Chapter 14

Question 1

Phenomenom of a strong air draft moving from the ground level to roof level of a building.

Affected by outside temp vs. inside temp.

Can also work in reverse.

p. 412

Answer 1

Stack Effect

Question 2

Tendency of smoke to rise until it encounters a horizontal obstruction then bank down.

p. 413

Answer 2

Mushrooming

Question 3

Formation of layers of smoke as a result of the loss of density from cooling. Can cause smoke to spread laterally or downward.

p. 413

Answer 3

Stratification

Question 4

PPV blowers positioned at street level are effective up to how many floor?

p. 414

Answer 4

22 Floors

Question 5

Assuming the structure is closed, with little or no gas being vented to the atmosphere, a neutral pressure plane exists at the level of ambient atmospheric temperature.

At what height does this usually occur?

p. 419

Answer 5

35-50% of building height

“1/3 to 1/2” the building height

Question 6

HVAC system dampers should shut down the system when duct ________ detectors are activated.

p. 424

Answer 6

Smoke Detectors

Question 7

These vents are intended to limit the spread of fire by vertically venting before the mushroom effect can occur. Although some are now activated by smoke detectors, most are still activated by fusible links.

p. 425

Answer 7

Automatic Roof Vents

Question 8

Curtain boards or draft curtains protrude down from the underside of a roof/ceiling. They generally extend equal to at least _____% of the vertical height from the floor to ceiling.

But not more than ____ feet above the floor.

p. 427

Answer 8

20%

10 feet