Chapter 16 - Ventilation Flashcards
Define - Ventilation
Ventilation, as applied to firefighting, is the planned and systematic, release and removal of heated air, smoke, and toxic gases from a confined area and the controlled replacement of these products of combustion with a supply of cooler, fresh air.
(blank) ventilation operations have become a necessity
Prompt
What are the Advantages of ventilation? (6)
Rescue ops
- RO are expedited as the atmosphere is made more tenable by the release of heat and toxic gases. This quickens the S&r ops and provides fresh air for the occupants of the building, reducing the danger of asphyxiation.
Fire attack
- fire can be found more rapidly and ex
Property damage
- water damage reduced, salvage initiated sooner, smoke damage reduced
Thermal layering
-reduces smoke and heat ff must endure while making interior attack
Backdraft / flashover
- potential for either can be substantially reduced
fire spread
-tends to localize the fire, thus reducing spread, vert vent controls mushrooming and horizontal vent can hold the fire to an area of the structure
page 7 chapter 16 for precise
Deciding where to Ventilate?
Location of fire Location of occupants Interior and exterior exposures Type of construction Purpose or use of occupancy Extent to which the fire has progressed Which direction you wish to draw the fire Condition of the building and its contents Existing openings Direction of the wind Available personnel and equipment Exposures
Two tools that may assist a ff in locating and deciding on where to ventilate are?
Reading the smoke condition
Thermal imaging camera
When reading smoke, the ff must consider four factors?
Volume
Velocity
Density
Color
Pertaining smoke describe:
Volume
Velocity
Density
Color
pg 9 ch 16
-Volume
Estimate volume of “box”
smoke will not escape low openings until “box” is full
-velocity (pressure)
As the box fills pressure grows and smoke is forced out. observe speed of the smoke exiting. faster speed, greater pressure and greater size of fire. velocity can indicate volume and or heat of fire
- Density (most important factor)
Smoke is denser, closer to the seat of the fire.
smoke diffuses as it drifts away
density can indicate likelihood of an event- flashover, smoke explosion. can also indicate stage or degree of fire - color
Various products produce diff colors.
may not always indicate true combust burning
Color of smoke?
Gray - wood and paper
Black - hydrocarbons, plastic
Brown/copper - Nitrogen Oxides
White - steam
Black fire - is the term we give to high volume, high velocity, and extremely dense, black smoke. it is a sure indicator of impending flashover.
your only choices are to VENT and COOL
Firefighters will encounter _____ types of exposures?
2
Internal
External
Types of Tactical Ventilation
Vertical
Horizontal
Vert and Horiz Vent can be achieved through _____, ________ and ________ means
Natural, Mechanical, and Hydraulic
Types of roof vent openings?
Kerf Cuts - slot cuts to determine direction of fire spread
Inspection Cuts - Small triangles
Louvered cuts - Large rectangular openings
