SOG Section 17 - Vent Flashcards
What should be considered in a ventilation profile?
Existing/potential flow-paths
Location and stage of fire
Fuel/vent limited
Wind direction
Smoke conditions: Volume, velocity, density, colour
Exposures
Rescue or Suppression
Building layout and construction
Integrated vent systems
Why should an open door be closed upon arrival at an incident?
Control heat-release rate and until a tactical advantage is deemed
What are the three ventilation mechanics?
Natural, Mechanical, hydraulic
What should be communicated to the venting crews during ventilation?
Changes to vent profile or conditions
What should be considered when deciding type of ventilation?
Location of interior crews
Tactics that complement IAP
Occupant whereabouts
How it will affect tactics, fire behaviour and operational time frames
What is a sector officer responsible for when using PPV to clear a house?
Coordinating opening and closing of areas for smoke exhausting
During which operation should PPV be considered shut down?
Overhaul/checking for extension
What should be considered prior to PPA?
360 completed
Flowpath determined
Confirm VEIS is complete and personnel and occupants are protected
Fire location is determined
Fire does not involve the structure
Minimum 2 crews onscene
Exhaust locations have been determined
Where should fans be placed for PPA?
Unburned side of building, 2m back from opening
How long should PPA be used?
Brief durations, not long term operations
Where should other personnel be when PPA begins?
Outside of building
What three things are to be considered DURING PPA?
Improving - Keep using
No change - reevaluate and reposition if necessary
Worsening - discontinue immediately
What else is required for PPA application?
Charged hoseline
Which direction is ideal flowpath for PPA?
Upwind, rather than downwind
What is the preferred tactical consideration along with PPA?
Transitional attack
What timeframe should be given during PPA, prior to crews entering?
30-60 seconds
Where shall the exhaust for PPA be located?
In the fire area
What size ratio should the exhaust be for PPA?
At least 1:1 to the entry, ideally 2:1
What will provide information on the effectiveness of PPA?
Exhaust outlet and backflow.
When using fans for exposure protection, where should they be located?
Ahead of moving fire to force it back into fire area
What is needed in most cases when using PPV to protect exposures?
An Exit point in the fire area
When are fans most effective for exposure protection?
Common Attic spaces
What is the “Blow-torch” effect?
Normal and predictable occurrence at positive pressure exhaust point
What should not be done during PPA to the exhaust point?
Hosestream into exhaust point
What type of structures is PPA NOT ideal for?
Larger, open, high ceiling structures
What is the distance between fans for set-up during high-rise ventilation?
1.5-2 metres between
What is the stack effect?
Air movement in and out of buildings, chimneys, etc, due to air buoyancy
What affects air buoyancy?
Air density differences due to moisture and temperature
What can the stack effect control, both negatively and positively?
natural ventilation, air infiltration and fire
Which apparatus is in charge, unless otherwise assigned, of setting up high-rise ventilation?
Third arriving
Where should venting ops be set-up for high-rises?
Exterior exit of Operations Stairwell
Who designates the Operations Stairwell, if not already determined?
Vent Sector Officer
What are the vent crew’s duties after initial set-up of ventilation at a high-rise?
2 crew members head up Operations Stairwell, other 2 members head to Evacuation Stairwell and set-up identical ventilation (2 fans in series)
What are the different options for smoke removal in high-rises?
Area of origin (door or window)
Straight across or Nearby Area of origin
Roof access
Smoke Shafts
What additional considerations should be made for determining best vent option in high-rises?
Natural wind
Stack-effect
