Hazards Due to Smoke Migration Through Elevator Shafts. Volume 1. Analysis and Discussion. Final Report.
Hazards Due to Smoke Migration Through Elevator Shafts.
Volume 1. Analysis and Discussion. Final Report.
Klote, J. H.
NIST GCR 04-864-1; 35 p. June 2004.
elevators (lifts); fire hazards; smoke; migration;
building fires; temperature; smoke flow; doors; windows;
smoke transport; people movement; tenability; weather
effects; floors; scenarios; visibility; toxic gases;
During building fires, smoke often migrates through
elevator hoistways to locations remote from the fire.
One of the reasons for concern is that a closed elevator
door has a leakage area of approximately 0.056 square
meters (0.6 square feet). This is a report of a project
to study the hazards due to smoke flow through elevator
hoistways. Smoke flow and the resulting hazard to life
are analyzed for 27 scenarios in 5 buildings ranging
from 6 to 58 stories. A fire scenario is the outline of
events and conditions that are critical to determining
the outcome of alternate situations and designs. In
addition to the fire location and heat release rate, the
fire scenario includes the status of the doors and other
building systems. Other factors addressed are outside
temperature, wind, height of elevator hoistway, height
of building, leakage paths in the building, leakage of
elevator doors, and other shafts. Stairwells are also
included. Both sprinklered and non-sprinklered fires are
included. Smoke transport throughout the buildings was
simulated by a combination of zone fire modeling and
network modeling. Options considered for mitigating
hazards due to smoke flow through hoistways include (1)
the use of enclosed elevator lobbies with automatic
closing doors, (2) temporary barriers and (3) judicious
positioning of cars within the hoistway. The results of
the calculations showed that the use of enclosed
elevator lobbies increased the time to reach hazard
criteria significantly as compared the results without
such lobbies. The use of automatic roll down barriers
tended to increase the time to reach hazard criteria to
some extent. The use of judicious positioning of
elevator cars had no effect on the time to reach hazard