Smoke leakage (S): Failure of the criterion shall have happened Should the movement rate in duct A through the check exceeds 10 m³ / (m² h), relevant to twenty °C and 1013 mbar, linked to The inner floor space of the duct In the furnace. has contacted for comment, Tass https://fire-rated-ductworth67788.blogsmine.com/37266964/fire-rated-ductworth-an-overview