Zone Pressurization Control - Honeywell AUTOMATIC CONTROL Engineering Manual

ALARM
DETECTORS
COMMUNICTIONS
SMOKE DETECTOR
(NFPA SYMBOL)
Fig. 6. Typical Smoke Control System Meeting the Requirements of UL Standard 864 and NFPA 92A.
The following discussions cover smoke control applications
for building zones, stairwells, and large areas including malls
and atria. Each of these discussions conclude with a typical
operational sequence complying with UL Standard 864 for the
smoke control system illustrated in Figure 6.
Products utilized in smoke control and management systems
should be ULI labeled for the following applications:
— DDC Panels: Smoke Control Equipment.
— Building Management System/Fire Control System:
Critical Process Management, Smoke Control, or Fire
Control Unit Equipment

ZONE PRESSURIZATION CONTROL

The objective of zone pressurization is to limit the movement
of smoke outside the fire or the smoke control zone by providing
higher pressure areas adjacent to the smoke zone. Zone
pressurization can be accomplished by:
— Providing supply air to adjacent zones
— Shutting off all returns or exhausts to floors other than
the fire floor
— Exhausting the smoke zone (also aids stairwell
pressurization systems by minimizing buoyancy and
expansion effects)
— Shutting off, providing supply air to, or leaving under
temperature control all supplies other than those
adjacent to the fire floor
A smoke control zone can consist of one or more floors or a
portion of a floor. Figure 7 illustrates typical arrangements of
smoke control zones. The minus sign indicates the smoke zone.
The plus signs indicate pressurized nonsmoke zones. In the
event of a fire, the doors are closed to the fire or smoke control
zone and the adjacent zones are pressurized. In the example in
Figures 7A and 7B, the floors above and below the smoke zone
are pressurized. The application in Figure 7B is called a pressure
INITIATING ALARM
PANEL PROCESSOR
OPERATOR'S
CONSOLE
REMOTE
CONTROL
PANEL 1
BUS
SMOKE MANAGEMENT FUNDAMENTALS
TO ADDITIONAL
REMOTE
CONTROL
FAN PANELS
REMOTE
FLOW
CONTROL
SWITCH
PANEL 2
DAMPER
END
SWITCH
FIREFIGHTERS'
SMOKE CONTROL
STATION (FSCS)
sandwich. In Figures 7C and 7D, the smoke zone consists of
more than one floor. In Figure 7E, the smoke zone is only a
part of a floor and all the rest of the building areas are
pressurized. Smoke zones should be kept as small as reasonable
so control response can be readily achieved and quantities of
air delivered to the nonsmoke zones can be held to manageable
levels.
+
+
+
–
+
+
+
(A)
+
+
+
+
+
+
–
–
–
+
+
+
+
+
+
(C)
+
+
+
+
+
+
Fig. 7. Typical Zone Pressurization Arrangements for
Smoke Control Zones.
The practice of exhausting air as a means of providing higher
pressure areas adjacent to the smoke zone should be examined
carefully. Exhausting air from the fire floor may tend to pull
the fire along and cause flames to spread before they can be
extinguished.
ENGINEERING MANUAL OF AUTOMATIC CONTROL
179
M13026
+
SMOKE
–
ZONE
+
(B)
+
+
+
–
SMOKE
–
ZONE
–
+
+
+
(D)
+
+
+
+
SMOKE
+
–
ZONE
+
+
+ +
+ +
(E)
C5154