Development of a Pressure Relief Window System and Its Overpressure Control Performance in Pressurized Stairwell Vestibules through Reduced-Scale Model Tests

In the event of a fire, the vestibule of a special pressurized evacuation stairwell serves as a critical space for preventing smoke infiltration and ensuring evacuation safety. However, excessive positive pressure significantly impedes the opening of fire doors, thereby obstructing evacuation. Conventional pressure control methods, such as combination dampers, flap dampers, and inverter systems, exhibiting limitations, including performance degradation, noise generation, complicated installation, and high maintenance costs. This study proposes a pressure-relief window (PRW) system that utilizes an existing window assembly within the vestibule. The proposed system enables simple and cost-effective installation within the vestibule window and automatically opens the window to relieve overpressure when excessive pressure is detected by the sensor. Experiments were conducted using the full-scale vestibule model employed for the Korea Fire Institute (KFI) flap damper performance certification tests. The damper leakage rate, based on duct static pressure, was selected as the primary variable to evaluate vestibule pressure stabilization characteristics, and comparative tests were performed against a conventional flap damper system. In addition, reduced-scale model experiments were conducted to verify the practical applicability of the proposed PRW system.