Smoke leakage (S): The duct shall not Possess a leakage exceeding five m³/h for every 1 m² of inside area location. This shall be related to the area spot of your duct through the perforated plate to the top from the duct because of the inlet nozzles. The basement extract https://fire-resisting-ductwork-i77889.blazingblog.com/36968175/grease-tight-extract-ductwork-no-further-a-mystery