Investigation of the Effects of Make-up Air on Atrium Smoke Conditions

An atrium creates an attractive environment in luxurious buildings, shopping centers and prestigious hotels. Most atria have a large space, designed to provide a visual and special appeal. One of the main concerns in designing an atrium is related to fire safety and smoke movement thorough the atrium in the event of fire. As the atrium interconnects several floors, the smoke layer may descend to a level that endangers occupants on upper floors.Protecting people from the adverse effects of smoke in the event of fire is a major concern of building codes. There are several guidelines available regarding the design of smoke management systems in atria such as NFPA 92B and the ASHRAE/SFPE publication, Handbook of Smoke Control Engineering. In this study, in addition to running full-scale tests of atrium fires, CFD modelling has been conducted to investigate the effects of make-up air on the smoke layer height including the effects of make-up air velocity, opening arrangement and air flow direction.A reduction factor correlation is proposed based on the results of full-scale experiments to consider the impact of make-up air velocity, opening arrangement and air flow direction on the smoke layer height in an atrium equipped with mechanical smoke management system.