Roof Fans

The VDU range of vertical discharge units are mounted at the end of an extraction system. There are several ways of terminating the discharge of a ducted application, the VDU is one of them. This preferred method of air discharge helps to ‘throw’ fumes higher into atmosphere.

The unit is positioned at the end of a vertical duct of identical dimension and bolted to the duct work via mating flanges. In many cases, the axial fan is positioned at the end of the duct run and the VDU is then bolted directly to the fan.

The unit has a butterfly type damper which remains open while the fan is in motion and closes through gravity  when the fan is switched off. The closing of the dampers prevents the rain from entering the duct.

The units are constructed from pre-galvanized steel and a hot dip galvanized flange as standard. Although the units are manufactured to suit a range of axials, the flange holes can be drilled to dimensions and PCDs to suit other manufacturer’s equipment.

The units are available in nine sizes from 315mm to 1000mm.