100% Verified Answers – A+ Graded
1. In a modern gas furnace, the component that seperates the combustion gases
from the supply air is the .
A) gas valve
B) heat exchanger
C) inducer fan
D) plenum box: B) heat exchanger
2. What type of furnace moves warm air through the conditioned space with-out a
fan?
A) Gravity
B) Horiẓontal
C) Lowboy
D) Upflow: A) Gravity
3. Furnace heat exchangers generally are made of .
A) ceramic
B) copper
C) plastic
D) steel: D) steel
4. What does AFUE stand for?
A) Actual Fuel Usage Efficiency
B) Annual Fuel Utiliẓation Efficiency
C) Annual Furnace Usage Equivalency
D) Approved Fuel Usage Estimate: B) Annual Fuel Utiliẓation Eflciency
5. The main purpose of a secondary heat exchanger is to .
A) evaporate the flue gases
,B) provide a backup containment
C) remove additional heat from the flue gases
D) reverse the primary air flow: C) remove additional heat from the flue gases
6. Which gas commonly used as a fuel in gas furnaces is heavier than air?
A) Butane
B) Isobutane
C) Methane
D) Propane: D) Propane
,7. Which grade of fuel oil is most commonly used in residential furnaces?
A) 1
B) 2
C) 3
D) 4: B) 2
8. How many cubic feet of air are needed to burn 1 ft^3 of natural gas?
A) 6 ft^3
B) 10 ft^3
C) 18 ft^3
D) 24 ft^3: B) 10 ft^3
9. How many cubic feet of air are needed to burn 1 ft^3 of propane?
A) 6 ft^3
B) 10 ft^3
C) 18 ft^^3
D) 24 ft^3: D) 24 ft^3
10. What is the approximate heat content of 1 ft^3 of natural gas?
A) 500 Btu
B) 800 Btu
C) 1,050 Btu
D) 2,500 Btu: C) 1,050 Btu
11. What is the approximate heat content of 1 ft^3 of propane?
A) 500 Btu
B) 800 Btu
C) 1,050 Btu
D) 2,500 Btu: D) 2,500 Btu
12. What is the approximate heat content of one gallon of No. 2 fuel oil?
A) 75,000 to 90,000 Btu
B) 95,000 to 135,000 Btu
C) 137,000 to 142,000 Btu
, D) 145,000 to 170,000 Btu: C) 137,000 to 142,000 Btu
13. What is a typical manifold pressure for a natural gas furnace?
A) 3.5 in. w.c.