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SCS Series Manual —
P/N 15712:L 7/18/16
Concepts of Smoke Control
Smoke Control System Types
2.4.2 Control Equipment
Fire Alarm Control Panel (FACP).
If necessary, the FACP and related equipment should work in cooperation with the smoke control sys-
tem and not counteract its operation. Normally, detection of a fire by a smoke detector will cause the activation of the smoke control system.
Since the detector is usually controlled and monitored by the FACP, some communication between the FACP and the smoke control system
may be necessary.
Firefighter's Smoke Control Station (FSCS).
The FSCS usually provides the control and annunciation to a particular smoke control sys-
tem. Most smoke control systems have an automatic mode that will function upon initial detection of a fire. However, the FSCS must pro-
vide full monitoring and manual override control capability for all smoke control systems and equipment. The FSCS should also have the
highest priority control over all smoke control systems and equipment.
2.4.3 Initiating Devices
Smoke Detectors.
The initiation of a smoke control system is usually caused by the detection of fire conditions from some form of initiating
device. These devices can include smoke detectors, heat detectors, and waterflow switches. Smoke detectors, whether photoelectric or ion-
ization type detectors, if properly installed and maintained can provide proper detection of smoke to initiate the activation of the smoke con-
trol system. However, activation of one smoke detector may not be sufficient cause to activate the smoke control system. A combination of
two detectors (both active) in a particular smoke zone may provide better evidence that the smoke control system should be activated.
Thermal type heat detectors and water flow switches may provide proper detection of a fire, but more often than not, a fire is already in full
swing by the time these devices are activated. Although activation of the smoke control system is essential by the time these devices are acti-
vated, it would be wise to ensure that the smoke control system is operational before these conditions present themselves.
Duct detectors should not be used for activation of the smoke control system because smoke can migrate away from the fire area into ducts
in other areas causing the smoke control system to pressurize and depressurize the wrong areas.
Manual Pull Station.
Manual pull stations should not be used for the activation of zoned smoke control systems. A pull station does not
give any specific indication of the fire's location. For instance, a person could activate a first floor pull station when evacuating the building
because of a fire on the third floor. A zoned smoke control system should not be activated as a result of this pull station because the smoke
control system would be pressurizing and depressurizing the wrong areas. However, a stairtower pressurization system or an elevator hoist-
way system could be activated in order to limit the movement of smoke.
2.5 Smoke Control System Types
A smoke control system must be designed to inhibit the flow of smoke into exit passageways, or other similar areas of the building. Such
systems must control the migration of smoke to maintain tenable conditions, but it should not be expected that such areas would be com-
pletely free of smoke. Smoke control systems must be engineered with the occupants and building design in mind. Additionally, the smoke
control system design should be coordinated with other life safety systems so that they complement each other.
A smoke control system, if properly installed and programmed in accordance with the documents listed in Section 1, “About This Manual”,
should provide the following controls:
•
Help maintain a tenable environment in evacuation routes during the time required to evacuate people from the area.
•
Help restrict the movement of smoke from the fire area.
•
Help provide conditions in non-smoke areas that will enable fire officials to conduct search and rescue operations and to find and
combat the fire.
•
Assist in protecting life and property.
Smoke control system types and implementations are shown in Figure 2.14. This flow chart shows that a smoke control system can be a ded-
icated or non-dedicated system. Once that commitment is made, any combination of protection schemes can be implemented. For instance,
the user can select a dedicated system which employs both shaft protection and floor protection where a compensated stairtower pressuriza-
tion system and zoned smoke control are used.