17- 01 Ventilation Flashcards
What is considered a mainstay of fire control?
controlling the air
What is the limiting factor in the involved fuel’s heat release rate?
available air
How can fire control be gained and maintained? (2)
- limiting ventilation
2. controlling flowpaths
What may change fire behaviour drastically in regards to ventilation? (3)
- exiting occupants
- changes in structural integrity
- FF ops
What is flowpath?
movement of heat/ smoke from higher pressure- lower pressure
What is fuel limited?
the heat- release rate (amount of energy released over time) is limited primarily by chemical/ physical characteristics of available fuels
What are key indicators of fuel limited fires? (4)
- incipient/ early growth fire
- high neutral plane (smoke layer)
- better visibility
- relatively low temperatures
What is hydraulic ventilation?
using water flow to draw air out of structure
What are examples of mechanical ventilation? (2)
- PPV
2. building systems
What are different types of ventilation? (3)
- hydraulic
- mechanical
- natural
What are examples of natural ventilation? (3)
- wind
- opening windows
- creating openings at highest point of structure
What is tactical ventilation? (6)
planned, systematic, coordinated removal of heat, smoke, fire gases and replacement with cooler fresh air
What is vent limited?
a fire in which heat release rate and fire growth are regulated by available O2 w/i space
What are indicators of vent limited fire? (7)
- fire is beyond incipient stage
- mid-low neautral plane
- poor visibility
- flames exiting windows/ doors
- air being drawn into fire when door opened
- increased temps
- all common backdraft indicators
What is ventilation profile?
ventilation points showing flow paths of heat and smoke out of structure as well as any air movement into structure