Chapter 7: Combustion Air

Question 1

When using the Standard Method, what is the minimum required volume of indoor combustion air?

Answer 1

50 cubic feet per 1,000 Btu/hr.

Question 2

Combining spaces in different stories, the openings in doors and floors shall have a total minimum free area of _________ square inch(es) per 1,000 Btu/hr.

Answer 2

2 square inches (with a minimum opening size of 100 square inches)

Question 3

Outdoor combustion air openings shall have a minimum or _______ inch(es).

Answer 3

3 inches

Question 4

Two combustion air openings communicating directly to the outdoors shall commence within _______ inches of the top and ______ inches of the bottom of the enclosure.

Answer 4

12 inches, 12 inches

Question 5

The One Permanent Opening Method requires that equipment shall have a minimum clearence of _____ inch(es) from the front of the appliance.

Answer 5

6 inches

Question 6

Appliances located in a confined space with air taken from the outside of the structure by means of one vertcal or horizontal duct shall have a minimum free area of 1 square inch per _________ Btu/hr.

Answer 6

3,000

Question 7

Engineered combustion air instillations shall provide adequate supply of combustion, ventillation, and silution air and shall be approved by the ______.

Answer 7

Authority Having Jurisdiction

Question 8

Where all cumbustion air is provided by a mechanical air supply syatem, the combustion air shell be supplied fro outdoors at a minimum rate of __________ cubic feet per 1000 Btu/hr.

Answer 8

0.35 Cubic feet

Question 9

Where exhaust fans are installed, additional air shall be provided to replace the __________ air.

Answer 9

Exhausted

Question 10

Where the design and free area are not known, it shall be assumed that wood louveres will have ________ free space.

Answer 10

25%

Question 11

Where the design and free area are not known, it shall be assumed that metal louvers will have _________ percent free area.

Answer 11

75%

Question 12

_________ louvers shall be interlocked with the equipment so they are proven in the full open position prior to main burner ignition and during main burner operation.

Answer 12

Motorized

Question 13

Combustion air ducts shall serve a ________ space.

Answer 13

Single

Question 14

Intakes for combustion air ducts located exterior to the building shall have the lowest side of the combustion air intake at least _________.

Answer 14

12

Question 15

________ operated dampers shall not be installed in combustion air openings.

Answer 15

Manually

Question 16

Horizontal combustion air ducts shall not slope ________ toward the source of combustion air.

Answer 16

Downward

Question 17

The remaining space surrounding a chimney liner, gas vent, special gas vent, or plastic piping installed within a masonry, metal or factory-built chimney shall not be used to supply combustion air unless it is ___________ in the manufacturer’s instillation instructions.

Answer 17

Listed and shown

Question 18

The Known Air Infiltration Rate Method requires (15ft3/ACH) x (Ifan/1,000 Btu/h) for fan assisted appliances, but no smaller than _________ cubic feet per 1,000 Btu/hr.

Answer 18

25 Cubic feet

Question 19

The One Permanent Opening Method requires the equipment have a clearance of at least _________ inch(es) from the side and back.

Answer 19

1 Inch

Question 20

Combustion air is not required for _________.

Answer 20

Domestic clothes dryers

Question 21

Combustion air ducts, except in dwellings, shall be made of _____________.

Answer 21

Galvanized steel

Question 22

When determining combustion air requirements, operation of exhaust fans, kitchen ventilating systems, clothes dryers, and fireplaces shall have ___________.

Answer 22

Makeup air provided

Question 23

Combustion air ducts that terminate in an attic shall be screened ____________.

Answer 23

At neither end

Question 24

Power-actuated movable louvers admitting combustion air may be used __________.

Answer 24

With prior approval

Question 25

Appliances located in a combined space with all air taken from the outside of the building and from the same story shall have each opening for combustion air sized at 1 square inch per ___________ Btu/hr.

Answer 25

1,000 Btu/hr. (minimum 100 square inches)

Question 26

Appliances located in a confined space with all air taken from the outside by means of two horizontal ducts shall have each opening size based on 1 square inch per ________ Btu/hr.

Answer 26

2,000 Btu/hr.

Question 27

Dampers in combustion air ducts or plenums are _____________>

Answer 27

Prohibited

Question 28

The required size of combustion air openings shall be ____________.

Answer 28

Based on the net free area of each opening