On designing horizontal ceiling vent in an atrium

The design of static smoke exhaust systems for atria will be reviewed in this article. Horizontal ceiling vent is considered as there had been numerous works on vertical vents. The physical principles behind will be outlined. In most of the design guides, the vent area is derived by taking buoyancy as the driving force. This key point will be demonstrated. The effects of wind on the performance of ceiling vent will also be considered. The results should be useful for the Authority to consider accepting natural vents as an alternative to dynamic smoke exhaust systems.