LOS ANGELES COUNTY FIRE DEPARTMENT CONTEXT TRAINING PROGRAM VENTILATION

Transcription

1 LOS ANGELES COUNTY FIRE DEPARTMENT VENTILATION 2

2 3 VENTILATION A. GENERAL INFORMATION Ventilation consists of the procedures necessary to effect the planned, systematic direction and removal of smoke, heat and fire gases from a structure. B. NATURAL VENTILATION As a fire burns in a building, the fire floor is filled with the hot products of combustion that rise and fill all of the available spaces in the building. Natural ventilation currents can be used to ventilate such a building very easily. This is accomplished by opening doors, windows, skylights and other available openings. In order for natural ventilation to be effective it is dependent on these factors: - Location of the ventilation opening relative to the contaminants. - Are there-any obstructions to the travel of contaminants? - The number and size of the ventilation openings. - Direction of the wind flow relative to the ventilation openings. - Relative humidity (damp, cold air will suppress natural air currents). - The temperature differential between the exterior and the interior of the building. C. ROOF VENTILATION Ventilation openings should be carefully selected and executed in a professional manner. A proper size-up will determine the size and placement of the ventilation openings required and minimizes any unnecessary damage to the structure. 1. Size up the fire building and locate the fire. 2. Develop a ventilation plan. a. Type of ventilation hole to be used. (Trench, etc.) b. Location of hole. c. Location of ladders. d. Directions of egress. (1) Primary route to ventilation site. (2) Secondary escape route.

3 4 ROOF VENTILATION - cont: e. Safety 3. Ladder the building. (1) The minimum team for roof operations is two people. (2) The supervisor should monitor the radio at all times. a. Use strong points of building. b. Ladder away from the fire. c. Do not block doors, windows or other openings with ladders. d. Consider the direction of the wind when selecting ladder locations. e. A second ladder will provide an escape route. 4. Size up the roof as to the type of covering and access locations. 5. Equipment should include: a. Sounding tool b. Radio c. Axes with belts d. Chain or rotary saw with equipment bag and fuel. e. Pike pole (Can be substituted as a sounding tool.) f. Lights g. Drop bag h. Other items per pre-plan information 6. Brief the crew as to the ventilation plan. 7. Start the saw prior to taking it to the roof.

4 5 ROOF VENTILATION - cont: 8. Place the ladders. 9. The first member to the roof should sound the area and secure the ladder. 10. Proceed to the ventilation site using the proper sounding techniques. 11. Use kerf cuts every 20 feet or so to-assess the situation below you. 12. If possible use existing roof hatch covers or skylights rather than cutting ventilation holes. 13. At the ventilation site make an inspection cut to determine the roof covering, rafter direction and the fire situation below the crew. 14. The completed ventilation hole should be large enough that the products of combustion are no longer venting under pressure. 15. Use a pike pole or sounding tool to clear obstructions below. 16. When the ventilation operation has been completed, notify the I.C. 17. Exit the roof: a. Follow the same path used to approach the ventilation site. b. Sound the roof on the way out. D. POSITIVE PRESSURE VENTILATION 1. Place blowers far enough from the doorway or ventilation access point to completely cover the opening with a cone of air. (This can be checked with a bare hand.) 2. Tilt the blower 20 to 30 degrees to increase air flow to upper levels. 3. For large, horizontal openings, blowers can be used side by side to cover the opening. 4. For large buildings, -blowers can be placed in tandem with the largest capacity blower 2 feet from the opening and the other providing the cone over the entrance.

5 6 POSITIVE PRESSURE VENTILATION cont: 5. In single story construction start ventilation nearest the fire. 6. In multi-story construction start at the lowest elevation. 7. Exhaust openings should be opened one at a time so the air flow will creates a venturi effect and evacuate the smoke from the room. Using more than one exhaust opening will, dissipate the flow of air and reduce the overall effectiveness of the ventilation efforts. 8. Exhaust openings should be from 3/4 to 1 3/4 the size of the entrance opening. 9. If exhaust fumes are detected in the building the exhaust opening is too small. 10. A small capacity blower requires a smaller exhaust opening than a large capacity blower. 11. Clear screens and draperies from the exhaust openings. 12. If the intensity of the fire increases, discontinue positive pressure ventilation. E. USING A FOG NOZZLE FOR SMOKE REMOVAL A fog stream directed through a window or door opening will draw large quantities of heat and smoke in the direction the stream is pointed. Fog streams have been found to remove 2 to 4 times more smoke, than mechanical smoke ejectors. 1. Position a 1 3/4" hose line approximately 2 feet in front of the exhaust opening. 2. A nozzle with a 60-degree angle fog pattern provides the best results: a. The pattern should cover 85 to 90 percent of the opening. b. Provide an unobstructed opening for incoming air. c. Water damage and runoff are the primary concern. REFERENCES: Essentials, Ventilation Methods and Techniques and Fire Command.

6 7 OBJECTIVE: 1. Demonstrate the ability to safely and efficiently ventilate a building in coordination with firefighting operations. 2. To answer general information questions about ventilation operations. 3. To demonstrate ventilation methods utilizing proper techniques. EQUIPMENT: 1. Ladder 2. Sounding Tool 3. Axes with belts 4. Chain or rotary saw with equipment bag/fuel 5. Pike pole 6. Lights 7. Drop bag 8. Radio 9. Fireline tape or streamers can be placed in windows and be used to in coordination with firefighting operations. DESCRIPTION OF EVOLUTION: 1. All personnel will have personal safety equipment donned and S.C.B.A. ready for use. 2. Answer questions about ventilation. 3. Assemble the ventilation group and obtain the necessary equipment. 4. Develop a ventilation plan. 5. Execute the plan and assess its effectiveness. 6. Re-assemble at the base of the ladder and notify the IC that the ventilation group task has been completed.

7 8 UNIT STATION SHIFT DATE NAME NAME NAME NAME RANK RANK RANK RANK INDIVIDUALS NOT MEETING THE COMPANY SKILLS STANDARD WILL REQUIRE ADDITIONAL TRAINING IN THAT SKILL. COMPANY HAS MET THE STANDARD: YES NO COMMENTS: 1. Develop a ventilation plan: a. The crew leader conducts a size-up of the building and develops a ventilation plan in coordination with the I.C. b. Offensive or defensive ventilation. c. Discuss the ventilation plan with the crew and make individual assignments where needed. RATER DATE

8 9 COMPANY HAS MET THE STANDARD: YES NO COMMENTS: 2. Commence ventilation operation: a. Ladders placed correctly. b. Start the saw on the ground. c. First member-up sounds the roof. d. Secure-the ladder. f. Sound roof, approaching ventilation site. g. Make kerf cuts every 20 feet. i. Use existing openings if possible. j. Cut the ventilation hole according to plan. k. Clear below cut as needed. l. Evaluate the effectiveness of the hole. m. Notify the I.C. when completed. n. Exit the roof in a safe manner. RATER DATE

9 10 POSITIVE PRESSURE VENTILATION COMPANY HAS MET THE STANDARD: YES NO COMMENTS: 3. Placement of blowers in doorways and openings: a. Cone of air covers the-opening. b. Parallel method - two or more blowers are used to cover a large horizontal opening. c. Tandem method - the largest blower 2 feet from the opening, the second blower will provide the cone over the opening. d. 20 to 30 degree tilt on blower. e. Clear one room at a time. f. Exhaust openings are ¾ to 1 ¾ the size of the intake openings. g. Start close to the seat of the fire. h. Clear ventilation holes of obstructions. i. Evaluate ventilation effectiveness. j. Notify the I.C. that ventilation operations have been completed. RATER DATE

10 11 RATERS ASSESSMENT QUESTIONS 1. Ventilators on the roof that are spinning from the pressure of the fire below are more efficient then ventilators that are removed by fire-crews. 30% 2. What should the ventilation crew do if after opening a ventilation hole the smoke continues at a high volume and the interior members report no relief? Expand hole 3. A good ventilation plan will cover? Ladder placement; type of ventilation operation; escape routes. 4. What does an inspection cut reveal? Type of construction, roof covering, fire conditions. 5. When using positive pressure ventilation on a multistory building the sequential operation should start? At the bottom. 6. Tilting the blower degrees assists the positive pressure ventilation operation. 20 to 30 degrees. 7. What should you do when you detect the odor of gasoline or exhaust fumes in a building being pressure ventilated? Increase the exhaust opening. 8. What are the benefits of using positive pressure ventilation during overhaul operations? It removes carbon monoxide and other gases, reduces the heat and it is more effective than trying to draw the smoke out of the building with a smoke blower. 9. The cone of the fog nozzle pattern, that is being used for ventilation, should cover what percentage of the opening to be exhausted? 85 to 90%

11 12 INSTRUCTIONS: The Battalion information recorded on this form shall be a combination of all three shifts Informally Evaluated by the Battalion Chiefs. This form is to be submitted by 1. The total number of Battalion personnel that participated in the Informal Evaluation are: 2. The total number of people that were unable to complete the Informal Evaluation is: 3. List any problems encountered in the Informal Evaluation: ALL RANKS ALL RANKS 4. List additional feedback on the Context Training Program: Prepared by: Division: Battalion: Reviewed by: Distribution: Original to Battalion Chief files 2 copies to jurisdictional Assistant Chief Rev. 9-01