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Evaluating Positive Pressure Ventilation In Large Structures: School Pressure and Fire Experiments



Stephen Kerber


A series of experiments was run in a masonry educational building examining the ability of PPV fans to limit smoke spread or to remove smoke from desired areas. Preliminary experiments examined the pressure increase created by portable fans and mounted fans in different configurations and locations. The two main fire scenarios included a long hallway with classrooms and a gymnasium. Both scenarios included fires that produce a large amount of smoke and hot gases and instrumentation was placed to assess tenability criteria and how PPV tactics can either increase or decrease survivability. Measurements included temperature, pressure, thermal imaging and video views. In this limited series of experiments in the long hallways of this masonry educational building, the use of positive pressure ventilation to increase pressure to reduce temperatures, limit smoke spread and increase visibility was effective. This series of experiments demonstrates that fire service positive pressure ventilation fans can be used successfully in large structures. Success can be gauged by the increased tenability of potential victims and improved conditions for firefighting crews. The use of PPV fans in the classroom fires as well as the gymnasium fires demonstrated that both of these criteria were met successfully.
Technical Note (NIST TN) -


Positive Pressure Ventilation, PPV, Fire, fire fighting, tactics, School


Kerber, S. (2008), Evaluating Positive Pressure Ventilation In Large Structures: School Pressure and Fire Experiments, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 24, 2024)


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Created July 1, 2008, Updated February 19, 2017