14 Special Vent Ops Flashcards
pg 410
Physical exertion of crews to reach the fire floor will mean:
They may have less energy to perform firefighting functions
pg 411
Truck crews should never enter high rise empty handed. If they aren’t carrying forced entry tools or vent equipment they should have
Space Scba cylinders
Hose
Tools
Lights
pg 411
Moving large amounts of tools is generally coordinated by those assigned to
Lobby control
pg 411
Low rise elevators
serve the lower floors of the building
example: Floors 1-10
pg 411
Mid rise elevators
Only floors between low and high elevators ex, floor 1 and floor 10-20
pg 411
High-rise elevators
Serve only upper floors, ex.. Floor 1 and 20-30
pg 411
Express elevators
Ground floor to upper most floor. Ex. Floor 1 and 31 or whatever highest floor is
pg 411
Freight elevators
Serve some or all floors.
also designed to carry heavier loads than ordinary passenger elevators.
pg 411
Freight elevators should only be used when authorized by the officer in charge on the fire floor.
They can handle the additional weight of ff’s in full ppe along with extra tools and equipment, weighting more than a ton
pg 412
Dangers of using elevators in a fire
Malfunction or damage from heat could recall elevator car to the fire floor or strand the elevator between floors in the shaft.
pg 412
Stack effect
Natural vertical mvnt of air, or heat and smoke, in tall structures based on differences of air density inside and outside the buildings due to temp differences. Strong vertical column of mvnt.
pg 412
With the stack effect, the greater difference between the inside and outside temp and the greater the building height,
The greater the stack effect will be
pg 412
If it is hotter inside than outside the air flow will be inward at the bottom and outward at the top. In a reverse stack effect the outside air is:
Hotter.
airflow is down and out.
pg 413
Mushrooming, aka ceiling jets
Smoke rising until it hit barrier, then move horizontally until same. Then banks down and fills
pg 413
When smoke reaches the same temp as ambient air in the high rise, it loses its buoyancy and
Stratifies, forming layers of smoke in the building.
stratification can occur near the top floor and/or several floors down below.
pg 414
Most ppv positioned at street level are only effective up to how many floors up
22
more fans at the 22 floor or around there, or add smoke ejectors at the top most floor to be vented, or both
pg 414
Highrise vent options (3)
Vertical or top ventilation
Horizontal fire floor
Horizontal above and below fire floor
pg 415
If vertical vent may endanger fleeing occupants, what might have to be used
Horizontal vent
pg 415
Fire and smoke should be vented vertically through stairwells and other vertical shafts, taking advantage of
The stack effect
pg 415
Vertical venting in highrises can prevent
Mushrooming on upper floors and does not promote lapping, which is always a danger when horizontally venting multistory buildings below the top floor.
pg 415
One of the biggest challenges to vertical or top venting is
Getting ff and equipment to the roof
pg 415
If the roof is within reach of an aerial on a highrise, it is the preferred method for
Moving manpower and equipment to the roof for venting
pg 415
If an aerial does not reach the roof, how can it be used to gain access
Reach the farthest floor it can, enter through a fire escape or window and use stair and elevators the rest of the way to the roof
pg 415
Although highrises usually have more than one stairway, few have more than one that
Terminates at the roof.
pg 416
During a fire, a stairwell can be relatively free of smoke but congested with
Occupants, attack lines and ff.
therefore dedicating one stairway for evacuation and another for fire attack is critical.
pg 416
Elevators that service the fire floor or floors above should not be used unless
The officer in charge of the fire floor deems it safe to do so.
contradicts pg. 411. moving equipment is deemed safe by IC.
pg 417
If a bulkhead or penthouse is used to ventilate the stairwell that terminates at the roof, the door should be blocked open because
If it closes it could change the vent profile dangerously
pg 417
Ventilation in the stairwell that terminates at the top floor should be delayed until
All occupants have been evacuated or in an area of refuge.
FFs should be clear of the vent stairwell prior to venting. once it is opened the stairwell can be come untenable.