Chapter 6: Duct systems

Question 1

Return air ducts, outside air ducts, plenums, or concealed spaces may be of combustible construction when _______.

Answer 1

serving a dwelling unit

Question 2

Joints of duct systems shall be made substantially tight by means of ______.

Answer 2

tape, mastic, or gasketing

Question 3

The minimum distance from the ground to any metal duct shall not be less than _______ inches.

Answer 3

4 inches

Question 4

Insulation applied to the surface of ducts, including duct coverings, linings, tapes, and adhesives, located in a building shall have a flame-spread index not greater than ________.

Answer 4

25

Question 5

The smoke-developed rating of insulation applied to surface of ducts, including duct coverings, linings, tapes and adhesives, located in a building shall be of not more than ___________.

Answer 5

50

Question 6

Crimo joints for round ducts shall have a contact lap of at least ________ inch(es).

Answer 6

1 1/2 inches

Question 7

Electrical wiring in plenums shall comply with ________ and the National Electric Code.

Answer 7

NFPA 70

Question 8

The temperature of air conveyed in approved factory-mace air ducts is limited to _________ degrees Farhenheit.

Answer 8

250 degrees

Question 9

Horizontal 10 inch diameter round duct shall be supported ot intervals of not more than _________ feet.

Answer 9

10 feet

Question 10

Vertical ducts with a diameter of 10 inches shall be supported at intervals not more than ________.

Answer 10

12 feet on centers

Question 11

Air-moving systems supplyig air in excess of 2,000 cfm shall be equiped with ________.

Answer 11

An auto shut off

Question 12

What information shall be legibly printed on factory-made air ducts and faced insulation?

Answer 12

Thermal resistance (R) value at installed thickness

Question 13

Automatic shut off is not required___________.

Answer 13

When rooms have direct exit to the building exterior and the travel distance is less than 100 feet

Question 14

When smoke detectors are required as part of an automatic shutoff system, they shall be installed in the _______.

Answer 14

Main supply air duct served by such equioment

Question 15

Where gypsum products are exposed in ducts or plenums, the air temperature shall be restricted to a range from ___________ degrees Fahrenheit.

Answer 15

50 to 125 degrees

Question 16

Exhaust ducts under positive pressure and venting systems shall not extend into or through _________.

Answer 16

Ducts or plenums

Question 17

Ducts exposed to mechanical damage by vehicles or from other causes shall be ___________.

Answer 17

protected by approved barriers

Question 18

The minimum dimensions for access openings for fire dampers shall be_____________________.

Answer 18

Adequate to permit inspetion and maintenance of the damper and its oprating parts

Question 19

The use of rated corridors in fire-resistive construction to convey air yo or from adjoining rooms is _________.

Answer 19

Prohibited by this code

Question 20

Each access door for a smoke damper or fire damper shall be labeled with letters not less than ________ inch(es) high.

Answer 20

1/2 inch

Question 21

What type of duct material is not approved for heating, cooling, or evaporative-cooling?

Answer 21

Flexible connectors