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Full-Scale Evaluation of Positive Pressure Ventilation In a Fire Fighter Training Building.

pdf icon Full-Scale Evaluation of Positive Pressure Ventilation In a Fire Fighter Training Building. (2296 K)
Kerber, S.; Walton, W. D.

NISTIR 7342; 91 p. July 2006.


fire fighters; fire fighting training; ventilation; evaluation; experiments; scenarios; uncertainty; tests; room fires; temperature; oxygen concentration; fuel load


A series of full-scale experiments was conducted in a three-story fire fighter training burn building to compare natural ventilation with positive pressure ventilation (PPV). A wood pallet and dry hay fire was allowed to burn in the structure with all doors and windows closed until the fire reached an oxygen-limited state. A door and window were then opened. The structure was ventilated naturally or with a positive pressure fan placed at the front door. Fourteen different configurations of fire room and vent locations were examined, each with both natural and positive pressure ventilation. Gas temperatures, air velocities, fire room oxygen concentrations and differential pressures were recorded and compared for the different configurations and ventilation techniques. The data indicate that, with both natural and positive pressure ventilation techniques, using correct ventilation scenarios resulted in lower temperatures within the structure at the 0.61 m (2 ft) height, where victims may have been located, and at the 1.22 m (4 ft) height, where fire fighters may have been operating. There were only limited ventilation configurations where the temperatures in rooms other than the fire room exceeded the victim or fire fighter threshold temperatures with either ventilation technique. The use of positive pressure ventilation resulted in visibility improving more rapidly and, in many cases, cooled rooms surrounding the fire room. However, the use of positive pressure ventilation also caused the fire to grow more quickly, and in some cases, created higher temperatures at the lower elevations within the structure. Overall, this limited series of experiments suggests that PPV can assist in making the environment in the structure more conducive for firefighting operations.