Smoke leakage (S): The duct shall not have a leakage exceeding 5 m³/h for every 1 m² of inner area region. This shall be relevant to the surface location of your duct from your perforated plate to the tip of your duct through the inlet nozzles. Also, this section examines https://fire-resisting-ductwork-i81122.blogdeazar.com/37217838/grease-tight-extract-ductwork-an-overview