Essentials of Fire Fighting , 5 th Edition

1. Essentials of Fire Fighting, 5th Edition Chapter 11 — Ventilation Firefighter I

2. Chapter 11 Lesson Goal • After completing this lesson, the student shall be able to identify reasons and needs for various types of ventilation within a structure, distinguish which types of ventilation are most effective to varying situations, and perform duties related to ventilating a structure following the policies and procedures set forth by the authority having jurisdiction (AHJ). Firefighter I

3. Specific Objectives 1. Describe reasons for fireground ventilation. 2. List considerations that affect the decision to ventilate. 3. Discuss factors that are taken into account when deciding the need for ventilation. (Continued) Firefighter I

4. Specific Objectives 4. Discuss vertical ventilation. 5. List safety precautions to observe when undertaking vertical ventilation. 6. List warning signs of an unsafe roof condition. (Continued) Firefighter I

5. Specific Objectives 7. Discuss roof coverings and using existing roof openings for vertical ventilation purposes. 8. Discuss ventilation considerations for various types of roofs. 9. Describe trench or strip ventilation. (Continued) Firefighter I

6. Specific Objectives 10. Explain procedures for ventilation of a conventional basement. 11. List factors that can reduce the effectiveness of vertical ventilation. 12. Discuss horizontal ventilation. (Continued) Firefighter I

7. Specific Objectives 13. Discuss considerations for horizontal ventilation. 14. Distinguish between advantages and disadvantages of forced ventilation. 15. Discuss negative-pressure ventilation. (Continued) Firefighter I

8. Specific Objectives 16. Discuss positive-pressure ventilation. 17. Compare and contrast positive-pressure and negative-pressure ventilation. 18. Describe hydraulic ventilation. (Continued) Firefighter I

9. Specific Objectives 19. List disadvantages to the use of hydraulic ventilation. 20. Explain the effects of building systems on fires or ventilation. 21. Ventilate a flat roof. (Skill Sheet 11-I-1) (Continued) Firefighter I

10. Specific Objectives 22. Ventilate a pitched roof. (Skill Sheet 11-I-2) 23. Ventilate a structure using mechanical positive-pressure ventilation. (Skill Sheet 11-I-3) 24. Ventilate a structure using horizontal hydraulic ventilation. (Skill Sheet 11-I-4) Firefighter I

11. 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 (Continued) Firefighter I

12. 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

13. 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 (Continued) Firefighter I

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

15. 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 (Continued) Firefighter I

16. 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 (Continued) Firefighter I

17. Fire Spread Control Reasons for Fireground Ventilation Firefighter I

18. Reduction of Flashover Potential Reasons for Fireground Ventilation • Flashover • 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 (Continued) Firefighter I

19. 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 (Continued) Firefighter I

20. 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

21. 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 (Continued) Firefighter I

22. 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

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

24. 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 (Continued) Firefighter I

25. 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

26. 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

27. 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 (Continued) Firefighter I

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

29. 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

30. 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

31. 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. (Continued) Firefighter I

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

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

34. 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 (Continued) Firefighter I

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

36. Basements and Windowless Buildings Firefighter I

37. 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 (Continued) Firefighter I

38. 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

39. 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 (Continued) Firefighter I

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

41. DISCUSSION QUESTION Why is it important for ventilation to be coordinated with other operations such as fire attack? Firefighter I

42. Vertical Ventilation • Opening roof/existing roof openings for allowing heated gases, smoke to escape • Firefighters must understand basic types, designs of roofs (Continued) Firefighter I

43. Vertical Ventilation • Firefighters must know how roofs in the response areas are constructed (Continued) Firefighter I

44. Vertical Ventilation — Preincident Inspections • Identify • New construction projects • Existing construction • Use of lightweight building materials • Information that can alert firefighters Firefighter I

45. Likelihood of Roof Collapse During Vertical Ventilation • Based on • Volume of fire • How long fire has been burning • Type of construction • Level of protection • Load on roof Firefighter I

46. Responsibilities During Vertical Ventilation — Officer in Charge • Determine it can be done safely, effectively • Consider age, type of construction • Consider location, duration, extent of fire • Observe safety precautions (Continued) Firefighter I

47. Responsibilities During Vertical Ventilation — Officer in Charge • Identify escape routes • Select place to ventilate • Move personnel, tools to roof Firefighter I

48. Responsibilities During Vertical Ventilation — Leader on Roof • Ensure roof safe to operate on • Ensure only required openings made • Direct efforts to minimize secondary damage • Coordinate crew’s efforts with firefighters inside building (Continued) Firefighter I

49. Responsibilities During Vertical Ventilation — Leader on Roof • Ensure safety of all personnel • Ensure team leaves roof as soon as assignment completed Firefighter I

50. Safety Precautions During Vertical Ventilation • Check wind direction with relation to exposures • Work with wind at back/side to provide protection while cutting • Note existence of roof obstructions/excessive weight on roof (Continued) Firefighter I