1. CVFD Training – Ventilation Practices
SFFMA Training Objectives: –

2. Life Safety Reasons for Fireground Ventilation
Increases firefighter safety by reducing interior temperature, increasing visibility
Reduces chance of firefighters receiving steam burns when water applied
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Firefighter I

3. Life Safety Reasons for Fireground Ventilation
Reduces likelihood of sudden, hazardous changes in fire behavior
Simplifies, expedites search and rescue operations by removing smoke, gases that endanger trapped/unconscious occupants
Firefighter I

4. Fire Attack and Extinguishment Reasons for Fireground Ventilation
Permits firefighters to more rapidly locate fire, proceed with extinguishment
When ventilation opening made in upper portion of building, chimney effect occurs
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Firefighter I

5. Fire Attack and Extinguishment Reasons for Fireground Ventilation
Firefighter I

6. Fire Spread Control Reasons for Fireground Ventilation
Effective ventilation
Reduces rate of smoke layer development
Can reverse process of smoke layer development
Reduces rate at which fire will spread over area
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Firefighter I

7. Fire Spread Control Reasons for Fireground Ventilation
Even with proper ventilation, if fire not extinguished soon after ventilation completed, increased supply of fresh air will feed fire
Ventilation should occur only after hoseline crews ready to move in, attack
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Firefighter I

8. Fire Spread Control Reasons for Fireground Ventilation
Firefighter I

9. Reduction of Flashover Potential Reasons for Fireground Ventilation
Transition between growth, fully developed
As unventilated interior fire burns and flames, smoke, and gases extend, heat radiates back down until combustibles heated to ignition temperatures
Once ignition temperatures reached, contents will ignite
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Firefighter I

10. Reduction of Flashover Potential Reasons for Fireground Ventilation
Ventilation helps prevent flashover from occurring
Opening single door or window may not remove enough smoke, heat to prevent flashover
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Firefighter I

11. Reduction of Flashover Potential Reasons for Fireground Ventilation
If fire producing significant amount of smoke and heat but limited by available oxygen, ventilating room may cause rapid ignition of hot fire gases in upper layer, initiating flashover
Firefighter I

12. Reduction of Backdraft Potential Reasons for Fireground Ventilation
When fire confined in compartment and does not break window or burn through to outside, will reduce oxygen level until flaming combustion no longer possible
If air supply introduced, backdraft occurs
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Firefighter I

13. Reduction of Backdraft Potential Reasons for Fireground Ventilation
To prevent backdraft conditions, carefully controlled ventilation must be provided
Vertical ventilation often safest for this
Signs of potential backdraft
Firefighter I

14. DISCUSSION QUESTION
Do you know of any examples of fires in which backdraft occurred?
Firefighter I

15. Property Conservation Reasons for Fireground Ventilation
Rapid extinguishment reduces water, heat, smoke damage
Timely, effective ventilation helps extinguish interior fires faster
Smoke may be removed from buildings by natural or mechanical means
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Firefighter I

16. Property Conservation Reasons for Fireground Ventilation
When smoke, gases, heat removed from burning building, fire can be confined
If sufficient personnel, effective salvage operations can be initiated outside immediate fire area during fire control operations
Firefighter I

17. Considerations Affecting Ventilation
Is there need at this time?
Where is ventilation needed?
What type should be used?
Do fire, structural conditions allow for safe roof operations?
Are Vent Group personnel trained, equipped to ventilate building?
Firefighter I

18. Life Safety Hazards
First consideration is safety of firefighters and building occupants
Life hazards in burning building generally lower if occupants awake
If occupants asleep, a number of possibilities must be considered
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Firefighter I

19. DISCUSSION QUESTION
What are some ways to determine if there are occupants still inside the building?
Firefighter I

20. Life Safety Hazards
Depending on fire conditions, ventilation may be needed before search and rescue begins
Hazards from accumulation of smoke, gases in building
Firefighter I

21. Visible Smoke Conditions
Smoke accompanies most ordinary forms of combustion
Density of smoke increases with amount of suspended particles
Smoke conditions vary according to how burning has progressed
Firefighter I

22. The Building Involved
In addition to location of fire within building, building’s age, type, design must be considered
Other factors include number and size of wall openings, type of roof construction, etc.
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Firefighter I

23. The Building Involved
If results of preincident planning have been documented and are available to officers on fireground, may provide valuable information affecting ventilation
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Firefighter I

24. The Building Involved High-rise buildings have extra considerations
Firefighter I

25. Basements and Windowless Buildings
Without effective ventilation, access into basement is difficult because firefighters must descend through worst heat, smoke to get to seat
Several features impede attempts at natural ventilation
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Firefighter I

26. Basements and Windowless Buildings
Many buildings have windowless wall areas
In some cases, creating openings needed may delay operation considerably
Ventilating considerations
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Firefighter I

27. Basements and Windowless Buildings
Firefighter I

28. Location and Extent of Fire
First-arriving units must determine size, extent of fire as well as location
Severity, extent of fire depend on number of factors
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Firefighter I

29. Location and Extent of Fire
Phase to which fire has progressed is a primary consideration in selecting ventilation procedures
Ways that vertical fire extension occurs
Firefighter I

30. Selecting Place to Ventilate
Ideal situation one with as much information as possible about fire, building, occupancy
Many factors have bearing on where to ventilate
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Firefighter I

31. Selecting Place to Ventilate
Many considerations before ventilating building
Firefighter I

32. Horizontal Ventilation
Venting of heat, smoke, and gases through horizontal openings
Certain structures lend themselves to this application
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Firefighter I

33. Horizontal Ventilation
Many aspects of vertical ventilation apply to horizontal ventilation; different procedure must be followed
Besides direct flame contact, horizontal extension can occur in several ways
Firefighter I

34. Horizontal Ventilation Considerations — Weather
Must always be considered
Wind has most potential influence; can aid or hinder horizontal ventilation
Wind direction
Setting up natural horizontal ventilation
Firefighter I

35. DISCUSSION QUESTION
What are some other weather conditions that should be considered before performing horizontal ventilation?
Firefighter I

36. Horizontal Ventilation Considerations — Exposures
Internal — Include building occupants, any uninvolved rooms/portions of building
External
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Firefighter I

37. Horizontal Ventilation Considerations — Exposures
Because horizontal ventilation does not release heat and smoke directly above fire
Routing necessary
Routes may be same needed for evacuation
Effects on rescue, exit must be considered
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Firefighter I

38. Horizontal Ventilation Considerations — Exposures
Because heat, smoke, fire can be discharged below highest point of building
Also danger that rising gases will ignite portions of building above exit point
Rising gases may be drawn into windows/ attic vents above exit point
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Firefighter I

39. Horizontal Ventilation Considerations — Exposures
Because heat, smoke, fire can be discharged below highest point of building (cont.)
They may ignite eaves of building/adjacent structures
Unless for rescue, building should NOT be ventilated until charged hoselines in place at entry point
Charged hoselines should be ready at intermediate point where fire might spread
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Firefighter I

40. Daylight Basement Ventilation Considerations
Daylight basements
Occur in homes built on slopes
Finished basements with large exterior windows, possibly exterior door(s)
Easier to ventilate than conventional
Opening door, breaking windows, etc. provides adequate ventilation
Firefighter I

41. Precautions Against Upsetting Horizontal Ventilation
Opening a door/window on windward side of building prior to ventilation exit opening on leeward size may pressurize building, intensify fire, cause fire spread
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Firefighter I

42. Precautions Against Upsetting Horizontal Ventilation
Take advantage of air currents
If established currents blocked, positive effects may be reduced/eliminated
Firefighter I

43. Advantages of Forced Ventilation
Supplements, enhances natural ventilation
Ensures more control of air flow
Speeds removal of contaminants
Reduces smoke damage
Promotes good public relations
Firefighter I