Field tests of stairwell and vestibule pressurization systems were performed in a 32-story high-rise building. Pressure differences in the stairwell, and vestibule and average air velocity were tested under various conditions. Test results indicate that indirect pressurization through a stairwell is feasible. Ignoring stack effect, the worst door-opening condition is that the fire doors of the top or bottom three adjoining floors of the building are open simultaneously. Pressurization systems in combination with corridor smoke exhaust systems are advantageous in preventing the spread of smoke to the escape routes. Tests demonstrate that inappropriate stairwell and vestibule pressurization systems not only fail to ensure safe evacuation but also have serious safety issues.

Units: Dual