Trane Engineered Smoke Control System, Application Manual

Page: 21 / 156

Applications of smoke control methods
BAS-APG001-EN 9
Single and multiple injection pressurization techniques
The single injection and multiple injection techniques provide
pressurization air to a stairwell (Figure 6). Both techniques use one or
more pressurization fans located at ground level, roof level, or any
location in between.
The single injection technique supplies pressurization air to the stairwell
from one location.
IMPORTANT
The single injection technique can fail when stairwell access doors are
open near the air supply injection point. Pressurization air will escape
and the fan will fail to maintain a positive pressure difference across
access doors farther from the injection point.
The multiple injection technique supplies pressurization air to the
stairwell from more than one location. When access doors are open near
one injection point, pressurization air escapes. However, other injection
points maintain positive pressure differences across the remaining access
doors.
Figure 6: Sample single and multiple injection methods
Elevator shaft smoke control
Elevator shaft smoke control uses pressurization to prevent smoke
migration through elevator shafts to floors remote from the source of the
smoke. Elevator shaft smoke control is similar to stairwell smoke control.
The stairwell pressurization techniques described previously are
applicable to elevator shaft pressurization.
Designating an elevator as a fire exit route is an acceptable, though not
typical, practice. NFPA 101 (NFPA 2003,
Life Safety Code ) allows
elevators to be second fire exit routes from air traffic control towers. For