Abstract
The basic properties of intermediate open doors necessary for predicting pressure differences between rooms in a smoke control plan were determined. These were determined in the following manner. (1) An experimental system was proposed for determining the flow rate coefficient relative to the opening angle of an intermediate open door. (2) The relationship of door closing force, door shape and pressure difference between rooms with respect to the opening angle of a free-swinging door was proposed by introducing a pressure difference distribution coefficient. (3) The relationship between the opening angle of an arbitrary free-swinging door and the average pressure difference between rooms can be estimated from the door width and height by determining this relationship for a specific door. (4) The pressure difference between rooms immediately before opening a door can be estimated from the door surface area on which pressure is acting and the door closing force regardless of the magnitude of the door closing force.
