Stair Pressurization Fan
& Fire Detection integration
According to the National
Fire Protection Association, the process of evacuating some of today’s largest
high-rise buildings may take upwards of two hours. This is by far the
most compelling argument for effective smoke control in building
stairwells.
Pressurized staircases keep exit
routes smoke free in the event of a fire, lending precious minutes to building
occupants during an evacuation. The pressures specified to keep a stairwell
pressure positive vary by code. However, the universal goal is to
restrain smoke but still allow the opening of doors in the stairwell shaft.
In
case of fire in a high rise building, a Stair Pressurization Fan (SPF) uses
clean outside air to pressurize the air in stairwells. The pressurized air
helps people escape the fire and firefighters battle the fire. It should
be work during fire condition through FACP.
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When there's a fire, clean outside air is forced by a
Stair Pressurization Fan into a stairwell. The pressurization is used to push
back on smoke, keeping the smoke out of the escape route.
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Stairways are Fire Escape
Routes
Nowadays, stairwells have better fire ratings than the
rest of the building. In other words, so people can get out when the rest of
the building is on fire, stairways don't burn.
Stairways Full of Smoke
The stairways may not burn, but they can still fill up
with smoke. The smoke can not only make it harder to see as one is getting away
from a fire, but it can:
·
Make it harder to breathe - possibly
causing injury or death
· Close off the escape route - possibly
causing people to seek another pathway of escape
Open Doors
The problem is, as people are escaping the fire, they
have to open the door to the stairway. When the door is open, preventing the
stairway from being used by later escapees, smoke follows and billows into the
stairway.
Smoke Push Back
The idea behind the stair pressurization is
that during a fire the stairway should have more pressure than the rest of the
building. That way, when the doors open, the higher pressure in the stairwell
pushes the smoke back onto the floor, keeping the escape route clear of
smoke.
The smoke free escape route also doubles as a smoke free entrance route for the
firefighters as they combat the fire.
Turning On the SPF
Except when there's smoke, the stair pressurization fans
aren't needed, so normally they're turned off. When the fire alarm system detects smoke, they're
automatically turned on.
As firefighters battle the fire, if the fire alarm system has not
turned on the stair pressurization fans, they're turned on by the firefighters.
Escape
As people are escaping a fire, and open the doors to get
into the stairways, smoke would naturally billow from a fire floor into the
stairwell. Keeping the smoke out of the stairwell by pushing it back onto the
floor, a Stair Pressurization Fan pressurizes the air in the stairwell.
Integration
In every Fire Detection system has one devices named
Control Module / Relay Module. This Module operate through FACP loop line.
Module has Loop IN /OUT & NO COM NC. Module can be programed as NO / NC
condition. An External relay may require (Depend on Module relay capacity) for
integration. If Stair Pressurization Fan starter panel has an auxiliary circuit
for Fire Alarm then only no need to put any external relay. During external
relay operation you required one adjust power supply to energized relay coil.
