Highrise Operations - Positive pressure???

[Aussie_Fire]

Team,
Just after a little help and advice on high rise building contruction. i have heard but i am not sure as this is not my area of expertise that there are certain safety features built into highrise buildings. Most notably stairwells. Are stairwells positive pressure? Meaning if you can get to one smoke will not impede that area and will provide a fresh air source for trapped casualties trying to escape?
I guess the design trade off would be you are potetially positively ventilating the fire so if doors are left open or the fire breaches that stair column, then you risk making things worse. I have heard that positive pressure stairwells do exist but i haven't been able to confirm this.

A follow on question is, what do you advise the public regarding fire safety education? If trapped in a building do you advise heading to a window or heading to the fire stairwell. i understand in smaller buildings, you have external fire escapes but in high rise the only option is internal stairwell.

Would appreciate any help on this one team.

Jess

 

[fdhistorian]

Team,
Just after a little help and advice on high rise building contruction. i have heard but i am not sure as this is not my area of expertise that there are certain safety features built into highrise buildings. Most notably stairwells. Are stairwells positive pressure? Meaning if you can get to one smoke will not impede that area and will provide a fresh air source for trapped casualties trying to escape?
I guess the design trade off would be you are potetially positively ventilating the fire so if doors are left open or the fire breaches that stair column, then you risk making things worse. I have heard that positive pressure stairwells do exist but i haven't been able to confirm this.

A follow on question is, what do you advise the public regarding fire safety education? If trapped in a building do you advise heading to a window or heading to the fire stairwell. i understand in smaller buildings, you have external fire escapes but in high rise the only option is internal stairwell.

Would appreciate any help on this one team.

Jess

Stairwells are required to be 'smokeproof' in new construction high rise buildings. There are multiple ways to achieve this - mechanical positive pressurization, vent shaft, or exterior balcony access. Fire doors have self closing hardware and positive latching to close and remain closed. Fire resistance rated construction protects the stairway enclosure so a breach by fire should not occur until long after evacuation has been completed. Smoke management systems pressurize the stairwells, the floor above the fire, and the floor below the fire. The fire floor itself is in exhaust mode.

Where the occupants are capable of self preservation, evacuation is preferred. Where occupants are not capable of self preservation or timely evacuation, construction, compartmentation, horizontal exiting, detection, and suppression are designed to permit 'defend in place' options.

 

[Aussie_Fire]

Stairwells are required to be 'smokeproof' in new construction high rise buildings. There are multiple ways to achieve this - mechanical positive pressurization, vent shaft, or exterior balcony access. Fire doors have self closing hardware and positive latching to close and remain closed. Fire resistance rated construction protects the stairway enclosure so a breach by fire should not occur until long after evacuation has been completed. Smoke management systems pressurize the stairwells, the floor above the fire, and the floor below the fire. The fire floor itself is in exhaust mode.

Where the occupants are capable of self preservation, evacuation is preferred. Where occupants are not capable of self preservation or timely evacuation, construction, compartmentation, horizontal exiting, detection, and suppression are designed to permit 'defend in place' options.

Thank you for your help friend. this is exactly what i was after. I really appreciate your reply and the information that you have provided.
Thank you
Jess