Rectangular ventilation ducts are produced of galvanized, aluminium and acid-resistant sheet with 100x100 mm up to 2000x2000 and optionally in bigger dimensions.
They are available in low and medium-pressure versions and the version for smoke removing installations. The range includes also ducts insulated inside with mineral wool having high acoustic and thermal properties.
In case of thermal insulation it is possible to cover external surface of a duct with aluminium, galvanized or acid-resistant sheet.
In the case of great sections additional straight and cross reinforcement is made depending on a size of a duct and assumed pressure inside an installation.