air from the CRAC unit to the data center.

Maintenance system and regulation system are not related to air distribution system in the data center.