#1
Which of the following is a primary function of a heating system?
Providing warmth to the indoor environment
ExplanationHeating systems primarily provide warmth indoors.
#2
What is the typical fuel source used in combustion furnaces?
Natural gas
ExplanationCombustion furnaces commonly use natural gas as a fuel source.
#3
Which component of a furnace is responsible for igniting the fuel-air mixture?
Pilot light or igniter
ExplanationThe pilot light or igniter ignites the fuel-air mixture in a furnace.
#4
What does AFUE stand for in the context of heating systems?
Annual Fuel Utilization Efficiency
ExplanationAFUE stands for Annual Fuel Utilization Efficiency, a measure of heating system efficiency.
#5
What is the purpose of a heat exchanger in a furnace?
To transfer heat from the combustion process to the air
ExplanationHeat exchangers transfer heat from combustion to air in furnaces.
#6
What is the primary function of a flue in a combustion furnace?
To remove combustion byproducts
ExplanationThe flue's primary function is to remove combustion byproducts from a furnace.
#7
What does the term 'stack effect' refer to in the context of heating systems?
The movement of air through a building due to temperature differences
ExplanationStack effect refers to air movement in buildings caused by temperature differences.
#8
Which of the following is NOT a common type of furnace ignition system?
Thermostat ignition
ExplanationThermostat ignition is not a common type of furnace ignition system.
#9
What role does a flame sensor play in the operation of a furnace?
Detecting the presence of a flame
ExplanationFlame sensors detect the presence of a flame in furnace operation.
#10
Which factor primarily affects the efficiency of a combustion furnace?
Combustion air-to-fuel ratio
ExplanationThe combustion air-to-fuel ratio is a primary factor influencing combustion furnace efficiency.
#11
Which type of furnace operates with the highest efficiency?
Modulating furnace
ExplanationModulating furnaces operate with the highest efficiency.
#12
What is the main advantage of a modulating furnace over a single-stage furnace?
Increased energy efficiency
ExplanationModulating furnaces offer increased energy efficiency compared to single-stage furnaces.
#13
Which factor can negatively impact the efficiency of a furnace over time?
Accumulation of soot and debris in the heat exchanger
ExplanationAccumulation of soot and debris in the heat exchanger can reduce furnace efficiency over time.
#14
Which of the following is a potential consequence of inefficient combustion in a furnace?
Reduced indoor air quality
ExplanationInefficient combustion in furnaces can lead to reduced indoor air quality.
#15
What is the purpose of a draft inducer in a furnace?
To create proper airflow for combustion
ExplanationDraft inducers ensure proper airflow for combustion in furnaces.
#16
What is the purpose of a secondary heat exchanger in a high-efficiency furnace?
To extract additional heat from combustion gases
ExplanationSecondary heat exchangers extract additional heat from combustion gases in high-efficiency furnaces.