HLU’s roof fans are designed for vertical intake and installation outside the building. They can also be installed horizontally with the appropriate accessories. They are especially suitable for use in buildings without a ventilation plant and are used in laboratories (fume hoods), schools and research facilities, among others. The exhaust air is blown vertically upwards, minimising the deposition of aggressive substances on the roof.  The internal motor is separated from the air flow and therefore does not come into contact with the aggressive conveyed medium. Rainwater that falls into the discharge opening exits at the bottom of the housing, thus preventing water from entering the piping connected to the suction opening. For use in potentially explosive areas, we can also supply the HF roof fans in an explosion-proof version for zones 2 and 1 in accordance with ATEX.