CVFD Training – Ventilation Practices SFFMA Training Objectives: 8-01.01 – 8-01.04

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

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

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

Fire Attack and Extinguishment Reasons for Fireground Ventilation Firefighter I

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

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

Fire Spread Control Reasons for Fireground Ventilation Firefighter I

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 (Continued) Firefighter I

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Basements and Windowless Buildings Firefighter I

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

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

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

Selecting Place to Ventilate Many considerations before ventilating building Firefighter I

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

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

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

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

Horizontal Ventilation Considerations — Exposures Internal — Include building occupants, any uninvolved rooms/portions of building External (Continued) Firefighter I

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 (Continued) Firefighter I

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 (Continued) Firefighter I

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 (Continued) Firefighter I

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

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 (Continued) Firefighter I

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

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