Honeywell NOTIFIER SCS Series Operation And Installation Manual page 13

Introduction
Smoke Barrier. A vertical or horizontal membrane, such as a wall, floor, or ceiling assembly, that is designed and constructed to resist the
movement of smoke. A smoke barrier may or may not have a fire resistance rating. Smoke barriers may have openings protected by closing
devices or adequate air flows. Smoke barriers define all the boundaries of smoke control zones including walls, floors and ceilings that must
be constructed as continuous structures to limit the spread of smoke.
Smoke Control Mode. A predefined operational configuration of a system or device for the purpose of smoke control.
Smoke Control System. An engineered system that uses mechanical fans to produce airflows and pressure differences across smoke barriers
to limit and direct smoke movement. A smoke control system uses fans to move air and produce pressure variances between smoke barriers
which reduce smoke and direct its movement. A smoke control system consists of control equipment, intermediate equipment such as motor
controllers and electro-pneumatic valves, and the controlled fans and dampers. Smoke Control Systems include shaft protection and floor
protection systems. Shaft protection includes stairtower pressurization systems and elevator hoistway systems. The individual system or
combination of systems utilized depends on local codes and specific building applications.
Smoke Control Zone. A space within a building enclosed by smoke barriers, including the top and bottom, that is part of a zoned smoke
control system. Smoke Control Zones are intended to reduce smoke infiltration into non-fire areas. This is accomplished by using partitions,
floors and doors to create separate compartments which can be isolated from one another during a fire. The compartments can be entire
floors or sections within a floor. Fans are utilized to create pressure differences between smoke control zones, thus limiting the spread of
smoke from the original fire area.
Smoke Damper. A device designed to resist the passage of air or smoke that meets the requirements of UL 555S Standard for Smoke Damp-
ers. A combination fire and smoke damper should meet the requirements of UL 555 Standard for Fire Dampers, UL 555C Standard for Ceil-
ing Dampers, and UL 555S Standard for Smoke Dampers. Units for use in Canada should meet the requirements of ULC/ORD-C100-92
Smoke Control System Equipment. Smoke dampers are required in ducts at points where the ducts enter or leave a smoke control zone,
unless a duct is part of the smoke control system. Smoke dampers must restrict smoke or air movement out of or into a specific area.
Smoke Exhaust System. A mechanical or gravity system intended to move smoke from the smoke zone to the exterior of the building. It can
include smoke removal, purging, and venting systems, as well as the function of exhaust fans utilized to reduce the pressure in a smoke zone.
Maintenance of a tenable environment in the smoke zone is not within the capability of these systems. A fire floor exhaust increases the pres-
sure difference across the stairtower doors in addition to reducing the pressure on the fire floor.
Smoke Proof Enclosure. A continuous stairway which is enclosed from top to bottom by a two-hour fire wall and exits to a public area.
Entry into the stairway must be through vestibules or outside balconies on each floor. The design must limit smoke entry and include natural
or mechanical ventilation.
Smoke Zone. The smoke control zone in which the fire is located.
Stack Effect. The vertical airflow within a building caused by temperature differences between the interior and exterior of the building.
Stairtower Pressurization Systems. A system that maintains a smoke-free environment in the stairtower during a fire, for evacuation of
building occupants and as a route for firefighters. It should limit smoke infiltration from the fire floor.
Tenable Environment. An environment in which the quantity and location of smoke is limited or restricted to allow for evacuation. A tena-
ble environment is one in which life can be sustained. In a zoned smoke control system, pressure differences are used to maintain a tenable
environment in an area intended to protect building personnel during evacuation. Criteria for this concept have not yet been developed and
are not yet widely accepted.
Trouble Delay Timer. FSCS software timer that defines a time period for equipment to respond to an event; if the defined state is not con-
firmed within this time, a trouble condition occurs.
Vestibule. A small entrance hall or room, either to a building or to a room within a building.
Zoned Smoke Control. A smoke control system that includes exhaust for the smoke zone and pressurization for all contiguous smoke con-
trol zones. The remaining smoke control zones in the building may be pressurized as well. An automatic smoke detection system may be
used to automatically activate a zoned smoke control system. A smoke detection system with limited coverage (spacing greater than 900
square feet per detector) may be used if the detectors are placed where they can detect smoke before it leaves their detection area. Otherwise,
the correct smoke zone may not be annunciated and the appropriate fans and dampers may not respond. Detector location must be carefully
considered to prevent actuation of a detector outside the zone where the fire started, since air movement and pressurization of incorrect zones
could result and create an even greater hazard. A zoned smoke control system may be activated by a waterflow switch or heat detector if the
devices and their pipes or wiring are part of the smoke control zone.
NOTE: Some of the definitions in this section are reprinted with permission from NFPA 92A, Smoke Control Systems, Copyright © 1993,
National Fire Protection Association, Quincy, MA 2269. This reprinted material is not the complete and official position of the National Fire
Protection Association on the referenced subject which is represented only by the standard in its entirety.
SCS Series Manual — P/N 15712:L 7/18/16
Concepts of Smoke Control
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