AT-2472 -- Experimental Studies of Mechanical Venting for Smoke Control in Tall Office Buildings

Tests have been conducted on four tall buildings to determine the rate of air extraction required to produce enough pressure difference across a fire floor enclosure to prevent smoke from spreading to other floors. Over-all and component leakage values of the floor enclosures were determined; and the effect on the required exhaust rates of various modes of operating the building air-handling systems were investigated.

A graphic method was developed for selecting the correct exhaust fan, taking into account leakage flow from floor spaces into the exhaust shaft as well as the exhaust flow from the fire floor.