Indiana HVAC Contractor Examination
Practice Test Questions and Correct
Answers (Verified Answers) Plus
Rationales 2025|2026 Q&A | Instant
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1. What is the primary purpose of an HVAC system's air filter?
A. Increase refrigerant pressure
B. Remove airborne particles from circulating air
C. Increase furnace gas pressure
D. Reduce compressor oil temperature
Correct Answer: B. Remove airborne particles from circulating air
Rationale: An air filter captures dust, lint, and other airborne particles before air
circulates through the HVAC system. Proper filter selection and maintenance help
protect equipment and maintain indoor air quality.
2. What happens to sensible heat when air passes over a properly operating
cooling coil?
A. It increases
B. It remains exactly unchanged
C. It decreases
D. It converts entirely into latent heat
Correct Answer: C. It decreases
Rationale: A cooling coil removes sensible heat from the air, lowering its dry-bulb
temperature. If the coil surface is below the air's dew point, latent heat may also
be removed through condensation.
,3. Which component of a vapor-compression refrigeration system raises the
refrigerant's pressure?
A. Compressor
B. Evaporator
C. Expansion device
D. Condenser
Correct Answer: A. Compressor
Rationale: The compressor receives low-pressure vapor from the evaporator and
compresses it into a high-pressure, high-temperature vapor before it enters the
condenser.
4. What is the primary function of the evaporator in an air-conditioning system?
A. Reject heat to outdoor air
B. Increase refrigerant pressure
C. Absorb heat from the conditioned space
D. Store liquid refrigerant
Correct Answer: C. Absorb heat from the conditioned space
Rationale: The evaporator absorbs heat from indoor air as refrigerant changes
state from a low-pressure liquid/vapor mixture toward vapor. This process
provides the cooling effect.
5. What is the primary function of the condenser?
A. Absorb heat from indoor air
B. Reject heat from the refrigerant to another medium
C. Reduce refrigerant pressure through expansion
D. Meter combustion air
Correct Answer: B. Reject heat from the refrigerant to another medium
Rationale: In cooling mode, the condenser rejects heat absorbed from the
conditioned space plus the heat added by compressor operation. Outdoor air
commonly serves as the heat-rejection medium.
6. What is the purpose of a thermostatic expansion valve (TXV)?
,A. Meter refrigerant entering the evaporator
B. Increase compressor speed
C. Remove oil from the condenser
D. Increase suction-line pressure
Correct Answer: A. Meter refrigerant entering the evaporator
Rationale: A TXV regulates refrigerant flow into the evaporator based primarily on
evaporator outlet superheat. Proper metering helps maintain effective evaporator
operation.
7. What does refrigerant superheat represent?
A. Temperature of liquid below its freezing point
B. Temperature of vapor above its saturation temperature
C. Pressure difference between two compressors
D. Temperature difference between outdoor and indoor air
Correct Answer: B. Temperature of vapor above its saturation temperature
Rationale: Superheat is the amount by which a vapor's actual temperature
exceeds its saturation temperature at the measured pressure.
8. What does subcooling indicate in a refrigeration system?
A. Liquid temperature below its saturation temperature at a given pressure
B. Vapor temperature above its saturation temperature
C. Compressor discharge temperature above normal
D. Evaporator pressure below atmospheric pressure
Correct Answer: A. Liquid temperature below its saturation temperature at a
given pressure
Rationale: Subcooling occurs when liquid refrigerant is cooled below its saturation
temperature at the corresponding pressure. It is commonly measured at the
condenser outlet or liquid line.
9. Which instrument is commonly used to measure refrigerant pressure during
system service?
A. Manifold gauge set
B. Clamp meter
, C. Psychrometer
D. Megohmmeter
Correct Answer: A. Manifold gauge set
Rationale: A refrigerant manifold gauge set allows a technician to measure system
pressures and, depending on the equipment and gauge set, perform controlled
charging or recovery-related procedures.
10. Why should a refrigeration system be properly evacuated before charging?
A. To increase compressor horsepower
B. To remove air and moisture from the system
C. To increase condenser airflow
D. To raise indoor humidity
Correct Answer: B. To remove air and moisture from the system
Rationale: Air and moisture are contaminants. Moisture can contribute to
corrosion, freezing at restrictions, and undesirable chemical reactions, while
noncondensable gases can adversely affect system pressures and performance.
11. Which component changes a high-pressure liquid refrigerant into a lower-
pressure mixture before it enters the evaporator?
A. Compressor
B. Condenser
C. Expansion device
D. Accumulator
Correct Answer: C. Expansion device
Rationale: The expansion device creates a pressure drop between the high side
and low side of the refrigeration circuit and meters refrigerant into the
evaporator.
12. What is the primary purpose of a compressor crankcase heater when one is
provided?
A. Prevent refrigerant migration and oil dilution during certain off cycles
B. Increase condenser airflow
Practice Test Questions and Correct
Answers (Verified Answers) Plus
Rationales 2025|2026 Q&A | Instant
download Pdf
1. What is the primary purpose of an HVAC system's air filter?
A. Increase refrigerant pressure
B. Remove airborne particles from circulating air
C. Increase furnace gas pressure
D. Reduce compressor oil temperature
Correct Answer: B. Remove airborne particles from circulating air
Rationale: An air filter captures dust, lint, and other airborne particles before air
circulates through the HVAC system. Proper filter selection and maintenance help
protect equipment and maintain indoor air quality.
2. What happens to sensible heat when air passes over a properly operating
cooling coil?
A. It increases
B. It remains exactly unchanged
C. It decreases
D. It converts entirely into latent heat
Correct Answer: C. It decreases
Rationale: A cooling coil removes sensible heat from the air, lowering its dry-bulb
temperature. If the coil surface is below the air's dew point, latent heat may also
be removed through condensation.
,3. Which component of a vapor-compression refrigeration system raises the
refrigerant's pressure?
A. Compressor
B. Evaporator
C. Expansion device
D. Condenser
Correct Answer: A. Compressor
Rationale: The compressor receives low-pressure vapor from the evaporator and
compresses it into a high-pressure, high-temperature vapor before it enters the
condenser.
4. What is the primary function of the evaporator in an air-conditioning system?
A. Reject heat to outdoor air
B. Increase refrigerant pressure
C. Absorb heat from the conditioned space
D. Store liquid refrigerant
Correct Answer: C. Absorb heat from the conditioned space
Rationale: The evaporator absorbs heat from indoor air as refrigerant changes
state from a low-pressure liquid/vapor mixture toward vapor. This process
provides the cooling effect.
5. What is the primary function of the condenser?
A. Absorb heat from indoor air
B. Reject heat from the refrigerant to another medium
C. Reduce refrigerant pressure through expansion
D. Meter combustion air
Correct Answer: B. Reject heat from the refrigerant to another medium
Rationale: In cooling mode, the condenser rejects heat absorbed from the
conditioned space plus the heat added by compressor operation. Outdoor air
commonly serves as the heat-rejection medium.
6. What is the purpose of a thermostatic expansion valve (TXV)?
,A. Meter refrigerant entering the evaporator
B. Increase compressor speed
C. Remove oil from the condenser
D. Increase suction-line pressure
Correct Answer: A. Meter refrigerant entering the evaporator
Rationale: A TXV regulates refrigerant flow into the evaporator based primarily on
evaporator outlet superheat. Proper metering helps maintain effective evaporator
operation.
7. What does refrigerant superheat represent?
A. Temperature of liquid below its freezing point
B. Temperature of vapor above its saturation temperature
C. Pressure difference between two compressors
D. Temperature difference between outdoor and indoor air
Correct Answer: B. Temperature of vapor above its saturation temperature
Rationale: Superheat is the amount by which a vapor's actual temperature
exceeds its saturation temperature at the measured pressure.
8. What does subcooling indicate in a refrigeration system?
A. Liquid temperature below its saturation temperature at a given pressure
B. Vapor temperature above its saturation temperature
C. Compressor discharge temperature above normal
D. Evaporator pressure below atmospheric pressure
Correct Answer: A. Liquid temperature below its saturation temperature at a
given pressure
Rationale: Subcooling occurs when liquid refrigerant is cooled below its saturation
temperature at the corresponding pressure. It is commonly measured at the
condenser outlet or liquid line.
9. Which instrument is commonly used to measure refrigerant pressure during
system service?
A. Manifold gauge set
B. Clamp meter
, C. Psychrometer
D. Megohmmeter
Correct Answer: A. Manifold gauge set
Rationale: A refrigerant manifold gauge set allows a technician to measure system
pressures and, depending on the equipment and gauge set, perform controlled
charging or recovery-related procedures.
10. Why should a refrigeration system be properly evacuated before charging?
A. To increase compressor horsepower
B. To remove air and moisture from the system
C. To increase condenser airflow
D. To raise indoor humidity
Correct Answer: B. To remove air and moisture from the system
Rationale: Air and moisture are contaminants. Moisture can contribute to
corrosion, freezing at restrictions, and undesirable chemical reactions, while
noncondensable gases can adversely affect system pressures and performance.
11. Which component changes a high-pressure liquid refrigerant into a lower-
pressure mixture before it enters the evaporator?
A. Compressor
B. Condenser
C. Expansion device
D. Accumulator
Correct Answer: C. Expansion device
Rationale: The expansion device creates a pressure drop between the high side
and low side of the refrigeration circuit and meters refrigerant into the
evaporator.
12. What is the primary purpose of a compressor crankcase heater when one is
provided?
A. Prevent refrigerant migration and oil dilution during certain off cycles
B. Increase condenser airflow
