Ch. 6 Ventilation

Question 1

Elevators that service all floors of a building

Answer 1

Service elevator

Question 2

Elevators may service only selected floors of a building

Answer 2

Banked elevators

Question 3

Stairshafts in high rise buildings constructed aster 1974 are required to employ a

Answer 3

Stairshaft ventilation system

Question 4

Pressurization fans must provide not less than ___ cubic feet per minute while maintaining a positive pressure of not over ___ lbs on interior doors

Answer 4

50 cubic feet
25 lbs

Question 5

HVAC systems can be operated by what two systems

Answer 5

1. Manual
2. Automatic

Question 6

The formation of stratified smoke and fire gases on floors below the top of a multi-story building is enhanced in high-rise buildings due to their height and open vertical passageways (such as stairshafts).
Stratification of smoke and fire gases occurs as heat and smoke travel vertically within a building. These products of combustion will rise through any available vertical opening, cooling as they rise, until the temperature is equal to the temperature of the surrounding air. When stabilization of the temperature occurs, smoke and fire gases will form layers or clouds within the building (Figure No. 1). This stratification of smoke and fire gases generally serve as a “lid” for other products of combustion which will tend to bank down below the stratified smoke and horizontally spread to other portions of the building. This process is common in vertical stairshafts.
Mushrooming is a condition caused by smoke and fire gases that cannot vertically escape a building. Smoke and fire gases will rise to the highest level possible and then begin to bank down and fill all available spaces (Figure No. 2). Mushrooming smoke and fire gases

can contaminate the upper floors, or contaminate the floors below stratified smoke in the stairshaft. Smoke may bank down below the fire floor. In stairshafts, this may occur all the way down to the entrance level

Answer 6

Reference

Question 7

What type of windows in Pre 1960

Answer 7

Openable

Question 8

What type of windows Post 1960

Answer 8

Tempered glass on at least two sides of the building

Question 9

What type of windows post 1974

Answer 9

Tempered glass on four sides of the building

Question 10

How are tempered glass windows identified in High Rise

Answer 10

3” luminous or reflective decals, lower corner “For Fire Department Use”

Question 11

Post 1996, what was required in High Rise which eliminated the requirements of tempered glass

Answer 11

Smoke Control Systems (uniform building Code)

Question 12

What are the two categories of stairshafts

Answer 12

1. Open to the interior only of a building and provide roof access
2. Stairshafts that open to the exterior of a building and provide roof access

Question 13

Natural air flow within building stairshafts is virtually static in buildings up to __ stories

Answer 13

25

Question 14

Natural vertical air currents of ___ to ___ mph, that flow upward in stairshafts, can be created by simply opening a door at the bottom and roof levels of a stairshaft

Answer 14

Three to six

Question 15

Natural vertical air flow in a stairshaft can be created or maintained by

Answer 15

1. Stairshaft Pressurization Fans
2. Positive Pressure

Question 16

High Rise buildings post 1974 are required to employ an emergency smoke control system that has:

Answer 16

1. Pressurized stairshaft
2. Mechanical smoke removal system
3. Tempered glass or openable windows

Question 17

Regardless of size; portable blowers should be placed how for back from doorway and angled how many degrees

Answer 17

4 to 6 feet
5 degrees

Question 18

Placing fans in what shape is more effective then placing them in series

Answer 18

V-shape