Optimization of design schemes for pressurized air supply systems in smoke-preventing staircases and independent anterooms

As a reliable way to prevent smoke, pressurized air supply can effectively prevent fire smoke from entering the smoke-proof part when a fire occurs in buildings. This paper analyses three pressurized air supply methods in the smoke-preventing staircase and independent anteroom: 1) the staircase and the independent anteroom are separately mechanically pressurized; 2) only the staircase is mechanically pressurized and supplied while the independent anteroom has only one door; 3) only the independent anteroom is mechanically pressurized and the staircase adopts openable external windows for ventilation. This paper analyses the airflow rules of the three pressurized air supply methods, and gives the calculation formulas of air volume, pressure difference, and wind speed in each flow direction. The research uses a calculation example to analyse in detail, and gives the optimization process of three design schemes. Further, results have been extended to different building floors, and conclusions are provided based on various cases.