The TUNE-S-AHU are rectangular, multi-blade dampers that provide effective airflow adjustment and shut-off function in air handling units and fan systems. Available in different sizes, the dampers are designed for use in indoor and conditionally in outdoor climate conditions when installed on the body of a fan, or in a rectangular duct section. The unit is equipped with a spring return electric actuator that closes in event of power failure or interruption. Manual operation and adjustment are also possible.

The units can operate in both airflow directions. The air tightness of the damper is classified as C4 according to the standard EN 1751 pressure range up to 1000 Pa. This is the maximum recommended duct pressure for this product. It has an operating temperature of between -20°C to 100°C in the duct,  and to a maximum of 50°C on the actuator. The TUNE-S-AHU flange and casing are manufactured from galvanised sheet steel. The opposed action blades are extruded aluminium profiles and are equipped with a rubber gasket, eliminating air leakage when in a closed position.