NFI Exam Review Questions And Correct
Combustion Requirements (3) - CORRECT ANS✔✔Air, Fuel, Heat
Complete Combustion Produces (4) - CORRECT ANS✔✔Water vapor, carbon dioxide, heat, and n
incomplete combustion produces (3) - CORRECT ANS✔✔carbon monoxide, hydrocarbons, and oth
rate at which fuel burns is controlled by - CORRECT ANS✔✔the amount of available air
air to fuel ratio is a - CORRECT ANS✔✔critical factor in obtaining optimum fuel combustion
BTU - CORRECT ANS✔✔British Thermal Unit, The amount of energy needed to heat one pound o
wood ignites at - CORRECT ANS✔✔450-550 F
natural gas ignites at - CORRECT ANS✔✔1,150 F
propane ignites at - CORRECT ANS✔✔920-1120 F
electric spark temp - CORRECT ANS✔✔1,700 F
hot surface igniter temp - CORRECT ANS✔✔2,400 F
butane lighter temp - CORRECT ANS✔✔3,200 F
stick match temp - CORRECT ANS✔✔3,000 F
cigarette temp - CORRECT ANS✔✔500-800 F
For complete combustion: air is ______ % oxygen + _____ % nitrogen - CORRECT ANS✔✔20 : 80
for complete combustion, __(QTY)__ molecules of __(PART)___ need to be mixed with ___(QTY)_
_____(PART)____ in the presence of __(PART)__ - CORRECT ANS✔✔2 oxygen : 1 fuel : heat
When complete combustion happens __(4 things)___ are released - CORRECT ANS✔✔heat, carb
(H20), and nitrogen (N)
Carbon monoxide is dangerous because (other than senseless) - CORRECT ANS✔✔it mixes with
carrying capacity
Aldehydes - CORRECT ANS✔✔chemical compounds that have a strong pungent odor
, High heat transfer efficiency is normally associated with: (5 things) - CORRECT ANS✔✔Appliance
exterior surfaces with good heat radiating properties
Long residence time of the hot gases in the Appliance
Adequate turbulence inside the appliance to property transfer heat from the fire chamber to applian
Rapid heat transfer through the walls of the appliance
Adequate air movement (convection) outside
2 types of factory built fireplaces - CORRECT ANS✔✔radiating and circulating
Radiant design - CORRECT ANS✔✔transmits heat energy from firebox opening by direct radiation
not have grills or louvers on the face, heat moving blowers not avail.)
circulating design - CORRECT ANS✔✔adds function of heat transfer via heated air convection by c
chamber and releasing into space to be heated through grills and louvers
Built-in, high efficiency fireplaces - CORRECT ANS✔✔contain efficient combustion and convection
an insulated metal cabinet. Can be enclosed in close proximity to combustibles
Fireplace inserts and hearth stoves are - CORRECT ANS✔✔designed to improve the efficiency of
general appearance of the fireplace while improving its efficiency
Hearth appliance construction - CORRECT ANS✔✔modern solid fuel appliance designed to introdu
specific and controllable air inlets and are controlled by the user
Most controlled combustion devices are made of (metals) - CORRECT ANS✔✔cast iron or steel
Cast Iron (fireplace) - CORRECT ANS✔✔made from molds, can be decorative
Steel (fireplace) - CORRECT ANS✔✔welded joints that need no service, some use steel fireboxes
Soapstone (fireplace) - CORRECT ANS✔✔lower thermal conductivity, delivers heat slowly but reta
Conduction - CORRECT ANS✔✔direct transmission of heat from one surface of solid material to an
Convection - CORRECT ANS✔✔transfer of heat through a gas or liquid, including air, the transfer o
unequal density. Natural occurs between heavier, cooler air and lighter, warmer air
Forced convection occurs - CORRECT ANS✔✔By mechanical means, aka electric blower
Radiation - CORRECT ANS✔✔emission of waves of infrared energy, converted to heat on contact
Radiant appliances - CORRECT ANS✔✔single wall, exterior wall is firebox wall. Generally required
small numerous rooms
Convection appliances (3 things) - CORRECT ANS✔✔double wall construction, allows room air to
blower increases the amount and distance of heated air circulation
lower surface temperatures of outer wall exposed
less spacious area, may make immediate space too warm/stuffy
Combustion Requirements (3) - CORRECT ANS✔✔Air, Fuel, Heat
Complete Combustion Produces (4) - CORRECT ANS✔✔Water vapor, carbon dioxide, heat, and n
incomplete combustion produces (3) - CORRECT ANS✔✔carbon monoxide, hydrocarbons, and oth
rate at which fuel burns is controlled by - CORRECT ANS✔✔the amount of available air
air to fuel ratio is a - CORRECT ANS✔✔critical factor in obtaining optimum fuel combustion
BTU - CORRECT ANS✔✔British Thermal Unit, The amount of energy needed to heat one pound o
wood ignites at - CORRECT ANS✔✔450-550 F
natural gas ignites at - CORRECT ANS✔✔1,150 F
propane ignites at - CORRECT ANS✔✔920-1120 F
electric spark temp - CORRECT ANS✔✔1,700 F
hot surface igniter temp - CORRECT ANS✔✔2,400 F
butane lighter temp - CORRECT ANS✔✔3,200 F
stick match temp - CORRECT ANS✔✔3,000 F
cigarette temp - CORRECT ANS✔✔500-800 F
For complete combustion: air is ______ % oxygen + _____ % nitrogen - CORRECT ANS✔✔20 : 80
for complete combustion, __(QTY)__ molecules of __(PART)___ need to be mixed with ___(QTY)_
_____(PART)____ in the presence of __(PART)__ - CORRECT ANS✔✔2 oxygen : 1 fuel : heat
When complete combustion happens __(4 things)___ are released - CORRECT ANS✔✔heat, carb
(H20), and nitrogen (N)
Carbon monoxide is dangerous because (other than senseless) - CORRECT ANS✔✔it mixes with
carrying capacity
Aldehydes - CORRECT ANS✔✔chemical compounds that have a strong pungent odor
, High heat transfer efficiency is normally associated with: (5 things) - CORRECT ANS✔✔Appliance
exterior surfaces with good heat radiating properties
Long residence time of the hot gases in the Appliance
Adequate turbulence inside the appliance to property transfer heat from the fire chamber to applian
Rapid heat transfer through the walls of the appliance
Adequate air movement (convection) outside
2 types of factory built fireplaces - CORRECT ANS✔✔radiating and circulating
Radiant design - CORRECT ANS✔✔transmits heat energy from firebox opening by direct radiation
not have grills or louvers on the face, heat moving blowers not avail.)
circulating design - CORRECT ANS✔✔adds function of heat transfer via heated air convection by c
chamber and releasing into space to be heated through grills and louvers
Built-in, high efficiency fireplaces - CORRECT ANS✔✔contain efficient combustion and convection
an insulated metal cabinet. Can be enclosed in close proximity to combustibles
Fireplace inserts and hearth stoves are - CORRECT ANS✔✔designed to improve the efficiency of
general appearance of the fireplace while improving its efficiency
Hearth appliance construction - CORRECT ANS✔✔modern solid fuel appliance designed to introdu
specific and controllable air inlets and are controlled by the user
Most controlled combustion devices are made of (metals) - CORRECT ANS✔✔cast iron or steel
Cast Iron (fireplace) - CORRECT ANS✔✔made from molds, can be decorative
Steel (fireplace) - CORRECT ANS✔✔welded joints that need no service, some use steel fireboxes
Soapstone (fireplace) - CORRECT ANS✔✔lower thermal conductivity, delivers heat slowly but reta
Conduction - CORRECT ANS✔✔direct transmission of heat from one surface of solid material to an
Convection - CORRECT ANS✔✔transfer of heat through a gas or liquid, including air, the transfer o
unequal density. Natural occurs between heavier, cooler air and lighter, warmer air
Forced convection occurs - CORRECT ANS✔✔By mechanical means, aka electric blower
Radiation - CORRECT ANS✔✔emission of waves of infrared energy, converted to heat on contact
Radiant appliances - CORRECT ANS✔✔single wall, exterior wall is firebox wall. Generally required
small numerous rooms
Convection appliances (3 things) - CORRECT ANS✔✔double wall construction, allows room air to
blower increases the amount and distance of heated air circulation
lower surface temperatures of outer wall exposed
less spacious area, may make immediate space too warm/stuffy
