AUC 349 POSITIVE PRESSURE FANS Flashcards
The tendency of air is to move from an area of
Higher pressure to a lower pressure
Positive pressure fans can be used in which stairwells
Attack and Evacuation stairs
The units which carry these fans are usually dispatched on a
10-77
The attack stairway shall be announced to
All members on scene via the primary tac channel 1 and also relayed to the borough dispatcher
What is the stairway that will be given 1st consideration to be pressurized
The Attack Stairway
The Evacuation stairway will be pressurized when necessary
Who informs the IC where to place the fans
Ventilation support group supervisor
When the fans are in correct position who needs to be notified
IC, Stairwell pressurization will not be initiated until authorized by the IC
PPF’s in operation should never be
Left unattended
If negative results are happening with the fan operation we need to
- Throttle down the fan to idle
- Close the stairway door
- IC must be notified
Due to the noise created by the fans
HT headsets (Dave Clark System) shall be utilized by members operating the fans to maintain communications
The priority use of the PPF’s
1) Pressurizing the attack stairwell
2) Pressurizing the evacuation stairwell for smoke & CO control
3) Ventilating the public hallways for smoke and CO control
Pressurization of the Attack stairways is most effective when
Done simultaneously with the fire attack
The optimum placement of the fan is
4 to 6 feet back from the attack stairway door on the GROUND floor and directly facing the door at an 80 degree angle (468)
The fan shall be placed to blow
Into the stairwell
The PPF’S should not be placed
IN the stairwell. Placing the fan in the stairwell does not create any pressure in the stairwell. It may create higher CO levels and negative stack effect by pulling smoke and heat down the stairwell
The pressure delivered to the attack stairway will be great enough to have
Up to 3 stairwell doors open and pressurization to remain effective.
One fan can provide proper pressure in the stairwell up to
10 stories
2 PPF’S can pressurize a
40 story building
If the fire floor is ABOVE THE 10TH FLOOR or additional pressures are required a 2nd fan must be brought to
3 floors below the fire floor and set up
In buildings over 40 feet tall the IC should consider
Special calling an additional ventilation support group
When pressurizing the stairways the bulkhead door must
Remain closed unless there is an extreme smoke condition. We can vent these stairs by having a member BURP the bulkhead doors by opening them for approx 60 seconds at a time
Sequential ventilation is done by
- Pressurizing the evacuation stairs
- PPF’s shall be placed on exterior of building with exhaust hoses being used
- The process will begin on the ground floor or cellar and continue on each floor until the CO is reduced to acceptable levels
If CO levels are in the ___-___ range, gasoline powered PPF’S will not significantly reduce those levels due to the CO emissions produced by the fans
0-60 PPM
Do not request a Vent Support Group
Continue with natural ventilation
