Air Terminal Units (ATUs) are zone-level air distribution devices that regulate airflow to ensure maximum occupant comfort. These units control the temperature within specific zones, maintaining the desired temperature in occupied spaces. In ATU systems, air is supplied by a single air handling unit. The two most common accessories are hot water coils and electric coils for supplementary heating, often referred to as reheat.

Air terminal units are available in both standalone configurations and BMS-compatible applications, including BACnet, Modbus, and LonWorks.