Fire Safety Science Digital Archive

In case of occurrence of a fire in a building one of the essentials is to ensure that the occupants are able to leave the fire area to a place of safety. This entails the provision of escape routes leading either to outside the building or to designated areas within. In the case of multistorey blocks of flats, and other buildings with similar occupancy hazards, it is customary to provide corridors leading to staircases, with limitations on the maximum distance people have to travel, to reach one or other of the staircases available. In some buildings where only one staircase is provided a lobby connects it to the corridor and to ensure that the lobby stays clear of smoke one of the measures commonly adopted is to ventilate it to the outside air. For this purpose the lobbies are usually located in the external walls and provided with permanent openings in one or more walls. The provision of permanent openings has never been favoured by the occupants as it leads to draughts and rain penetration. Their effectiveness as a means of clearing smoke has also been questionable and there had been a lack of data on their likely behaviour in fires. This paper reports some full scale tests which have been performed in a building to determine the effectiveness of permanent openings in external walls as a means, of clearing smoke.