Elevators; Smoke Control For Elevator Shafts - Andover Controls Infinity Manual

The Fundementals of Smoke Control

Elevators

Elevator shafts present a special menace with regards to smoke control.
The elevator shafts form perfect chimneys to draw smoke into the upper
levels of a building. Since elevators usually have openings on each floor,
and the seals on the elevator doors are often poor, the elevator shaft can
become a mechanism to spread smoke throughout a building. Smoke
control in an elevator shaft is an important consideration in the overall
smoke control plan.
Figure 1-10. Smoke Control For Elevator Shafts
If you could manage to make them safe during smoke emergencies,
elevators would ease the evacuation of the building, especially for
people in wheelchairs. To have the elevators usable during a smoke
emergency, you need to pressurize the elevator shafts the same way you
pressurize a stairtower.
However, pressurizing the elevator shaft presents a number of problems.
While the elevator doors can be fitted with improved seals and rubber
sweeps, these systems will not totally eliminate air leakage. Also, most
elevator shafts are not designed to be pressurized. They often have large
openings at the top where the cables feed into the winding room. Shafts
are often constructed of porous material that cannot contain the air
pressure. And since most shafts are not designed to be inspected after the
elevators are installed, finding and repairing cracks that would let smoke
infiltrate or pressure escape is difficult.
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Low Pressure Area
Created by Elevator
Special Smoke
Proof Elevator
Doors
Low Pressure Area
Created by Elevator
Pressurization Fan
for Elevator Shaft
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