Smoke leakage (S): The duct shall not Have a very leakage exceeding five m³/h for each 1 m² of interior floor location. This shall be connected with the surface area region with the duct in the perforated plate to the tip on the duct because of the inlet nozzles. ROCKWOOL https://grease-tight-extract-duct22334.humor-blog.com/35630756/5-simple-statements-about-grease-tight-extract-ductwork-explained