Ventilation Flashcards
What are the 3 types of ventilation?
- Horizontal
- Vertical
- Positive pressure
Synthetic products after 1970 now cause IGNITION to FLASHOVER how much faster?
30 times!
What is the primary responsibility of the 1st due truck on a box?
Life safety
(Entry, search rescue, horizontal ventilation)
What are the 4 position names of a truck crew?
Irons
Hook
AO app operator
OV outside vent
What are the 3 operational modes of a truck crew?
All in for search
All out for ventilation
Splitting
Where should ventilation openings never be created?
Behind an advancing hose line
What is proper timing considered regarding COORDINATED ventilation?
Interior crews breathing SCBA and have a charged hose line in position, making a push or actually hitting the fire
Where is proper placement of a heat hole for vertical ventilation?
As close to directly over the fire as safely possible
Where is proper placement of a horizontal ventilation opening?
On the OPPOSITE side of the fire room from the advancing hose line
What should you not do if the location of the fire is unknown?
DO NOT break windows!!
What are the responsibilities of the second due truck?
Assist first due truck with unfinished responsibilities
Ladder upper floors for egress
What are the 3 critical radio communications made by 1st due engine specific to horizontal ventilation?
Fire attack is making entry
Location of fire
Take the glass
What is the appropriate tactic if it is believed that Backdraft conditions exist?
Vertical ventilation
What are the 3 kinds of roof holes?
Inspection hole
Smoke indicator hole
Heat hole
What size heat hole should you cut?
4x4 on residential
4x8 on commercial
Is a heat hole offensive or defensive?
Offensive
Is a trench cut offensive or defensive?
Defensive
What should the spacing be for indicator holes?
Every few yards
What is the initial width of a trench cut?
24-48”
When assigned to the roof what direction should you approach if possible?
Windward side
When a structure has a flat roof, where should you place the ladders?
On the corners
What must a roof crew establish as soon as possible?
A second means of egress
Does Portland fire use PPA attack?
No
When will Portland fire use ppv?
Only used for smoke removal after a fire has been knocked down
PPV is most effective with what size exhaust opening?
3/4 to 1-3/4 size of entrance
Does the heat of a fire increase or decrease interior room pressure?
Increase
Because today’s fires develop more rapidly, firefighters often arrive on scene when?
Just PRIOR to or DURING flashover!
Ventilation is defined as the systemic and coordinated removal of what for structure involved in fire?
the PRODUCTS OF COMBUSTION
What does “Take Glass” mean?
Used to let team know its an appropriate coordinated time to break a window
What is the Heat Release Rate?
The RATE at which HEAT (energy) is RELEASED by the burning of FUEL and OXYGEN
Also a MEASURE of the SIZE of the fire compared to the THERMAL HAZARD or EFFECTS of the fire
Increase in the HRR will increase what 2 things?
HEAT and SMOKE production
What is the difference between Venting for LIFE and Venting for EXTINGUISHMENT?
LIFE attempt to reach a known/suspected life hazard
EXTINGUISHMENT
What are the 2 keys to any type of successful ventilation opening?
- Proper placement
- Proper timing
What are 3 indicators and ways that confirm proper ventilation timing?
- Visual confirmation
- Radio communication with interior crews
- Other (Audible hose sounds, smoke turning to steam)
What is the difference between NATURAL and FORCED ventilation?
NATURAL (wind)
FORCED (Negative, Positive, Hydraulic)
What are some things to look at on the roof to tell you a good place for heat hole placement?
Building construction
Smoke conditions
Pressurized smoke between shingles
Bubbling tar
Sagging area
A heat/vent hole is generally placed how high on the roof?
At the highest point possible
Describe an OFFENSIVE and DEFENSIVE ventilation cut?
OFFENSIVE heat hole
DEFENSIVE trench cut
Should you cut a heat hole before a trench cut?
Yes if the fire has not yet naturally vented
Can you start pulling panels before the trench cut is finished?
NO. It will bring the fire too fast
When doing a trench cut, where should the indicator holes be placed?
Every few YARDS between heat hole and trench cut
Flat or arched roofs will usually require at least how many truckies?
Full 4 person crew
On PEAKED roofs, where is desired ladder placement?
In close proximity to desired hole location
Lightweight roofs can fail within how many minutes of fire impingement?
5
