NFI Exam Questions with Right Answers
Combustion requires? - ✅✅ Air, Fuel, Heat
Complete combustion produces? - ✅✅ Water vapor, carbon dioxide, heat, and
non combustible ashes
Incomplete combustion produces? - ✅✅ carbon monoxide, hydrocarbons, and
other gases
The rate at which fuel burns is controlled by? - ✅✅ the amount of available air
Air to fuel ratio is a? - ✅✅ critical factor in obtaining optimum fuel combustion
Flashing - ✅✅ seal roof cutout from water entry
Stabilizes chimney, different angles for different pitching
Flange attached to roof under roofing material at high end, lapped over on sides
and sealed
Chimney Chase - ✅✅ Conceals chimney
,Interior location best
Insulate (secure to avoid sagging or contact with chimney, no blown insulation
unless covered wall cavity, and seal gaps around framing)
Fire stops may be required at all floor/ceiling levels
Chase cut through eaves should not be open to attic
Cricket - ✅✅ if chase more than 30" wide measured perpendicular to roof slope
Sheet metal or same material as roof
Firestop Spacers - ✅✅ blocking to prevent fire spread
Correct spacing to meet clearances
Provides lateral side to side support
Decorative Shroud - ✅✅ covers chase and replaces listed termination capt,
mostly prohibited
Thimbles - ✅✅ noncombustible, round fire clay liner/thimble, not less than 5/8"
thick
Cemented into masonry wall opening with refractory mortar, thimble extends to
but not past flue wall
,Single Wall Connector - ✅✅ materials - NFPA 211 prohibits use of galvanized
steel pipe, requires 24 gauge or more
Size and length - at least appliance flue collar size
Double Wall Connector - ✅✅ listed for close clearances
May be required for use with the factory built chimney
May be recommended to reduce heat loss problems of longer single wall
connectors
BTU - ✅✅ British Thermal Unit, The amount of energy needed to heat one
pound of water one degree Fahrenheit
Wood ignites at - ✅✅ 450-550 ℉
Natural gas ignites at - ✅✅ 1,150 ℉
Propane ignites at - ✅✅ 920-1120 ℉
Electric spark temp - ✅✅ 1,700 ℉
Hot surface igniter temp - ✅✅ 2,400 ℉
, Butane lighter temp - ✅✅ 3,200 ℉
Stick match temp - ✅✅ 3,000 ℉
Cigarette temp - ✅✅ 500-800 ℉
For complete combustion: air is ______ % oxygen + _____ % nitrogen - ✅✅
20 : 80
For complete combustion, __(QTY)__ molecules of __(PART)___ need to be
mixed with ___(QTY)__ molecule of _____(PART)____ in the presence of
__(PART)__ - ✅✅ 2 oxygen : 1 fuel : heat
When complete combustion happens __(4 things)___ are released - ✅✅ heat,
carbon dioxide (C02), water vapor (H20), and nitrogen (N)
Carbon monoxide is dangerous because (other than senseless) - ✅✅ it mixes
with blood and reduces oxygen carrying capacity
Aldehydes - ✅✅ chemical compounds that have a strong pungent odor
Carbon monoxide is ________ when aldehydes are present - ✅✅ present
Aldehydes result from - ✅✅ flame impingement and through the presence of
contaminated air
Combustion requires? - ✅✅ Air, Fuel, Heat
Complete combustion produces? - ✅✅ Water vapor, carbon dioxide, heat, and
non combustible ashes
Incomplete combustion produces? - ✅✅ carbon monoxide, hydrocarbons, and
other gases
The rate at which fuel burns is controlled by? - ✅✅ the amount of available air
Air to fuel ratio is a? - ✅✅ critical factor in obtaining optimum fuel combustion
Flashing - ✅✅ seal roof cutout from water entry
Stabilizes chimney, different angles for different pitching
Flange attached to roof under roofing material at high end, lapped over on sides
and sealed
Chimney Chase - ✅✅ Conceals chimney
,Interior location best
Insulate (secure to avoid sagging or contact with chimney, no blown insulation
unless covered wall cavity, and seal gaps around framing)
Fire stops may be required at all floor/ceiling levels
Chase cut through eaves should not be open to attic
Cricket - ✅✅ if chase more than 30" wide measured perpendicular to roof slope
Sheet metal or same material as roof
Firestop Spacers - ✅✅ blocking to prevent fire spread
Correct spacing to meet clearances
Provides lateral side to side support
Decorative Shroud - ✅✅ covers chase and replaces listed termination capt,
mostly prohibited
Thimbles - ✅✅ noncombustible, round fire clay liner/thimble, not less than 5/8"
thick
Cemented into masonry wall opening with refractory mortar, thimble extends to
but not past flue wall
,Single Wall Connector - ✅✅ materials - NFPA 211 prohibits use of galvanized
steel pipe, requires 24 gauge or more
Size and length - at least appliance flue collar size
Double Wall Connector - ✅✅ listed for close clearances
May be required for use with the factory built chimney
May be recommended to reduce heat loss problems of longer single wall
connectors
BTU - ✅✅ British Thermal Unit, The amount of energy needed to heat one
pound of water one degree Fahrenheit
Wood ignites at - ✅✅ 450-550 ℉
Natural gas ignites at - ✅✅ 1,150 ℉
Propane ignites at - ✅✅ 920-1120 ℉
Electric spark temp - ✅✅ 1,700 ℉
Hot surface igniter temp - ✅✅ 2,400 ℉
, Butane lighter temp - ✅✅ 3,200 ℉
Stick match temp - ✅✅ 3,000 ℉
Cigarette temp - ✅✅ 500-800 ℉
For complete combustion: air is ______ % oxygen + _____ % nitrogen - ✅✅
20 : 80
For complete combustion, __(QTY)__ molecules of __(PART)___ need to be
mixed with ___(QTY)__ molecule of _____(PART)____ in the presence of
__(PART)__ - ✅✅ 2 oxygen : 1 fuel : heat
When complete combustion happens __(4 things)___ are released - ✅✅ heat,
carbon dioxide (C02), water vapor (H20), and nitrogen (N)
Carbon monoxide is dangerous because (other than senseless) - ✅✅ it mixes
with blood and reduces oxygen carrying capacity
Aldehydes - ✅✅ chemical compounds that have a strong pungent odor
Carbon monoxide is ________ when aldehydes are present - ✅✅ present
Aldehydes result from - ✅✅ flame impingement and through the presence of
contaminated air
