Emergency smoke control systems within buildings and underground transportation facilities use air movement and pressurization to contain and remove smoke in order to provide safe exiting for occupants. Wind can be a hindrance to the smoke control systems in several ways.

For smoke control systems that use natural ventilation for exhaust or makeup air, wind pressures may seriously disrupt the system performance by redistributing airflows and causing extra unwanted mixing of smoke in exit pathways. Such disruption can occur during relatively mild wind conditions, depending on the exposure of the building openings and the wind climate at the site. Another possible effect of wind is to carry smoke that has already been exhausted to the outdoors back into the building make up air system. Makeup air locations should be placed away from smoke exhausts, ideally on different faces of the buildings and with large vertical separation.

Although wind effects have been mentioned in several codes and guidelines, there is no detailed discussion of the extent of the potential problems, nor standard analysis techniques for design purposes. This paper discusses the design issues, provides recommendations, and presents some real-world examples that illustrate the potential issues and ways of reducing wind effects.

Units: Dual