16 - Ventilation

Question 1

Define Ventilation (Verbatim)

Answer 1

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.

Question 2

Define thermal layering

Answer 2

Thermal layering is the layering of heated gases according to temperature – the
hottest gases tend to be on the top layer

Question 3

Backdraft / Flashover

Answer 3

Backdraft / Flashover or the potential for either can be substantially reduced when a coordinated and placed ventilation system is used, allowing gases to safely escape.

Question 4

What is black fire

Answer 4

the term we give to high
volume, high velocity, and extremely dense,
black smoke. It is a sure indicator of an impending flashover. Treat black fire just as
actual flames.

Question 5

Stack Effect factors

Answer 5

How tightly sealed the building is
Distacne between upper and lower openings
Difference between outside and inside temps

Question 6

Natural stack effect

Answer 6

Hotter inside air
Cooler outside air
Smoke/gases evacuate up

Question 7

Reverse Stack

Answer 7

Cooler inside air
Hotter outside air
Smoke banks down to lobby

Question 8

Problems with high-rise ventikation

Answer 8

Increased occupancy that is exposed to heat, smoke and fire gases

Fixed windows may alter the most efficient ventilation flow path.

Increased logistical issues – greater amount of door control, required
manpower and equipment for effective ventilation.

More time is required to establish ventilation due to the size of the
structure.