External Louvre Shutters Type ALS
ALS units are not fitted with backdraft shutters but otherwise are identical to the ALD series. They are generally used for supply-air applications.
Construction is extruded aluminium with a natural anodised finish and rigidly-fixed horizontal blades.
A galvanised mesh is fitted to prevent the entry of birds or vermin.
The backdraft shutters fitted to ALD units are of a fabric material and therefore rattle-free. When the fan is turned off the shutters seal quietly against the bird screen.
Louvre blades are designed to reduce the possibility of rainwater entry.
Units up to 1200mm square are supplied as a single unit, above these dimensions the units are generally supplied in modules.