NFI Exam Review Questions with

NFI Exam Review Questions with Complete Solutions (Latest 2025) Combustion Requirements (3) - Correct Answers ✅Air, Fuel, Heat Complete Combustion Produces (4) - Correct Answers ✅Water vapor, carbon dioxide, heat, and non combustible ashes incomplete combustion produces (3) - Correct Answers ✅carbon monoxide, hydrocarbons, and other gases rate at which fuel burns is controlled by - Correct Answers ✅the amount of available air air to fuel ratio is a - Correct Answers ✅critical factor in obtaining optimum fuel combustion BTU - Correct Answers ✅British Thermal Unit, The amount of energy needed to heat one pound of water one degree Fahrenheit wood ignites at - Correct Answers ✅450-550 F natural gas ignites at - Correct Answers ✅1,150 F propane ignites at - Correct Answers ✅920-1120 F 1 / 4

NFI Exam Review Questions with Complete Solutions (Latest 2025) electric spark temp - Correct Answers ✅1,700 F hot surface igniter temp - Correct Answers ✅2,400 F butane lighter temp - Correct Answers ✅3,200 F stick match temp - Correct Answers ✅3,000 F cigarette temp - Correct Answers ✅500-800 F

For complete combustion: air is ______ % oxygen + _____ %

nitrogen - Correct Answers ✅20 : 80

for complete combustion, __(QTY)__ molecules of __(PART)___ need to be mixed with ___(QTY)__ molecule of _____(PART)____ in the presence of __(PART)__ - Correct Answers ✅2 oxygen : 1 fuel : heat When complete combustion happens __(4 things)___ are released - Correct Answers ✅heat, carbon dioxide (C02), water vapor (H20), and nitrogen (N) 2 / 4

NFI Exam Review Questions with Complete Solutions (Latest 2025) Carbon monoxide is dangerous because (other than senseless) - Correct Answers ✅it mixes with blood and reduces oxygen carrying capacity Aldehydes - Correct Answers ✅chemical compounds that have a strong pungent odor Carbon monoxide is ________ when aldehydes are present - Correct Answers ✅present Aldehydes result from - Correct Answers ✅flame impingement and through the presence of contaminated air Efficiency formula - Correct Answers ✅Heat output divided by heat input (percentage of heat transferred to room)

• Ts of efficiency - Correct Answers ✅Temperature,

turbulence, time Temperature (efficiency) - Correct Answers ✅minimum ignition temp Turbulence (efficiency) - Correct Answers ✅fuel must collide with oxygen molecules (refers to the degree of fuel and air mixing that occurs in combustion zone) 3 / 4

NFI Exam Review Questions with Complete Solutions (Latest 2025) Time (efficiency) - Correct Answers ✅amount of time fuel gases remain in the high temp zone. also known as "residence time" Heat Transfer Efficiency - Correct Answers ✅refers to the percentage of heat generated by combustion actually transferred to room

High heat transfer efficiency is normally associated with: (5

things) - Correct Answers ✅Appliance having proportionally large 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 appliance walls Rapid heat transfer through the walls of the appliance Adequate air movement (convection) outside

• types of factory built fireplaces - Correct Answers

✅radiating and circulating

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