Indiana Hvac Contractor Practice Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which organization publishes the International Mechanical Code
(IMC)?
A. ASHRAE
B. International Code Council (ICC)
C. NFPA
D. EPA
The IMC is developed and maintained by the International Code
Council, which also publishes the IBC and IPC.
2. What is the primary purpose of a heat exchanger in a furnace?
A. Circulate combustion air
B. Remove exhaust gases
C. Transfer heat from combustion gases to supply air
D. Regulate gas pressure
The heat exchanger safely transfers heat to the air stream without
mixing combustion gases with indoor air.
3. Which refrigerant property allows heat to be absorbed during
evaporation?
A. Density
B. Pressure
C. Latent heat
D. Viscosity
Latent heat enables a refrigerant to absorb large amounts of heat as
it changes from liquid to vapor.
,4. What device meters refrigerant into the evaporator in a TXV system?
A. Compressor
B. Receiver
C. Thermostatic expansion valve
D. Accumulator
A TXV regulates refrigerant flow based on superheat to protect the
compressor.
5. Which electrical device protects a motor from overload conditions?
A. Fuse
B. Circuit breaker
C. Thermal overload relay
D. Transformer
Thermal overloads respond to excess current over time, preventing
motor overheating.
6. What is the minimum clearance typically required around a gas
furnace for service access?
A. 6 inches
B. 12 inches
C. 30 inches
D. 48 inches
Mechanical codes generally require about 30 inches of working
clearance for service and inspection.
7. Which duct material is most commonly used in residential HVAC
systems?
A. Copper
B. PVC
C. Galvanized steel
D. Cast iron
Galvanized steel is durable, fire-resistant, and widely accepted by
code.
8. What instrument is used to measure airflow in ducts?
A. Manometer
B. Thermometer
C. Anemometer
D. Hygrometer
, An anemometer measures air velocity, which can be used to
calculate airflow.
9. Which component prevents liquid refrigerant from entering the
compressor?
A. Receiver
B. Filter-drier
C. Accumulator
D. Condenser
An accumulator traps excess liquid refrigerant to protect the
compressor from damage.
10. What is the main purpose of a filter-drier?
A. Control airflow
B. Increase pressure
C. Remove moisture and contaminants
D. Reduce noise
Moisture and debris can cause system failure, making filter-driers
essential.
11. Which gas is most commonly used in residential natural gas
furnaces?
A. Propane
B. Methane
C. Butane
D. Hydrogen
Natural gas used in homes is primarily methane.
12. What safety device shuts off gas flow if the pilot flame goes out?
A. Pressure switch
B. Thermocouple or flame sensor
C. Limit switch
D. Rollout switch
These devices detect flame presence and stop gas flow if no flame is
detected.
13. Which law states that energy cannot be created or destroyed?
A. Boyle’s Law
B. Charles’ Law
C. First Law of Thermodynamics
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which organization publishes the International Mechanical Code
(IMC)?
A. ASHRAE
B. International Code Council (ICC)
C. NFPA
D. EPA
The IMC is developed and maintained by the International Code
Council, which also publishes the IBC and IPC.
2. What is the primary purpose of a heat exchanger in a furnace?
A. Circulate combustion air
B. Remove exhaust gases
C. Transfer heat from combustion gases to supply air
D. Regulate gas pressure
The heat exchanger safely transfers heat to the air stream without
mixing combustion gases with indoor air.
3. Which refrigerant property allows heat to be absorbed during
evaporation?
A. Density
B. Pressure
C. Latent heat
D. Viscosity
Latent heat enables a refrigerant to absorb large amounts of heat as
it changes from liquid to vapor.
,4. What device meters refrigerant into the evaporator in a TXV system?
A. Compressor
B. Receiver
C. Thermostatic expansion valve
D. Accumulator
A TXV regulates refrigerant flow based on superheat to protect the
compressor.
5. Which electrical device protects a motor from overload conditions?
A. Fuse
B. Circuit breaker
C. Thermal overload relay
D. Transformer
Thermal overloads respond to excess current over time, preventing
motor overheating.
6. What is the minimum clearance typically required around a gas
furnace for service access?
A. 6 inches
B. 12 inches
C. 30 inches
D. 48 inches
Mechanical codes generally require about 30 inches of working
clearance for service and inspection.
7. Which duct material is most commonly used in residential HVAC
systems?
A. Copper
B. PVC
C. Galvanized steel
D. Cast iron
Galvanized steel is durable, fire-resistant, and widely accepted by
code.
8. What instrument is used to measure airflow in ducts?
A. Manometer
B. Thermometer
C. Anemometer
D. Hygrometer
, An anemometer measures air velocity, which can be used to
calculate airflow.
9. Which component prevents liquid refrigerant from entering the
compressor?
A. Receiver
B. Filter-drier
C. Accumulator
D. Condenser
An accumulator traps excess liquid refrigerant to protect the
compressor from damage.
10. What is the main purpose of a filter-drier?
A. Control airflow
B. Increase pressure
C. Remove moisture and contaminants
D. Reduce noise
Moisture and debris can cause system failure, making filter-driers
essential.
11. Which gas is most commonly used in residential natural gas
furnaces?
A. Propane
B. Methane
C. Butane
D. Hydrogen
Natural gas used in homes is primarily methane.
12. What safety device shuts off gas flow if the pilot flame goes out?
A. Pressure switch
B. Thermocouple or flame sensor
C. Limit switch
D. Rollout switch
These devices detect flame presence and stop gas flow if no flame is
detected.
13. Which law states that energy cannot be created or destroyed?
A. Boyle’s Law
B. Charles’ Law
C. First Law of Thermodynamics
