the main function of a duct ventilation system in a building is
to allow the movement of air around that building via those ducts,
where there is fire however these ducts could provide a means for
the fast spread of fire and smoke. Some buildings may already have
fire resistant duct systems installed, but for those which don’t
dampers may need to be retrospectively installed at each fire boundary.
Such a system can be activated / operated by the use of mechanical,
electrical and intumescent components. Intumescent materials however
have some very important advantages.
Intumescent Material Reacts to Heat and the Absence of Moving Parts.
When fire takes hold in building the extreme conditions, high temperatures,
different pressures and other destructive forces could cause distortion
and jamming of mechanical parts. Where Fire Rated steel mechanical
dampers are used to close blades, or in Fire and Smoke Rated dampers
where an electrical system is linked to the smoke detectors and
fire alarms are used to close blades in the ventilation system there
is a reliance on moving parts and components to ultimately stop
the spread of smoke and flames. This carries a risk of failure of
one or more of those parts. The very nature of intumescent material
however is to react to heat by expanding. The material itself will
always react the same way. Therefore the use of Intumescent materials
in fire and smoke dampers for ventilation systems adds a failsafe
element when incorporated in mechanicals and electrical systems,
or when used on their own.
Maintenance. Access to dampers in ventilation systems in some modern
buildings can be difficult and therefore inspection and proper maintenance
routines could be challenged. Also the mechanical and / or electrical
elements of those systems may naturally require maintenance. Intumescent
dampers however require minimum maintenance e.g. perhaps some cleaning
in extremely dirty conditions.
Scope In Installation Tolerances. Even if the Intumescent dampers
are distorted (within reason) during installation they should still
react to a degree where they are reliable.
and Compact. Intumescent material sections are generally light,
compact and slim and this can make them relatively easy to install
Effective. The kinds of Fire and Smoke Rated dampers which use intumescent
materials tend to be cost effective because they only need low voltage
and low levels of power to operate.
Using Duct Fire Sleeves
the fire rating of a wall or floor that has ventilation ducting
passing through it can be easily achieved by adding intumescent
duct sleeves. They don’t require mastic or screws, they’re
available in rectangular and circular form, and they also work well
as an acoustic barrier.