Measurement of Smoke Control Air Egress Velocity in Annex Rooms

Air egress velocity is the minimum airflow speed required to effectively prevent smoke from entering a smoke lobby when the door is open. It is calculated based on the “Performance certification and product inspection technical standards for pressurization dampers.” This study evaluated whether the current legal method for measuring air egress velocity is appropriate and analyzed how the number and placement of measurement points affect the accuracy of flow velocity calculations. Results revealed the inadequacy of the existing legal approach in accurately representing the air egress velocity across the entire doorway. Increasing the number of measurement points improved the accuracy, and when the number of points was fixed, vertically distributed configurations yielded more precise estimates.