How is stairwell pressurization accomplished?
Pressurization of the exit passageway can be accomplished in a variety of ways such as the use of air transfer grille(s) in in the walls between the interior exit stairway and exit passageway, installation of ductwork connecting the two areas, or by installation of a separate fan for the exit passageway.
What is stairwell pressurization testing?
Stairwell pressurization testing ensures that a building’s occupants can exit safely during a fire emergency. Correct pressures, air change rates, and door pull forces are key ingredients in a safe structure.
Do stairwells need ventilation?
Vestibules and egress stairs are generally not considered “occupiable” spaces under ASHRAE 62, and therefore would not require ventilation. However, if you want people to actually use the stair, adding ventilation would make it a more attractive option.
Why is stairwell pressurization important?
In essence, stair pressurization creates a barrier to help control smoke movement in case of an emergency. The higher pressure in the stairwell “pushes” the smoke back into the lesser pressurized hallway, allowing the escape route to be free of smoke.
Why are staircases pressurized during emergency evacuation?
The reason is that by providing a door across the transfer passageway, it would impede the movement of occupants moving towards staircase A1. In this way, the evacuation process within the whole shaft of staircase A would be slowed down.
What is the reason to have a pressurized enclosed stairwell in an apartment high rise building?
Most building codes require the fire stairwells in a high-rise building to be pressurized to keep smoke out. The stairwell pressurization serves several purposes: • Inhibit migration of smoke to stairwells, areas of refuge, elevator shafts, or similar areas.
Is stairwell pressurization required?
As alluded to above, we most commonly see stairwell pressurization systems utilized in high-rise buildings. The code simply requires that every exit stair serving floors more than 75 feet above the lowest level of fire department access shall be a ‘smokeproof enclosure.
What is meant by stair pressurization?
A pressurization system is intended to prevent smoke leaking passed closed doors into stairs by injecting clean air into the stair enclosure such that the pressure in the stair is greater than the adjacent fire compartment.
Why do I need stairwell pressurization?
Most building codes require the fire stairwells in a high-rise building to be pressurized to keep smoke out. The stairwell pressurization serves several purposes: • Inhibit migration of smoke to stairwells, areas of refuge, elevator shafts, or similar areas.
When is stairwell pressurization required?
The requirement for pressurized enclosure of the stairway is for highrise buildings (as you said with occupied floors over 22 m the lowest level of fire department access)and for underground buildings (with occupied floors below 9 m below the finished floor of the lowest level of exit discharge).
What is a stair pressurization fan (SPF)?
A Stair Pressurization Fan (SPF) uses fresh outside air to increase the air pressure inside the stairway. The increased pressure from the fresh air pushes the building’s smoke laden air away from the escape route inside the stairwell.