Smoke leakage (S): The duct shall not Have got a leakage exceeding 5 m³/h for every 1 m² of inside area location. This shall be associated with the area location of the duct within the perforated plate to the top of the duct because of the inlet nozzles. ROCKWOOL ROXUL https://jaidensixmz.activablog.com/36163759/facts-about-fire-resisting-ductwork-insulation-revealed