Smoke leakage (S): The duct shall not Have a very leakage exceeding 5 m³/h per 1 m² of internal area area. This shall be associated with the surface place on the duct in the perforated plate to the tip from the duct because of the inlet nozzles. These rules are https://fire-resisting-ductwork-i91223.blog2freedom.com/36930843/top-grease-tight-extract-ductwork-secrets