TROX swirl diffusers of the VDW type are manually adjustable. They enable the flow direction to be adapted to changes in the building structure at any time.The swirling air discharge results in high induction of the room air, leading to a rapid reduction in air velocity and air stream temperature. The diffuser is supplied with a round or square front, according to the prevailing architectural requirements. The diffuser is connected to the air duct system via the plenum box, in either vertical or horizontal configuration. Swirl diffusers of the VDW type can be deployed for supply or exhaust air.