Table of Contents
Advertisement
Each of these barrier systems depends upon smoke
detection for operation and where used is an important
part of establishing and maintaining smoke control
zones.
Panel and component operation
Panel functions
This chapter provides general information on the
techniques used to evaluate the physical characteristics
of smoke movement through buildings as a basis for
designing smoke control systems. Mechanical system
components consisting primarily of fans and dampers
are determined, sized, and located by the smoke control
system designer. The smoke control system designer is
an engineer, architect, or competent person, usually on
the building owner's design team.
The VM-1 smoke control system designer should not
establish smoke zones and airflow requirements as a
part of the design unless they are competent in HVAC
system and smoke movement analysis. The VM-1
smoke control system panel functions are therefore
based upon requirements established by the smoke
control system designer.
Detection of a fire or smoke condition is the same for a
VM-1 smoke control system panel and the standard
VM-1 fire alarm panel. Outputs from the smoke control
system are focused upon two areas:
•
Removing or reducing smoke from an area or zone
•
Compartmentalizing a smoke zone
Smoke control system functions do not include the
alerting of the occupants or fire department of the event;
this is performed by the fire alarm panel.
A VM-1 smoke control system panel can be a stand-
alone panel or integrated into a VM-1 fire alarm panel.
The decision to incorporate smoke control system
functions into the VM-1 fire alarm panel should be
accepted as a part of the design process by the building
owner and local AHJ requirements. There are some
jurisdictions currently requiring a stand-alone smoke
control system under their building and fire codes.
Control system supervision and instrumentation
Every smoke control system must have a means of
ensuring it will operate if needed. The means will vary
VM-1 Smoke Management Application Guide
Chapter 1: Fire geometry and smoke movement in buildings
according to the complexity and importance of the
system. Supervision devices can include:
•
The presence of operating power downstream of all
circuit disconnects
•
End-to-end supervision of wiring, equipment, and
devices in a manner that includes provisions for
positive confirmation of activation, periodic testing,
and manual override operation
•
Positive confirmation of fan activation by means of
duct pressure, airflow, or equivalent sensors that
respond to loss of operating power, problems in the
power or control circuit wiring, airflow restrictions,
and failure of the belt, shaft coupling, or motor itself
•
Positive confirmation of damper operation by
contact, proximity, or equivalent sensors that
respond to loss of operating power or compressed
air, problems in the power control circuit, or
pneumatic lines, and failure of the damper actuator,
linkage, or damper itself
•
Other devices or means as appropriate
Energy management systems
Energy management systems, particularly those that
cycle supply, return, and exhaust fans for energy
conservation, must be overridden when they control or
may operate in conflict with the smoke control system.
Smoke control is an emergency mode of operation and
is to take priority over all energy management and other
non-emergency control modes.
Materials
Materials used for systems supplying smoke control are
to conform to NFPA 90A, Standard for the Installation of
Air-Conditioning and Ventilating Systems, and its
referenced standards.
Duct materials should be designed and selected to
convey hot smoke, withstand any additional pressure
(either positive or negative) by the supply and exhaust
fans when operating in a smoke control mode. Ducts
must maintain their structural integrity during the period
when they are designed to operate. Special high-
temperature ratings for smoke exhaust fans are not
normally necessary.
25
Advertisement
Table of Contents
