Smoke Control in Atrium Buildings Using Depressurisation

Part 1 : Design Principles

Abstract

Smoky gases in an atrium can pass through leakage paths in an atrium facade to affect adjacent accommodation and its escape routes. It is possible for the designers of smoke control systems to take advantage of thermal buoyancy due to the fire to prevent such infiltration, by using a technique known as depressurisation.
This is Part 1 of a two-part paper in which equations are derived for the design of smoke control systems using either natural or powered depressurisation. The influence of wind pressures on the building is included in design formulae.
It is shown how depressurisation and 'throughflow' smoke ventilation can be combined in a hybrid system, either to keep the atrium smoke layer at a specified height, or below a specified temperature.
The limits beyond which depressurisation cannot be used are explored.