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Section 602.01
Ventilation
I. Scope:
This standard applies to incidents involving structures and confined spaces where the prompt removal of smoke, heat and other products of combustion are necessary to quickly and safely extinguish the fire.
II. General:
A. Prompt and efficient ventilation is necessary to mitigate the potentially harmful effects of smoke, heat and other contaminants within structures and confined spaces.
B. If unchecked, smoke and heat contribute to property damage and can injure and kill those who enter.
C. Smoke and heat also hinder firefighters in their efforts to perform search and rescue operations as well as suppression.
D. Therefore, it is the policy of this department to provide prompt and proper ventilation in all buildings and confined spaces in which smoke, heat or other products of combustion are present unless otherwise ordered by the Incident Commander.
III. When To Ventilate:
A. Ventilation shall always be performed whenever:
1. Heat, smoke and other products of combustion are present.
2. Hose crews cannot effectively make an interior attack due to excessive heat and poor visibility.
3. Heat, smoke and other products of combustion block escape routes for the occupants of the structure.
B. When performing ventilation, the following safety precautions should be observed:
1. Read the smoke. Observe conditions that might indicate that the potential for flashover or backdraft is present.
2. Never direct hose streams into ventilation openings.
3. Always have charged hoselines in place prior to beginning ventilation.
4. Maintain communications.
5. Wear full protective clothing and SCBA.
6. Always consider structural soundness.
7. Exercise caution whenever using power saws, axes and other sharp instruments.
8. Watch for overhead hazards (powerlines, etc).
9. Secure a lifeline to any firefighter who is on a potentially weakened roof with the use of rescue rope and appropriate knots and lashings.
10. Remember that improper ventilation techniques may contribute to fire spread.
IV. Types of Ventilation:
A. Natural: Accomplished by making use of wind currents. Open the building on the leeward side to allow the smoke to escape and then open the windward side to provide fresh air currents.
B. Mechanical: Use of electric or gas powered fans or blowers to evacuate smoke from a building or confined space.
1. Negative Pressure: Exhaust smoke from the building.
2. Positive pressure: Blow fresh air into the building to force the smoke out.
C. Horizontal: Generally inflicts less damage to the building than vertical ventilation, since it is typically accomplished through available portals such as doors and windows.
D. Vertical: May also take advantage of natural building features such as sky-lights, shafts and roof-top stairways. Many times, the only option is to cut ventilation openings into the building itself.
E. Hydraulic: Using a hand nozzle (in full fog) through an open window from inside the building. The opening should be on the leeward side of the building.
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