Module Eight Exam Chimneys, Vents, And Flues Review
– Questions With Appropriate Answers
When selecting a gas furnace, how is its heating capacity determined?
Correct Answer - Its output rating should be no less than 95 percent of the
calculated heat loss of the structure.
What material is recommended for a vent connector on all non-condensing,
induced-draft furnace installations? Correct Answer - Type B vent pipe
Natural-draft furnaces generally have efficacy ratings of _________. Correct
Answer - 90 percent and above
Which of the following unlikely to directly affect the ability of a heating system
to vent combustion products? Correct Answer - The type of ignition
system used
When a flexible metal chimney liner is used, the __________. Correct Answer -
Liner may need to be a larger diameter than the correct size of smooth, rigid
pipe
If excess carbon monoxide is present in a building heated by a gas furnace, it is
likely a sign of _________. Correct Answer - Incomplete combustion
The National Fuel Gas Code category of vent system used with a natural draft
furnace is _________. Correct Answer - Category 1
Which type of vent material is not of double-wall construction? Correct
Answer - PVC
The removal of combustion gases by a natural draft is made possible by
__________. Correct Answer - Heating of the flue gases
Which gas furnace type produces water during normal operation? Correct
Answer - Condensing
– Questions With Appropriate Answers
When selecting a gas furnace, how is its heating capacity determined?
Correct Answer - Its output rating should be no less than 95 percent of the
calculated heat loss of the structure.
What material is recommended for a vent connector on all non-condensing,
induced-draft furnace installations? Correct Answer - Type B vent pipe
Natural-draft furnaces generally have efficacy ratings of _________. Correct
Answer - 90 percent and above
Which of the following unlikely to directly affect the ability of a heating system
to vent combustion products? Correct Answer - The type of ignition
system used
When a flexible metal chimney liner is used, the __________. Correct Answer -
Liner may need to be a larger diameter than the correct size of smooth, rigid
pipe
If excess carbon monoxide is present in a building heated by a gas furnace, it is
likely a sign of _________. Correct Answer - Incomplete combustion
The National Fuel Gas Code category of vent system used with a natural draft
furnace is _________. Correct Answer - Category 1
Which type of vent material is not of double-wall construction? Correct
Answer - PVC
The removal of combustion gases by a natural draft is made possible by
__________. Correct Answer - Heating of the flue gases
Which gas furnace type produces water during normal operation? Correct
Answer - Condensing
