While vestibule pressurization smoke control systems are now popularly used in Japan, it cannot be said that a rational method for determining the required rates of air supply has been well established. This paper proposes a practical design method of vestibule pressurization smoke control systems. This method comprehensively covers the fire scenarios corresponding to every stage of evacuation, namely, fire room evacuation, fire floor evacuation and whole building evacuation, and the air supply rates are determined to meet all the criteria for assuring the safety at these stages. The calculation procedure consists of a set of simple formulas for pressure and opening flow rates developed based on the average pressure difference concept so can be followed only by the use of a hand calculator.
