Principles Of Smoke Control Systems; System Types - Simplex 4100U Application Manual

Principles of Smoke Control Systems

System Types

Maintaining
System Integrity
Two types of smoke-control systems exist – Dedicated and Non-dedicated.
•
Dedicated Smoke Control System: Is installed in a building for the sole purpose of
controlling smoke.
•
Non-dedicated Smoke Control System: Uses parts of the building HVAC system to control
smoke.
In some cases, a building has both non-dedicated and dedicated systems. Non-dedicated systems
are used throughout the building for normal areas such as offices and manufacturing facilities.
Dedicated systems are used for special areas, such as elevator shafts, stairwells, stairtowers, and
other areas that need special smoke-handling techniques.
Smoke Control System products connect to HVAC equipment to form a system for controlling the
flow of smoke during a fire condition. Smoke-control systems are designed, installed, and
maintained so that a system remains effective and provides a "Tenable Environment" during
evacuation of the protected areas. A "Tenable Environment" as defined in NFPA 92A, is an
environment in which the quantity and location of smoke is limited or otherwise restricted to allow
for ready evacuation through the space.
A major concern with any emergency signaling system, whether burglary, fire, or smoke control,
is maintaining system integrity. This task is traditionally accomplished by electrical supervision of
wiring. However because the proper operation of the fans and dampers connected to the output
circuits may involve mechanical controls and pneumatic controls, as well as electrically-actuated
parts, end-process verification is provided. The end-process verification is provided to alert the
firefighter/operator that the fan or damper has operated in response to an automatic or manual
command issued during an emergency condition. While end-process verification confirms
operation during an emergency condition, system integrity during a non-emergency
(normal supervision) conditions is checked differently depending on whether the equipment is
non-dedicated or dedicated.
The operability of the non-dedicated smoke-control equipment is verified by the "comfort level" in
the areas that are served by the equipment. In other words, if the HVAC equipment is not
functioning properly, the building occupants are soon made aware of this and the problem can be
solved.
The operability of the dedicated smoke control equipment is verified by an automatic self-test that
is performed on a weekly basis.
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