Smoke leakage (S): Failure of the criterion shall have happened If your move rate in duct A throughout the check exceeds 10 m³ / (m² h), connected to twenty °C and 1013 mbar, linked to The inner surface area space on the duct inside the furnace. According to points, both https://simonulbpd.blogunteer.com/35705137/fire-rated-ductworth-fundamentals-explained