Effect of wind on smoke movement and smoke control systems

Abstract

It has long been recognised that the natural wind has a major influence on air movement in buildings and that the shape and size of buildings will influence the character of wind flow. The action of wind on leaky buildings is a complex topic and, in the inclusion of information on the interaction of wind and buildings in the assessment of smoke movement and the design of smoke control systems, has required some simplification of the aerodynamic data. Such simplification and some assumptions about the ventilating effects of the natural wind, may mask conditions of failure for smoke control systems. Some possible failure modes are discussed with respect to different types of smoke control systems and it is noted that a single state may be a failure state for one type of smoke control system but enhances the effectiveness of another type of system. The alternative effects of the natural wind indicates that the designer must be fully aware of the objectives and physical concepts of each type of smoke control system.