CCP CCP Chimney Draft & Combustion Principles 2 — Questions and Answers
Question 1: What are the three elements of the fire triangle required for combustion?
- Fuel, oxygen, and heat (Correct answer)
- Fuel, nitrogen, and spark
- Carbon, hydrogen, and oxygen
- Wood, coal, and gas
Correct answer: Fuel, oxygen, and heat
Combustion requires fuel, oxygen, and heat — the three sides of the fire triangle — and all three must be present simultaneously.
Question 2: What are the primary byproducts of complete combustion of a carbon-based fuel?
- Carbon dioxide and water vapor (Correct answer)
- Carbon monoxide and soot
- Nitrogen dioxide and ash
- Sulfur dioxide and creosote
Correct answer: Carbon dioxide and water vapor
Complete combustion of carbon-based fuels produces carbon dioxide (CO₂) and water vapor (H₂O) as the primary byproducts.
Question 3: What combustion byproduct is most dangerous because it is odorless and colorless?
- Carbon monoxide (CO) (Correct answer)
- Carbon dioxide (CO₂)
- Nitrogen oxide (NOₓ)
- Water vapor (H₂O)
Correct answer: Carbon monoxide (CO)
Carbon monoxide is the most dangerous combustion byproduct because it is odorless, colorless, and can cause fatal poisoning without any sensory warning.
Question 4: What most commonly causes incomplete combustion in a wood-burning fireplace?
- Insufficient air supply (Correct answer)
- Too much draft
- Oversized firebox
- Dry seasoned wood
Correct answer: Insufficient air supply
Insufficient air supply leads to incomplete combustion, producing carbon monoxide, creosote, and smoke instead of fully oxidized flue gases.
Question 5: What flue gas temperature range indicates efficient combustion in a wood stove?
- 300°F to 700°F (149°C to 371°C) (Correct answer)
- 100°F to 200°F (38°C to 93°C)
- 900°F to 1,200°F (482°C to 649°C)
- 1,500°F to 2,000°F (816°C to 1,093°C)
Correct answer: 300°F to 700°F (149°C to 371°C)
Optimal wood stove flue gas temperatures of 300°F to 700°F indicate efficient combustion while avoiding excessive creosote formation from too-cool gases.
Question 6: Which type of combustion produces the most creosote in a chimney?
- Slow, smoldering combustion with restricted air (Correct answer)
- Hot, fast combustion with ample air
- Short, intense fires with dry wood
- High-temperature burns with seasoned hardwood
Correct answer: Slow, smoldering combustion with restricted air
Slow, smoldering fires with restricted air supply produce the most creosote because unburned hydrocarbons condense on the cooler flue walls.
CCP CCP Chimney Draft & Combustion Principles 2
What are the three elements of the fire triangle required for combustion?