Tactical Ventilation and Fire Behavior

Question Answer Planned systematic and coordinated removal of heated air smoke gases What is tactical ventilation and other airborne contaminants from a structure What does being in control of a fire mean Using ventilation and water application to control its behavior What occurs as oxygen inside a The fire burns less efficiently making a larger amount of unburned fuel room/structure get consumed products from incomplete combustion What will happen happen to the combustion rate of a ventilation limited It will raise until water is applied fire What is an effective way of controlling Closing doors Covering opens ventilation What can occur when fresh air from ventilation is introduced into a fire room Heated gases can ignite Rapid fire development. What must you do to prevent rapid fire Use appropriate water streams to cool heated gases Properly release development. gases with correct ventilation at the correct time What will lead to flashover Ventilation without coordination What amount of ventilation will cause the fire to become fuel limited/prevent Not possible flashover What are the characteristics of gases Buoyant Tend to rise Move toward low pressure areas that are less dense then air What is the primary mode of heat transfer from one compartment to Convection another in a structure fire What conditions can tactical ventilation Increased oxygen concentration Reduced heat, products of combustion done properly create Increased visibility Who does the life safety priority apply to Occupants in the structure and the firefighters fighting the fire What can be used to alter a flow path Coordinated ventilation away from victims When should tactical ventilation be When lines are charged Attack lines are in place Attack crew is ready applied What should be done to prevent fire Keep the fire ventilation limited for as long as possible spread What can happen before ventilation is Any rescue/search initiated What are some conditions that should be Overhead power line Solar panels Guide wires Two escape locations off communicated to an IC or supervisor roof when tasked with tactical ventilation What are examples of unplanned ventilation What are the two assumptions firefighters should make about any structure fire toguide decision making What can allow the atmosphere to influence the fire in a building How should firefighters use wind to their advantage at a fire What Speed of winds can affect structure fires What must firefighters consider before tactical ventilation operations occur for exposures What is a hazard with exhausting smoke through a mid or lower level opening How can heat/gases enter adjacent buildings What is the main cause of adjacent buildings being affected by a structure fire Window failure Doors opened or fail Structural member failure Structure consists of lightweight construction Fire is Ventilation limited Any opening in the building Work the with wind to your back Entrance upwind Exhaust downwind 10 mph or more Interior exposures (occupants, contents, uninvolved rooms) External exposures (adjacent buildings, exterior walls) Can ignite exterior walls or roofing of building Can go into adjacent buildings and ignite Drawn into attic vents and HVAC systems Enter through open windows Radiation Direct flame contact What should be gathered when spectating where to ventilate What is your responsibility when you see observations or concerns What are some examples of structural elements that can cause an issue/lack of integrity What are some indications of possible roof collapse What should a spongy roof do What can a spongy roof indicate What are axes used for What are power saws used for What are chain saws used for What are pike poles used for What are air movement devices used for What are hoselines and nozzles used for in terms of ventilation What is a wind control device What is a smoke control device Information about fire, building, and occupancy To communicate them Lightweight trusses Open floor plans with limited truss supports Prior damage to the roof Melting asphalt Smoke/fire coming from roof Roof systems sagging/leaning Spongy roof Sag when pushed or waked on but spring back into shape Failure of roof decking Breaking windows Chopping holes through roof decking Cutting holes through roof decking Cutting holes through roof decking Pulling or opening ceilings Generate air flow Hydraulic ventilation and resetting fire Heavy curtain used to cover exterior window and door openings to limit ventilation Heavy curtain or similar device used to block interior or exterior window and door openings to limit ventilation Downwind side openings should be made first to create an exhaust point Upwind side openings made second to create intakes How should wind assisted ventilation operations go How much time does natural ventilation Less than a minute alone provide better conditions When is mechanical ventilation needed When natural air currents aren’t enough to ventilate properly Artificially lowering the pressure inside the structure so fresh air from What does negative pressure mean outside moves in quickly Artificially raising the pressure inside the structure so that smoke and What does positive pressure mean gases move toward the lower pressure exterior Opening a door or window on the upwind side before creating exhaust What can upset horizontal ventilation point What does mechanical horizontal Accelerated exchange of fresh air into a structure Not under control, ventilation do when applied before/ can do more harm than good during fire suppression What are some limitations of mechanical Depends on power source Requires special equipment and more ventilation resources Why should firefighters wear SCBA and monitor the environment when doing Gas powered fans can add carbon monoxide to a structure overhaul with a fan Supplements/enhances natural ventilation Ensure more control of air What are some advantages of flow Speeds the removal of contaminants Reduces smoke damage mechanical ventilation Promotes good public relations How is negative pressure ventilation performed How do you set up an NPV fan Air movement equipment develops artificial air flow to pull smoke from the structure and bring fresh air into it With a seal around the outside of it preventing outside air from being drawn in What does a positive pressure attach work best on What will happen if the pressure is not sufficient during a Positive Pressure Attack Fires confined to a single compartment What is positive pressure attack Controlling the flow within a structure during the initial stages of a fire before suppression occurs What are the two main consideration when performing a PPA Location of fire Exhaust to intake size ratio (at least 1 to 1) What is positive pressure ventilation Exhausting smoke heat and toxic gases to the exterior after fire suppression Smoke will exhaust towards PPA intake instead of exiting out the exhaust point What are disadvantages of PPV What should be done to ensure an effective PPV operation What are some advantages of PPV May hide fire extension Smoldering fires can intensify Structure must have some compartmentalization Carbon monoxide added through fan exhausts Exhaust surface area exceeds intake surface area Maintain communication Take advantage of wind direction Firefighters don’t have to enter IDLH Equally effect with horizontal and vertical ventilation Heat/smoke removal is efficient When using PPV on a multistory building Lowest point or ground level where should the fan be located What is main problem for using PPV in Coordinating the opening and closing of the doors in stairwells multistory buildings Water damage increased if done incorrectly Depleted water supply What are some disadvantages of More ice in cold conditions Firefighter operating nozzle must remain in hydraulic ventilation IDLH What increased risks does vertical ventilation create What are some factors that can reduce the effectiveness of vertical ventilation What are some safety precautions for vertical ventilation What should be done before stepping of a ladder into a roof What information does sounding provide about structural members of the roof beneath the sheathing What roofs may not respond to sounding What roofs can’t be sounded What must be done in order for ventilation to occur on slate or tile roofs How should a saw be transported to an from the point of operation What should be done before cutting any type of ventilation hole What can an inspection hole determine What are the two primary types of inspection holes Whay information can a kerf cut give firefighters What should happen if flames come through an inspection cut How can a ventilation cut be made What cut is used when the truss is in the middle of a cut Where should you cut your ventilation hole on a pitched roof What is the purpose of a trench cut When is a trench cut used What should be present when a trench cut is being made What should have already happend if a trench cut is Being used What are the advantages of a trench cut What are some disadvantages of a trench cut What is something that is very important when considering ventilation for a basement fire than other fires Personnel above ground level Working on peeked and flat roofs Working above fire Working on weakend roofs Improper use of mechanical ventilation Uncoordinated ventilation Fog streams directed into vent holes Burn through of the roof Improper location of ventilation hole Additional ventilation openings Work with the wind at your back or side when cutting Extend ground ladders at least three rings above the edge of the roof or parapet Sound the roof None Roofs with multiple layers of roofing materials Slate or tile roofs They must be removed from roof exposing sheathing Off Cut an inspection hole Location of fire Presence of fire below the roof Construction features Kerf cut Triangle cut Wether or note smoke or flames is escaping from the cut Abandon ventilation efforts and exit the roof Report to IC Between trusses or with trusses in the middle of the cut Louver cut Few inches below the peak on the downwind side At or near highest point on the roof To create a defensible line ahead of the fires spread When the IC determined the main body of the fire is too large to extinguish Charged hoselines A ventilation hole over body of fire has already been made Works well in large buildings Creates defensible space in attic Time consuming Physically taxing Place firefighters ahead of the fire Can cause fire to spread more rapidly The stage of the fire What is a last resort to ventilate basement fires What do windowless building usually require for proper ventilation What is a specific risk to high rise fires Explain the stack affect Cutting a hole in the flooring near a door or window to use as an exhaust opening Mechanical ventilation Fire, smoke and toxic gases can spread rapidly through pipe chases, stairways, elevator shafts, unprotected ductsX and other vertical openings Heated smoke and fire gases travel upward until they reach the top of the building or they are cooled to the temperature of air, smoke and fire gases stop rising and start to spread horizontally and stratify into layers When else can horizontal smoke spread When ventilation holes are to small occur What stairwell should be used for The one that penetrates the roof ventilation in high rise buildings What should be deployed on a stairwell A PPV to pressurize stairwell so it doesn’t fill with smoke that is being used to evacuate occupants