The rectangular ventilation ducts and fittings are used in industrial buildings, halls and other objects where round elements cannot be used.
They are used e.g. in garages and other places where it is required to provide a small height of the duct and a big amount of air.
They are made based on m2 calculations according to the Alnor CAM software dedicated to drawing fittings with the use of frames on the ends of PQ 20, 30 and 40.
Each element is tailored to an individual specification, being made of o zinc-coated, acid-proof or aluminium material - both insulated internally or with an external jacket.
The rectangular ventilation ducts can be made as an L-shaped semi-product to facilitate long-distance transport.