Decription The varible swirl diffuser OD-8 VAV is designed for the systems characterised by variations in air flow. To maintain roughly constant air velocities within the occupation zone, a regulation damper is built in the diffuser. Under low flow rates, the entire air flow is directed towards the central area. With the increasing flow rates, a part of the air flow is directed towards the peripheral diffuser section, according to the setting of weights. Two sizes are foreseen: 600/44 and 625/48. Air flow area: 200-500 m3/h.