Zone Pressurization Control - Honeywell AUTOMATIC CONTROL SI Edition Engineering Manual

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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
sandwich. In Figures 7C and 7D, the smoke zone consists of more
ENGINEERING MANUAL OF AUTOMATIC CONTROL
INITIATING ALARM
PANEL PROCESSOR
ALARM
DETECTORS
REMOTE
CONTROL
PANEL 1
BUS
SMOKE DETECTOR
(NFPA SYMBOL)
SMOKE MANAGEMENT FUNDAMENTALS
OPERATOR'S
CONSOLE
FAN
FLOW
SWITCH
DAMPER
END
SWITCH
FIREFIGHTERS'
SMOKE CONTROL
STATION (FSCS)
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.
179
TO ADDITIONAL
REMOTE
CONTROL
PANELS
REMOTE
CONTROL
PANEL 2
M13026
+
SMOKE
–
ZONE
+
(B)
+
+
+
–
SMOKE
–
ZONE
–
+
+
+
(D)
+
+
+ +
SMOKE
+ –
ZONE
+ +
+
+
+
+
(E)
C5154