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Flashcards in Ch. 9 Ventilation Deck (67)
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Two main reasons for performing ventilation

Venting for fire
Venting for life


4 problems with thinking ventilation isn't as important because of SCBA's

Ignores victims inside
Assumes FF's mask will always protect
Buildup of heat
Buildings are made tighter (backdraft)


Distinguishing between Vent for Life and Vent for Fire, KEY FACTOR IS:

Timing of ventilation
Life = as soon as possible
Fire = delayed until resources in place to attack


Most important concept when discussing ventilation:

Must be of sufficient volume to WIN!


Break window vs opening

Can stand up, open
Window stuck and not lot of heat/smoke, find another means
Driven back by heat, break WHEN HOSELINE IS CHARGED


Difficulties with double glazed Windows

Can't blow out with hoseline
Inability to clear horizontal sash (more dangerous)


After placement of attack and interior search, this is most crucial: (Chapter 9, Vent)

Outside Vent team


Horizontal vent faster and easier to perform than vertical?

Takes advantage of existing openings


Venting using fog: several factors determine how much air and smoke moved (3)

Velocity = pattern + pressure. 30 degree range of fog
Geometry of opening (6-8 ft back)


Fans not covering opening correctly (exhaust devices - sucking smoke)

Churning - pulls air from outside, to inside and back out - LIMITS EFFICIENCY


2 most common vertical arteries/avenues

Pipe chase


2 types of old-style roofs

Standard flat roof: roof joist at roof level, roof boards nailed to joists
Inverted roof: roof boards nailed to framework of 2x4's several feet above main roof joists


Style of roof that has been dominant in the flat roof industry in the last 20 years, at least in the East and Midwest:

Metal deck roof


Dimensions for flat roofs (standard flat roof)

2 x 10's or 3 x 12's beams
16 in apart (carry same load as floors)
Limited to 20 ft span between supports, masonry wall or steel I-beam
Decking is 1 x 6's


Characteristics of older flat roof (old-style)

20-30 years lifespan
3-4 in of tar paper
VERY substantial roof
Relatively safe to work (even over heavy body of fire)
Catastrophic roof failure NOT A CONCERN


Working fire on top floor of any large-area flat-roof requires:

At least 4 members with:
2 power saws, (2) 6 or 8 ft hooks (10 ft for large bldg, cockloft may be 5 ft), halligan, axe, portable radio-preferably officer experienced in ventilation


2 things done immediately upon reaching the roof:

Vent any vertical shafts (bulkhead doors or skylights)
Simultaneously, member can lean over parapet and vent top-floor windows in the fire area with hook or halligan tool clipped to short rope


Simplest, fastest examination hole: 1/4 in. by 10 in.



Size of triangular opening for inspection

8-10 in triangle


First concern after choosing the proper site for venting roof:

Means of escape
Always have 2 ways off the roof


Second concern after choosing proper site for venting roof:

Wind direction-may be first if wind blows smoke/fire and cuts off retreat


When sounding roof, striking with an axe and tool has slight bounce means:

In between joists


Cut close to inside of joists: (2 reasons)

Large an opening as possible
Fewer nails to pull against


Roof hole subdivided into what size:

4 ft x 4 ft max


A spongy feel on an inverted roof means:

Normal for inverted roof
NOT a sign of impending failure


Spacing on uprights - inverted roof

Post 2 ft on center
Rows 4 ft on center
(P2R4 alphabetical)


Dangers of rain roof (3)

Added weight
Delay or prevent ventilation
Multiple voids


Insulspan is made of ______ and dimensions are ______.

Styrofoam sandwiched between OSB.
8 ft widths, up to 24 ft lengths


Insulspan difficulties (2)

Styrofoam = highly combustible and toxic smoke/intense flame
As much as 8 1/2 in. thick, circular 4 in. cut, chain saw 9 in. but chain guard doesn't readily allow deep cut


H-typed bldgs or H or E or O shaped
Primary factor in all of these is:
Fairly narrow connecting section called:

Common cockloft