CH 14

Question 1

Fire behavior in high-rise buildings is most affected by

Answer 1

stack effect and mushrooming
pg 412

Question 2

________ is the natural vertical movement of heat and smoke (convection) in tall structures.

Answer 2

stack effect
pg 412

Question 3

The greater the difference between the inside and outside temperature and the greater the building height, the greater the _________ will be.

Answer 3

stack effect
pg 412

Question 4

If it is hotter inside than outside, the airflow will be _____ at the bottom and _______ at the top. But if the outside air is hotter than the air inside, the flow will be reversed. This is known as

Answer 4

inward; outward; reverse stack effect
pg 412

Question 5

Once _____ occurs, the smoke spreads laterally and downward until the building is either completely filled or it is ventilated.

Answer 5

stratification
pg 413

Question 6

Most PPV blowers positioned at the street level are effective up to about ____ floors.

Answer 6

22
pg 414

Question 7

Top ventilation can prevent or reduce mushrooming on the upper floors and does not promote _______, which is always a danger when horizontally venting multistory buildings below the floor.

Answer 7

lapping
pg 415

Question 8

In a closed compartment, the point where the interior pressure is equal to the pressure outside the space is called the

Answer 8

neutral pressure plane
pg 418

Question 9

Assuming that the structure is closed, with little or no gases being vented to the atmosphere, a neutral pressure plane exists at the level of ambient atmospheric pressure (usually between _________% of the building height).

Answer 9

35 to 50%
pg 419

Question 10

______________ are intended to limit the spread of fire within a building by releasing heat and smoke to the outside before the fire mushrooms throughout the building.

Answer 10

automatic roof vents
pg 425

Question 11

_____________, also known as draft curtains, are fire-resistive half-walls that extend down from the underside of the roof. They generally extend a distance equal to at least ____% of the vertical distance from the floor to the roof but not lower than ___ foot above the floor.

Answer 11

curtain boards; 20, 10
pg 427

Question 12

The function of ________ is to limit the horizontal spread of heat and smoke by confining it to a relatively small area directly above its source.

Answer 12

curtain boards
pg 427

Question 13

Usually, but not always, _________ have no windows and ________ have small windows between grade level and the building first floor of the building.

Answer 13

cellars, basements
pg 428