2 GoalGiven information on ventilation the firefighter will be able to identify when and where to safely apply ventilation so that heat, smoke, and gases can be removed from a structure to improve conditions for fireground operations. This will be done to a written test accuracy of 75% and complete the practical evolutions in the allotted time to the instructor’s satisfaction.
3 Objectives The student will: Understand the importance of ventilation.Be able to identify when and where to ventilate.Understand the dangers of ventilation.Be able to identify the different types of roof construction.
4 Objectives Con’t Know the the different tools used for ventilation. Understand the compilations of ventilationHave an understanding of positive and negative pressure ventilation.Know how to explain and perform vertical ventilation.
5 Objectives Con’t Know how to explain and perform natural ventilation. Know how to explain and perform horizontal ventilation.
6 Overview Importance of ventilation Different techniques Advantages and disadvantagesPrecautions and dangersRoof Types, and their constructionDifferent types of ventilationTools needed for ventilation
7 VentilationThe systematic removal and replacement of heated air, smoke, and gases from a structure with cooler air
8 Advantages Rescue Increases survivability of trapped victims Improves visibility, and reduces heat levelsReduction of flashover and backdraft potentialFire attackFire spread controlProperty ConservationRescueReplaces heat, smoke and gases with cooler, fresher airImproves visibility to locate and remove victimsFireLocation of fireLowers danger of firefighters injuries and burnsVisibilityRemoval of smoke and replacement of fresh airProperty conservationAllows quicker extinguishment reducing future damageBackdraft and flashover potentialRemoval of super heated air and gasesKnow the signs, and ventilate properlyFire spreadReduces mushrooming , relieving the heated gases and smokeIncreasing survivability for victimsReplaces heat, smoke and gases with cooler, fresher airSurvivable atmosphere until rescued
9 Disadvantages or Improper Ventilation Fire spreadAccelerated burningPuts firefighters in dangerTriggers BackdraftStructural IntegrityLack of communicationWrong locationTo soonVenting behind firefightersWeaken structure integrityCutting through floor joist, rafters, studs, etc.
10 Dangers of ventilations Light weight construction.Can cause fire to intensify and spread.Places firefighters in danger.Backdrafts.Weather conditions.Weakens and fails quicklyProvides fuelOpen areas for fire spreadWorking on weakened roofs or floors.Venting incorrectlyWind, rain, snow, ice, electrical storms. (FROST)
11 Complications Lack of Pre-planning Barred/Screen windows. Overhead obstructions.AccessWeatherImproper equipmentMan powerPreplans – Roof construction such as Parapet wall, Mechanical equipment, Concrete Pre-cast, Pre-stressed, poured reinforced or light weight, metal decking, double roofsOverhead – Wires, trees, Other bldgs.Weather – Lighting, Wind, Rain, Snow, Ice, etc.Equipment – Saw blades, Not ready for the job (Out of gas), Dull/dirty ax blade.Man power – Air supply to do the jobPower and other wires overhead.Antennas
12 Complications (Con’t) VisibilityRoof pitch/typeVisibility – Heavy SmokeConstruction – Parapet wall, open hatches, stairwaysStep pitched roofs or less can be walkedSlate, tile shingles built-up, metal, etc.
13 ? Ventilation Where When How Cooler air improve firefightering operations, life safety for rescue, conditions for trapped occupants. And reduces conditions that support Flashover and Backdraft.In newer home ventilation has to be performed quicker.(Energy Efficient)PlasticsHow
14 Ventilation Size-up Is there a need. (Why) Where is it needed. (Where) Type needed. (How)Structural conditions allow for safe operations.Timing (When)NEEDWhat are the conditions in the structure. (Heat,fire,smoke etc.)Life hazards. (Type of structure, Commercial, Assembly, Medical, Dormitory - Hood, MSD.)Structural stabilityAre you actually causing unnecessary damage. (Pre-existing openings)WHERELocation of fire.Wind directionLocation of victims and escape routes.Bldg. construction (Concrete, Wood, Roof type, High rise)Structural integrity, Wreaking roofLocation of pre-existing openings. (Sky lights, HVAC, Exhaust fans, Windows and doors)Exposures, Contents (Are you endangering other bldgs or it’s contents)Fire spreadPreplanningTYPEHorizontalVerticalNaturalMechanical
15 Coordinated Fire Attack Vent as close to the point of origin as possible coordinating with interior attack crew.Hose line ready and charged while firefighters are advancing.Ventilation of the fire room with outside vent person.Most direct routeDecrease property lossEasier for attackLessens the physical demand on you.Fire can intensifyCause more structural and property damageVentilation can be done from inside if needed
16 To keep smoke, heat, and gases away from victim. Primary ConsiderationRESCUEORSUPPRESSIONPRIORITYWITH INTERIOR ATTACKTo keep smoke, heat, and gases away from victim.To reduce heat andIncrease visibilityFor firefighters
17 Types of VentilationNaturalHorizontalVerticalMechanical
18 Natural Ventilation – The means of ventilating a structure without the assistance of powered equipment.
19 Natural VentilationWind.Currents created by the fire.Use Caution!!!
20 Horizontal Ventilation – Is the venting of heat, smoke and gases through wall openings such as windows and doors.
22 Horizontal Ventilation Uses:ResidentialMultistoried structuresLarge unsupported open spaces.Residential – Fire/smoke not involving the attic.Multistoried Structure – Fire not involving top floor or attic.Unsupported open spaces that have been damaged by fire weakening the roof structure.
23 Vertical VentilationOpening the roof or using existing roof opening to allow heated gases and smoke to escape.
24 Natural Opening Sky lights Scuttle Hatches Windows Doors Shafts VentilatorsStairwaysUse natural openings before cutting if possibleMay be used to supplement an opening you have to cut
25 Roof openings Cut large opening Smaller openings Trench cut Minimum 4’x4’Windward sideSmaller openingsMay be necessary do to conditionsTrench cutFrom Exterior wall to exterior wall4’ wideOne large is more effective than several small ones.Small openings may have to be used do to conditions of structure
26 Vertical Ventilation Uses: Attics Areas open to the roof Cathedral ceiling, Churches, auditorium, A-frame, etc.Punch out ceilings to make open to roof
30 Positive-pressure ventilation (PPV) Induces fresh air into a confined area or structure resulting in an increase of pressure in that area which forces contaminated air through pre-selected and/or controlled openingsMust coordinate with operation, and attack crewsCan cause fire spread, and intensityCan trap firefighters, and or victims
31 PPV Advantages Two times more effective than NPV Does not block doorwaysDoes not expose personnel to contaminants while positioning blowerProvides fresh air, reduces heat, and CARBON MONOXIDE during overhaul operationsMust keep personnel out of the path of air movementMust assure of proper exhaust openings.
32 Disadvantages Noisy Not effective if there are to many openings Can cause fire spread, or ignite smoldering embersRaise CO levels with gas fans.Very loud at fan locationNot effective if there are to many openingsCauses fire spread if:Timing is offLocation is wrongBuilding construction- voids spaces, balloon frame etc.Gas fans can raise CO levels. However by regulating exhaust opening that can be lowered.
33 PPV Fan PlacementA single fan should be placed so the cone of pressurized air JUST covers the openingTilting the fan back about degrees will enhance the operationSquare box type fans can be stacked to achieve the same effect.( one fan on top of the other)
34 Back far enough to seal the opening Single unit operationExhaust opening should b ¾’s to twice the size of entranceEXHAUSTPATHBack far enough to seal the opening
35 YES!If you don’t have standard PPV blowers on your apparatus, simply use NPV devicesand stack them on top of each other, then reverse their positioning placing exhaust side in.- SMOKE EJECTORS -
36 PPV Fan PlacementTwo fans one in front of the other (series, tandem, or in line)Front fan (Largest) about 2 feet from opening, and the back fan will be set back far enough to cover the opening with pressurized airTwo or more fans side by side(parallel or dual)Fans should sit side by side and back far enough to cover the opening with pressurized air
37 Series, tandem, or in-line EXHAUSTPositive PressureDISTANCE2-3 feet Larger FanBack far enough to seal the opening
39 Exhaust openingMost effective when the exhaust opening is three quarters to two times the size of the entrance opening.Varies do to size of the fan or the amount of fans operating.Optimum efficiency is easily obtained by a combination of training and practical experience.
40 Determine PPV fan Size for a Given Structure Apply the PPV Rule of Thumb- Single family dwelling with up to 2,000 square feet: 18- to 21-inch fans- Ranchers and multistory dwellings up to 4,000 square feet: 24-inch fan- Larger structures (greater than 4,000 square feet) require multiple fan application with 2 to 3 24-inch fans- Always use multiple fans on high-rise structures 10 floors or greater
41 Negative-pressure ventilation Draws contaminates from interior to the exterior causing a negative-pressure in the contaminated area allowing fresh air to enter from an outside source through another opening.
42 Advantages Usually operates off of a 110 volt Usually explosion-proof motorEasily adapted to house outletsCan be used in an explosive atmosphere
43 Disadvantages Exposes personnel to the contaminated area Placement in doorways and windows require hangers, straps or other accessories to position them effectivelyBlock entrances and hallwaysContaminates are drawn through the fan causing additional cleanup and maintenanceExposes personnel to the contaminated areaPlacement in doorways and windows require hangers, straps or other accessories to position them effectivelyBlock entrances and hallwaysContaminates are drawn through the fan causing additional cleanup and maintenanceAdded noise levels in area of operations.
44 Mechanical Devices Gas Fan Electric Fan Mobile units HVAC systems Exhaust SystemsHose steams (Hydraulic)Gas FanElectric FanMobile unitsHVAC systemsExhaust SystemsHose steams (Hydraulic)
45 Gas Fans 2-cycle and 4-cycle engines 18 to 24 inch in diameter 3200 to 15,000 CFMMany different manufactures and stylesMaintenance ( Gas, oil, and air filters )Can cause CO levels to rise in structure2-cycle and 4-cycle engines18 to 24 inch in diameter3200 to 15,000 CFMMany different manufactures and stylesMaintenance ( Gas, oil, and air filters )Can cause CO levels to rise in structure
46 Electric Fans Both PPV and NPV Require electric cords NPV fans sizes 16 to 24 inch, from 2 to 3 hpSquare or circular encased, including motorPPV fans are 18 to 24 inch, from 3200 to 30,000 CFMBoth PPV and NPVRequire electric cordsNPV fans sizes 16 to 24 inch, from 2 to 3 hpSquare or circular encased, including motorPPV fans are 18 to 24 inch, from 3200 to 30,000 CFM
47 Mobile ventilation units DieselPTOHydraulic30,000 to 211,000 CFMDieselPTOHydraulic30,000 to 211,000 CFM
48 HVAC SystemsSome are designed to reverse to draw out contaminated air from buildingsMaintenance personnel from building will provide that informationIf unsure Turn units off.PreplanningSome are designed to reverse to draw out contaminated air from buildingsMaintenance personnel from building will provide that informationIf unsure Turn units off.Can move contaminants to other parts of buildingCheck units for fire extensionPreplanning
49 Exhaust Systems Some buildings have systems in place for other uses. Maintenance personnel from building will provide that informationPreplanningSome buildings have systems in place for other uses.Maintenance personnel from building will provide that informationPreplanning
50 Hose Stream (Hydraulic) Usually used in area of fire after knockdown to remove heat, smoke, and gasesUsing fog pattern at 85 to 90 degrees at least two from opening.Advantages:- Removal of contaminants prior to other mean of ventilation are startedDisadvantages:- Drawing contaminants over firefighter- Depleting water supply- Interfere with outside operations- Cause icing conditions during cold weather
51 Care and Maintenance PPV Blowers or Fans - Use proper oil and fuel mixtures- Keep belts tight and snug- Keep shroud(s) intact- Check fluid levels. Change fuel regularly and replace with fresh- Run blower- Keep rubber feet or base intactNPV Blowers or Fans- Clean blades and motor regularly- Keep electric cords and switches intact- Listen for any unusual noises during operationPPV Blowers or Fans- Use proper oil and fuel mixtures- Keep belts tight and snug- Keep shroud(s) intact- Check fluid levels. Change fuel regularly and replace with fresh- Run blower- Keep rubber feet or base intactNPV Blowers or Fans- Clean blades and motor regularly- Keep electric cords and switches intact- Listen for any unusual noises during operation
52 Contra indicators for PPV No properly trained crewWhen interior search or rescue teams or occupants are between the fire and exit point of smokeFor well-involved attic fires with no egress ventingWhen fire is present in the walls of balloon construction and no egress point is identifiedWhen backdraft conditions are evident.When the origin of fire is unknown.Too many openings in a structure preventing air flow from effectively pressurizing interiorNo properly trained crewWhen interior search or rescue teams or occupants are between the fire and exit point of smokeFor well-involved attic fires with no egress ventingWhen fire is present in the walls of balloon construction and no egress point is identifiedWhen backdraft conditions are evident.When the origin of fire is unknown.Too many openings in a structure preventing air flow from effectively pressurizing interior
53 Ventilating multiple floors Pressurize stair shaft common to all floorsStart with lower levels and work upVent horizontally through exterior openingsVent to opposite stair shaftPressurize stair shaft common to all floorsKeeps path of egress clear for firefightersKeeps contaminants from spreadingStart with lower levels and work upVent horizontally through exterior openingsDoorsWindowsVent to opposite stair shaftThen vertically out
55 Lightweight wood or metal joist Heavy steel trusses Wood “I” beams Roof ConstructionLightweight wood or metal joistHeavy steel trussesWood “I” beamsBuilt-up roofConcrete RoofsMetal roofsBuilt-up RoofUsed on residential or commercial buildings- Residential is usually apartment buildingsSolid wood rafters / lightweight wood or metal trussesPlywood sheathing / metal deckingTar, insulation, layers of composition and tar, gravel
56 Lightweight wood or metal trusses Trusses in place of raftersWood or metal deckingBuilt-up roofAllows horizontal fire spreadFails after 5-10 minutes of fire exposureTrusses in place of raftersWood or metal deckingBuilt-up roofAllows horizontal fire spreadFails after 5-10 minutes of fire exposure
57 Heavy steel trusses Metal decking with built-up roof Starts to fail at 1000 degreesMetal decking with built-up roofStarts to fail at 1000 degrees
58 Wood “I” beams Substitute for lightweight trusses Contributes fuel to the fireFails within 5 to 10 minutes of fire exposureSubstitute for lightweight trussesContributes fuel to the fireFails within 5 to 10 minutes of fire exposure
59 Concrete roofs Precast concrete Lightweight concrete Reinforced concreteTo vent this type is difficult and time consumingUse natural openings, skylights, scuttles, ventilators, stairwellsPrecast concreteLightweight concreteReinforced concreteTo vent this type is difficult and time consumingUse natural openings, skylights, scuttles, ventilators, stairwells
60 Metal roofs Light-gauge steel Corrugated galvanized sheet metal AluminumVent with power saws using metal cutting blades, axe, or sheet metal cutters.Use natural openingsLight-gauge steelCorrugated galvanized sheet metalAluminumVent with power saws using metal cutting blades, axe, or sheet metal cutters.Use natural openings
61 Flat Roof Industrial, commercial, and apartment buildings Frequently pierced by chimneys, vent pipes, shafts, scuttles, and skylightsMay be surrounded and or divided by parapetsMay have HVAC unit on themIndustrial, commercial, and apartment buildingsFrequently pierced by chimneys, vent pipes, shafts, scuttles, and skylightsMay be surrounded and or divided by parapetsMay have HVAC unit on them
62 Flat roof construction Wooden, metal, or concrete joistWooden or metal deckingWaterproof materials, insulation, gravelReinforced, lightweight concrete, or precast concreteWooden, metal, or concrete joistWooden or metal deckingWaterproof materials, insulation, gravelReinforced, lightweight concrete, or Precast concrete
63 Built-up roof construction GRAVELBuilt-up RoofUsed on residential or commercial buildingsSolid wood rafters / lightweight wood or metal trussesPlywood sheathing / metal deckingTar, insulation, layers of composition and tar, gravelOR PLYWOOD
64 Built-up Roof Opening built-up roof Remove gravel if present Make inspection cutCut insulation and composition down to deckingRemove materials, sound roof for rafters or bar joist, then cut decking and remove.Be careful not to cut to deep to avoid causing structural damage to the raftersRemoval of gravel only needed at starting pointsInspection cuts are to verify fire location and feasibility of ventilation- Is construction wooden joist or lightweight construction- Lightweight construction fails quickly under fire conditions- How to open roof (wooden or metal)Always work toward your except route.
66 Opening a flat roof Determining the location of the opening Location and extent of fireWind directionExposuresObstructionsOpen using the built-up roof method.Determining the location of the openingLocation and extent of fireWind directionExposuresObstructionsOpen using the built-up roof method.
67 Pitched Roofs Rafters or trusses 1X boards or plywood sheeting Felt paperShingles- wood, asbestos, composition, metal, slate or terracotta tile.May be gypsum slabs, approximately 2” thick, laid between metal trusses.Rafters or trusses1X boards or plywood sheetingFelt paperShingles- wood, asbestos, composition, metal, slate or terracotta tile.May be gypsum slabs, approximately 2” thick, laid between metal trusses.
69 Opening a pitched roofDetermine the location of the opening same as flat roofPlace roof ladder on the windward side of openingLocate the raftersCut opening working the farthest distance from you towards yourselfRemove the deckingPush a tool into the hole to open a possible ceiling belowDetermine the location of the opening same as flat roofPlace roof ladder on the windward side of openingLocate the raftersCut opening working the farthest distance from you towards yourselfRemove the deckingPush a tool into the hole to open a possible ceiling below
72 Opening an arched roof Cutting is the same as a pitched roof Use of a roof ladder would be unlikelyBecause of the potential for sudden collapse under fire conditions, roof operation should be done from an aerial ladder or tower.
73 Hand tools Axe Halligan bar Pike poles Sledge hammer Can opener Hand sawsLaddersAxe, TNT toolHalligan barPike poles, halligan hooks, etc.Sledge hammerCan openerHand sawsLadders
74 Power tools Vent saws Chain saws Circle saws Reciprocating saws Many makes and modelsGas or electricChain sawsCircle sawsWood, metal, and concrete bladesReciprocating sawsWood or metal blades
75 Power tool safety Proper maintenance Know tool operations and capabilitiesPPEStart tool before taking to operational areaNever carry, hoist, or climb while runningKeep front arm stiff while operating toolsWork with a partnerProper maintenanceChains or blades tight and sharpBrakes devices working properlyProper fuel, and oil levelsKnow tool operations and capabilitiesHow to startHow to change blades or chainsDifferent type blades, and their usesPPEStart tool before taking to operational areaNever carry, hoist, or climb while runningKeep front arm stiff while operating toolsPrevents injury from kick-backWork with partnerWatch your backStabilization
76 Review Discussed the importance of ventilation Discussed ventilation techniquesDiscussed the advantages and disadvantages of ventilationDiscussed precautions and dangers of ventilationDiscussed the different types of roofs, and their constructionDiscussed different types of ventilationDiscussed the tools needed for ventilation