Smoke leakage (S): The duct shall not Use a leakage exceeding five m³/h per 1 m² of interior surface place. This shall be related to the area region in the duct with the perforated plate to the tip in the duct because of the inlet nozzles. CE & UKCA marked https://fire-resisting-ductwork-i78901.actoblog.com/37688512/top-guidelines-of-grease-tight-extract-ductwork