Presents results of a study of the pressure drop in a scale model of a stairshaft with closed treads. A 1:10 scale model (4m by 0.3m by 0.6m [13.1ft by 0/984ft by 1.96ft ) of a 10-storey stairshaft was built to study air flow resistance within the shaft under isothermal conditions, including the effect of occupant density. Three cases were investigated 1) a stairshaft with no occupant, 2) a shaft with medium density, and 3) a shaft with high density occupancy. In addition, the effects of the distributions of occupants in the stairshaft were studied. The pressure drop through the model stairshaft was measured at each storey for a range of volume flow rates between 0.0368 and 0.0901 m3/s (1.29 and 3.18ft3/s) introduced at a single injection point at the top of the stairshaft.

KEYWORDS: year 1996, calculating, pressure drop, stairwells, comparing, models, experiment, occupancy, air flow, air flow rate