1. TS 10–1
VENTILATION
The systematic removal of heated air, smoke, and gases from a structure and replacement with cooler, cleaner air

2. TYPES OF VENTILATION Vertical Horizontal Trench (strip) Basement
TS 10–2
TYPES OF VENTILATION
Vertical
Trench (strip)
Basement
Horizontal
Natural
Forced
Mechanical positive-pressure
Mechanical negative-pressure
Hydraulic

3. WHY VENTILATE? Aids in saving lives Aids in suppressing fire
TS 10–3
WHY VENTILATE?
Aids in saving lives
Aids in suppressing fire
Aids in reducing property damage

4. TODAY’S INCREASING NEED FOR VENTILATION
TS 10–4
TODAY’S INCREASING NEED FOR VENTILATION
Increased fuel load in all occupancies due to increased use of plastics and other synthetic materials
More products of combustion
More dangerous products of combustion
“Tighter” homes making heat retention greater
Increased insulation
Energy-saving glass
Vapor barriers

5. ADVANTAGES OF VENTILATION TO RESCUE OPERATIONS
TS 10–5
ADVANTAGES OF VENTILATION TO RESCUE OPERATIONS
Improves visibility
Allows for faster location of unconscious victims
Simplifies and expedites rescue
Makes conditions safer for firefighter and victims

6. ADVANTAGES OF VENTILATION TO FIRE ATTACK & EXTINGUISHMENT
TS 10–6
ADVANTAGES OF VENTILATION TO FIRE ATTACK & EXTINGUISHMENT
Removes smoke, gases, and heat from building
Facilitates entry of firefighters
Reduces obstacles that hinder firefighters
Increases visibility for quicker location of seat of fire

7. ADVANTAGES OF VENTILATION TO FIRE CONTROL
TS 10–7
ADVANTAGES OF VENTILATION TO FIRE CONTROL
Reduces mushrooming
Reduces flashover potential
Reduces backdraft potential
Controls fire spread

8. ADVANTAGES OF VENTILATION TO PROPERTY CONSERVATION
TS 10–8
ADVANTAGES OF VENTILATION TO PROPERTY CONSERVATION
Permits rapid extinguishment
Reduces water, heat, and smoke damage
Confines fire to an area
Allows salvage operations and fire control to take place concurrently

9. BACKDRAFT INDICATIONS
VS 10-2
Puffing
Smoke
Pressurized
Smoke Coming
From Small
Cracks
Black Smoke
Becoming Dense
Yellow-Gray
Darkened
Windows
Walls Too
Hot to Touch
Rattling
Windows
Dull Orange Glow
of Visible Fire
Hot Unbroken
Glass

10. TS 10–9
BACKDRAFT PREVENTION
Top (vertical) ventilation is the primary method of preventing backdraft.

11. LIFE SAFETY HAZARDS IN UNVENTILATED BUILDINGS
TS 10–11
LIFE SAFETY HAZARDS IN UNVENTILATED BUILDINGS
Obscurity caused by dense smoke
Presence of toxic gases
Lack of oxygen
Presence of flammable gases
Danger of backdraft
Danger of flashover and rollover

12. FACTORS DETERMINING HORIZONTAL OR VERTICAL VENTILATION
TS 10–12
FACTORS DETERMINING HORIZONTAL OR VERTICAL VENTILATION
Building type and design
Number and size of wall openings
Number of stories
Number of staircases, shafts, dumbwaiters, ducts, roof openings
Availability of exterior fire escapes
Exposure involvement

13. VENTILATION PROBLEMS: BASEMENTS
VS 10-4
VENTILATION PROBLEMS: BASEMENTS
• Need to Descend
through Heat and
Smoke
• Blocked or
Secured Outside Entrances
• Difficulty of Using
Natural Ventilation

14. VENTILATION PROBLEMS: WINDOWLESS BUILDINGS
VS 10-5
VENTILATION PROBLEMS: WINDOWLESS BUILDINGS
• Late Detection Delaying
Ventilation and Creating Backdraft Conditions
• Horizontal Ventilation
Difficult or Impractical
• Usually Require Mechanical Ventilation

15. VERTICAL FIRE EXTENSION
TS 10–13
VERTICAL FIRE EXTENSION
Opening for ventilation purposes before the fire is located may spread the fire to areas that otherwise would not have been affected.

16. VENTILATION OPENING LOCATION & SIZE FACTORS
TS 10–15
VENTILATION OPENING LOCATION & SIZE FACTORS
Availability of natural openings
Fire location
Building construction
Wind direction
Fire phase
Building condition
Building contents
Roof type and condition
Effects on fire
Effects on exposures
Attack crew’s readiness
Ability to protect exposures
Size

17. VERTICAL VENTILATION VS 10-6 Roof Opening (At least 4’ x 4’
[1.2 m x 1.2 m])

18. TS 10–16
VERTICAL VENTILATION
Opening the roof or existing roof openings to allow heated gases and smoke to escape to the atmosphere

19. PRE-VENTILATION SAFETY PRECAUTIONS
TS 10–17
PRE-VENTILATION SAFETY PRECAUTIONS
Consider type of building involved.
Consider location, duration, and extent of fire.
Observe safety precautions.
Identify escape routes.
Select place to ventilate.
Move personnel and tools safely to roof.

20. ROOF TYPES VS 10-7 Flat Mansard Shed Butterfly Hip Gable Arch Lantern
Gambrel

21. BASEMENT FIRES First extension commonly into the attic
TS 10–29
BASEMENT FIRES
First extension commonly into the attic
May be ventilated in a variety of ways:
Horizontal ventilation through ground-level or below-ground windows
Through interior vertical shafts (stairwells, hoistway shafts, etc.)
Mechanical ventilation through a hole in the floor near a ground-level door or window

22. TS 10–30
ELEVATED STREAMS
Can force air and gases back into building if not used properly
If projected just above the horizontal plane, are effective in subduing sparks and flying brands rising from ventilation opening and in reducing heat of thermal column
Should never be projected through the ventilation hole while firefighters are still inside building

23. VS 10-13
VENTILATION
Correct Application
Incorrect Application

24. FACTORS THAT CAN DESTROY VERTICAL VENTILATION EFFECTIVENESS
TS 10–31
FACTORS THAT CAN DESTROY VERTICAL VENTILATION EFFECTIVENESS
Improper use of forced ventilation
Excess glass breakage
Fire streams directed into ventilation holes
Skylight breakage
Explosions
Burn-through of the roof, floor, or wall
Additional openings between attack team and upper opening

25. HORIZONTAL VENTILATION
VS 10-14
HORIZONTAL VENTILATION
Wind Direction
Leeward
Windward
Fresh Air

26. HORIZONTAL VENTILATION
TS 10–32
HORIZONTAL VENTILATION
Venting of heat, smoke, and gases through wall openings such as windows and doors

27. HOW HORIZONTAL FIRE EXTENSION OCCURS
TS 10–34
HOW HORIZONTAL FIRE EXTENSION OCCURS
Through wall openings by direct flame contact or by convected air
Through corridors, halls, or passageways by convected air currents, radiation, and flame contact
Through open space by radiated heat or convected air currents
In all directions by explosion or flash burning of fire gases, flammable vapors, or dust
Through walls and interior partitions by direct flame contact
Through walls by heat conduction through beams, pipes, or other objects that extend through walls

28. HORIZONTAL EXTENSION KEY POINTS
TS 10–35a
HORIZONTAL EXTENSION KEY POINTS
Wind is helpful but too much wind can be detrimental.
Windward — Side of building the wind is striking
Leeward — Opposite side of building
Horizontal ventilation may block escape of occupants.
There is an ignition hazard to higher portions of the fire building posed by rising heated gases.

29. HORIZONTAL EXTENSION KEY POINTS (cont.)
TS 10–35b
HORIZONTAL EXTENSION KEY POINTS (cont.)
Do not open building until charged lines are in place at attack entrance point, where fire might be expected to spread, and in positions to protect exposures.
Take precautions against upsetting horizontal ventilation.
First open a door on leeward side to create a normal process of thermal layering.
Know that opening doors between fire fighting crews and exit point reduces intake of fresh air.

30. UPSETTING HORIZONTAL VENTILATION
VS 10-15
UPSETTING HORIZONTAL VENTILATION

31. TS 10–36
FORCED VENTILATION
Ventilation accomplished mechanically (with fans) or hydraulically (with fog streams)

32. PORTABLE FAN SAFETY MEASURES
TS 10–37
PORTABLE FAN SAFETY MEASURES
Shut down before moving.
Carry by handles.
Clear personnel from area before starting.
Do not place where clothing, draperies, or curtains can be drawn into fan.
Avoid the discharge stream: heat and particles may be projected by venting equipment.

33. ADVANTAGES OF FORCED VENTILATION
TS 10–38
ADVANTAGES OF FORCED VENTILATION
Ensures more positive control of fire
Supplements natural ventilation
Speeds removal of contaminants
Reduces smoke damage
Promotes good public relations

34. DISADVANTAGES OF FORCED VENTILATION
TS 10–39
DISADVANTAGES OF FORCED VENTILATION
May cause fire to intensify and spread
Depends upon a power source
Requires special equipment

35. TYPES OF FORCED VENTILATION
VS 10-16
TYPES OF FORCED VENTILATION
Positive Pressure
Horizontal Mechanical
Hydraulic

36. FORCED VENTILATION MECHANICAL NEGATIVE PRESSURE
VS 10-17
FORCED VENTILATION MECHANICAL NEGATIVE PRESSURE
Wind Direction
Intake
Opening
(Optional
In-Blowing
Ejector)
Closed Doors
Smoke Ejector
(Exhaust)
Draft Path
Salvage Cover
Or Tarp
Blocking
Opening
Around Ejector
Pressure Inside Building
Lower Than Outside Building

37. FORCED VENTILATION MECHANICAL POSITIVE PRESSURE
VS 10-18
FORCED VENTILATION MECHANICAL POSITIVE PRESSURE
High
Power
Fan
Exit
Opening
(Same Size As
Entry Opening)
Closed
Doors
Draft Path
Pressure Inside Building
Higher Than
Outside Building
Cone Covering
Entire Door
Opening

38. ADVANTAGES OF MECHANICAL POSITIVE-PRESSURE VENTILATION
TS 10–40a
ADVANTAGES OF MECHANICAL POSITIVE-PRESSURE VENTILATION
No need to enter smoke-filled environment
Effectively supplements both horizontal and vertical ventilation
Allows for efficient removal of smoke and heat
Does not effect building contents or smoldering debris
Is faster than negative-pressure ventilation

39. ADVANTAGES OF MECHANICAL POSITIVE-PRESSURE VENTILATION (cont.)
TS 10–40b
ADVANTAGES OF MECHANICAL POSITIVE-PRESSURE VENTILATION (cont.)
Does not interfere with ingress or egress
Is easier to clean and maintain positive- pressure than negative-pressure fans
Is applicable for all types of structures
Allows for directing heat and smoke away from unburned areas or paths of exit

40. DISADVANTAGES OF MECHANICAL POSITIVE-PRESSURE VENTILATION
TS 10–41
DISADVANTAGES OF MECHANICAL POSITIVE-PRESSURE VENTILATION
Requires an intact structure
May increase interior levels of carbon monoxide
May extend hidden fires

41. GUIDELINES FOR EFFECTIVE POSITIVE-PRESSURE VENTILATION
TS 10–42
GUIDELINES FOR EFFECTIVE POSITIVE-PRESSURE VENTILATION
Take advantage of existing wind conditions.
Make certain that cone of air from fan covers the entire entry opening.
Systematically open and close doors or increase the number of fans to reduce size of area being pressurized.
Keep size of exit opening in proportion to the entry opening.

42. FORCED VENTILATION HYDRAULIC
VS 10-19
FORCED VENTILATION HYDRAULIC
Fog Stream
(Covering 85%
90% of Opening
Nozzle Tip
(At least 2 ft. [0.6m]
Back from Opening)

43. HYDRAULIC VENTILATION
TS 10–43
Typically used to clear a structure of heat, smoke, steam, and gases following the initial knockdown of fire
Takes advantage of air that is drawn into the fog stream to help push the products of combustion out of structure
Fog pattern should be wide enough to cover 85 to 90 percent of the window or door opening through which the smoke will be pushed
Nozzle tip should be no closer than 2 feet (0.6 m) from ventilation opening

44. DISADVANTAGES OF HYDRAULIC VENTILATION
TS 10–44
DISADVANTAGES OF HYDRAULIC VENTILATION
May increase amount of water damage
Will put a drain on available water supply
In freezing temperatures, will increase ice in area surrounding building
Requires nozzle firefighters to remain in heated, contaminated atmosphere throughout operation
Operation may be interrupted if nozzle team has to leave the area