Post on 13-Jan-2016
VENTILATION
State of GeorgiaBASIC FIRE FIGHTER TRAINING COURSE
Ventilation
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VENTILATION
The planned and systematic release and removal of heated air, smoke, and toxic gases from a confined area and the replacement of these products of combustion with a supply of cooler, fresh air.
Ventilation
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PROPER VENTILATIONAdvantages
Simplifies rescue Reduces flashover
hazards Reduces backdraft
hazards Reduces
mushrooming
Speeds extinguishment
Salvage operations Reduces damage Decreases danger Easier firefighting Confines the fire
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VENTILATION EFFECTS
PROPER Improved visibility Lower temperatures Safer working
conditions
IMPROPER Fire may Spread Potential Backdraft May delay rescue Potentially harmful to
occupants
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TYPES OF VENTILATIONNatural
Vertical Horizontal
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TYPES OF VENTILATIONForced
HydraulicMechanical
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TYPES OF FORCED VENTILATON
Mechanical• Depressurization
• Pressurization
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MECHANICAL VENTILATIONDepressurization
Advantages• effective when others are
not
• ensures positive control
• supplements other methods of ventilation
• may be faster than natural ventilation
• good public relations
Disadvantages• May cause fire to intensify
and spread
• Needs a power source
• Special equipment is required
• Interferes with egress and ingress
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MECHANICAL VENTILATIONPressurization
Disadvantages• Needs a power source
• Special equipment is required
• May cause fire to intensify and spread
Advantages• done without
entering structure
• doesn’t interfere with ingress or egress
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HYDRAULIC VENTILATION
Advantages• requires no special
equipment
• can be performed by the same firefighter
• removes smoke faster than mechanical ventilation
Disadvantages• increase in water
damage
• increases demand on water supply
• freezing of water
• time in is limited
• firefighters may remain in structure
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VENTILATIONConsiderations
Life safety conditions
Building conditions
Fire conditions
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BACKDRAFTEffects
Structural damage
Serious injury
Flying debris
Additional heat or fire damage
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BACKDRAFTPrevention
Control openings
Open slowly
Natural vertical ventilation
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ROOF TYPES
Flat
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ROOF TYPES
Pitched or Gable
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ROOF TYPES
Arched
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VERTICAL VENTILATION Safety Precautions
Wear full protective equipment Determine the safety of the building and roof
• IF UNSAFE … STAY OFF !!! Have a charged hose line ready and in position Coordinate ventilation with other crews Observe wind direction in relation to exposures
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Note the existence of and avoid obstructions or excessive weight on the roof
Extend ladder 3 to 5 rungs above the roof line
Sound the roof for structural integrity before stepping on to it
Provide two means of escape Use life lines, roof ladders or other means to
prevent slipping or falling
VERTICAL VENTILATION Safety Precautions
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Work in groups of two but no more than necessary
Use caution around electrical wires Use tools with caution and beware of others Start power tools on the ground; and shut
off before hoisting Avoid cutting main structural supports
VERTICAL VENTILATION Safety Precautions
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The angle of cut should be away from the body
Guard the opening in the roof
Evacuate the roof when ventilation is complete
Use support members of the structure for travel
VERTICAL VENTILATION Safety Precautions
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Wear full protective equipment Determine the safety of the building Work in groups Provide two means of escape Have a charged hose line ready and in
position to protect exposures Coordinate ventilation with other crews Use caution around electrical wires Use tools with caution.
HORIZONTAL VENTILATION Safety Precautions
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VENTILATION TOOLS
Pike pole
Pick-head axe
Power Saw
Ladders
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NATURAL VERTICAL VENTILATIONProcedure
Determine where to ventilate Ladder 5 rungs above the roofline Deploy roof ladder Locate roof supports Make the opening at least 4’ X 4’ Remove roof materials Cut decking alongside joist Pry up boards Open ceiling below
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NATURAL HORIZONTAL VENTILATION
Procedure
Determine where air is to be channeled Determine where to ventilate Open structure on windward side as low
as possible Open structure on leeward side as high
as possible.
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NATURAL TRENCH VENTILATION
Follow same safety precautions as for vertical ventilation
Determine where the opening is to be made• Ahead of the fire
Cut trench from one exterior wall to the other• 4 feet wide
Use same procedures as for vertical ventilation
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DEPRESSURIZATION VENTILATION
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PRESSURIZED VENTILATION
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HYDRAULIC VENTILATION