Georgia Conditioned Air Contractor
Class I Examination Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which component primarily removes heat from the refrigerant in a vapor-
compression system?
A. Expansion valve
B. Condenser
C. Evaporator
D. Compressor
Rationale: The condenser is responsible for rejecting heat absorbed in the
evaporator and compression process. As high-pressure, high-temperature
refrigerant vapor enters the condenser, it releases heat to the surrounding air or
water and condenses into a liquid. The evaporator absorbs heat from the
conditioned space, the compressor raises refrigerant pressure and temperature,
and the expansion valve meters refrigerant flow while reducing pressure.
Therefore, the condenser is the correct heat rejection component in the
refrigeration cycle.
2. What is the primary function of a thermostatic expansion valve (TXV)?
A. Compress refrigerant vapor
B. Regulate refrigerant flow into the evaporator
,C. Condense refrigerant vapor
D. Filter moisture from refrigerant
Rationale: A TXV controls the amount of refrigerant entering the evaporator
based on temperature and pressure feedback (superheat). This ensures optimal
evaporator performance and prevents liquid refrigerant from returning to the
compressor. It does not compress, condense, or filter refrigerant; its sole function
is modulation of refrigerant flow to maintain system efficiency and protect
equipment.
3. Which refrigerant property determines the pressure-temperature
relationship?
A. Saturation characteristics
B. Latent heat only
C. Specific gravity
D. Viscosity index
Rationale: Refrigerants operate based on saturation pressure-temperature
relationships, meaning each refrigerant has a predictable boiling point at a
given pressure. This property allows technicians to diagnose system
performance using pressure readings. Latent heat, viscosity, and specific gravity
affect performance but do not define the core pressure-temperature curve used
in HVAC diagnostics.
4. What device protects a compressor from liquid refrigerant slugging?
A. Filter drier
B. Expansion valve
C. Condenser fan
D. Accumulator
Rationale: The accumulator is installed in the suction line to prevent liquid
refrigerant from entering the compressor. It temporarily stores excess liquid
,refrigerant and allows only vapor to reach the compressor, preventing
mechanical damage from slugging. Other components do not serve this
protective function directly.
5. What is the primary purpose of superheat in an HVAC system?
A. Increase refrigerant pressure
B. Subcool liquid refrigerant
C. Ensure complete evaporation before suction line
D. Reduce compressor amperage only
Rationale: Superheat ensures that all refrigerant has fully vaporized in the
evaporator before entering the compressor. This prevents liquid refrigerant from
causing compressor damage. It is a key diagnostic value used to adjust TXV
operation and system performance.
6. What determines airflow in a duct system?
A. Refrigerant pressure
B. Static pressure and fan performance
C. Compressor size
D. Evaporator temperature only
Rationale: Airflow is primarily driven by the blower fan and is influenced by total
external static pressure in the duct system. Restrictions, duct size, and filter
resistance affect airflow. Refrigerant pressure and evaporator temperature are
unrelated to air movement dynamics.
7. Which instrument is used to measure air velocity in ducts?
A. Manometer
B. Psychrometer
, C. Thermometer
D. Anemometer
Rationale: An anemometer measures air velocity directly in feet per minute or
meters per second. Manometers measure pressure, psychrometers measure
humidity, and thermometers measure temperature, making them unsuitable for
airflow measurement.
8. What is the function of a heat pump reversing valve?
A. Increase refrigerant pressure
B. Control compressor speed
C. Regulate airflow direction
D. Switch between heating and cooling modes
Rationale: The reversing valve changes refrigerant flow direction, allowing the
system to alternate between heating and cooling modes. It does not control
pressure, airflow, or compressor speed directly.
9. What is the purpose of subcooling in a refrigeration system?
A. Increase suction pressure
B. Improve airflow efficiency
C. Ensure liquid refrigerant is fully condensed before expansion valve
D. Raise evaporator temperature
Rationale: Subcooling ensures that refrigerant leaving the condenser is fully
liquid with no vapor bubbles, improving system efficiency and preventing flash
gas before the expansion device.
10.Which safety device prevents excessive system pressure?
A. Expansion valve
B. Thermostat
Class I Examination Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which component primarily removes heat from the refrigerant in a vapor-
compression system?
A. Expansion valve
B. Condenser
C. Evaporator
D. Compressor
Rationale: The condenser is responsible for rejecting heat absorbed in the
evaporator and compression process. As high-pressure, high-temperature
refrigerant vapor enters the condenser, it releases heat to the surrounding air or
water and condenses into a liquid. The evaporator absorbs heat from the
conditioned space, the compressor raises refrigerant pressure and temperature,
and the expansion valve meters refrigerant flow while reducing pressure.
Therefore, the condenser is the correct heat rejection component in the
refrigeration cycle.
2. What is the primary function of a thermostatic expansion valve (TXV)?
A. Compress refrigerant vapor
B. Regulate refrigerant flow into the evaporator
,C. Condense refrigerant vapor
D. Filter moisture from refrigerant
Rationale: A TXV controls the amount of refrigerant entering the evaporator
based on temperature and pressure feedback (superheat). This ensures optimal
evaporator performance and prevents liquid refrigerant from returning to the
compressor. It does not compress, condense, or filter refrigerant; its sole function
is modulation of refrigerant flow to maintain system efficiency and protect
equipment.
3. Which refrigerant property determines the pressure-temperature
relationship?
A. Saturation characteristics
B. Latent heat only
C. Specific gravity
D. Viscosity index
Rationale: Refrigerants operate based on saturation pressure-temperature
relationships, meaning each refrigerant has a predictable boiling point at a
given pressure. This property allows technicians to diagnose system
performance using pressure readings. Latent heat, viscosity, and specific gravity
affect performance but do not define the core pressure-temperature curve used
in HVAC diagnostics.
4. What device protects a compressor from liquid refrigerant slugging?
A. Filter drier
B. Expansion valve
C. Condenser fan
D. Accumulator
Rationale: The accumulator is installed in the suction line to prevent liquid
refrigerant from entering the compressor. It temporarily stores excess liquid
,refrigerant and allows only vapor to reach the compressor, preventing
mechanical damage from slugging. Other components do not serve this
protective function directly.
5. What is the primary purpose of superheat in an HVAC system?
A. Increase refrigerant pressure
B. Subcool liquid refrigerant
C. Ensure complete evaporation before suction line
D. Reduce compressor amperage only
Rationale: Superheat ensures that all refrigerant has fully vaporized in the
evaporator before entering the compressor. This prevents liquid refrigerant from
causing compressor damage. It is a key diagnostic value used to adjust TXV
operation and system performance.
6. What determines airflow in a duct system?
A. Refrigerant pressure
B. Static pressure and fan performance
C. Compressor size
D. Evaporator temperature only
Rationale: Airflow is primarily driven by the blower fan and is influenced by total
external static pressure in the duct system. Restrictions, duct size, and filter
resistance affect airflow. Refrigerant pressure and evaporator temperature are
unrelated to air movement dynamics.
7. Which instrument is used to measure air velocity in ducts?
A. Manometer
B. Psychrometer
, C. Thermometer
D. Anemometer
Rationale: An anemometer measures air velocity directly in feet per minute or
meters per second. Manometers measure pressure, psychrometers measure
humidity, and thermometers measure temperature, making them unsuitable for
airflow measurement.
8. What is the function of a heat pump reversing valve?
A. Increase refrigerant pressure
B. Control compressor speed
C. Regulate airflow direction
D. Switch between heating and cooling modes
Rationale: The reversing valve changes refrigerant flow direction, allowing the
system to alternate between heating and cooling modes. It does not control
pressure, airflow, or compressor speed directly.
9. What is the purpose of subcooling in a refrigeration system?
A. Increase suction pressure
B. Improve airflow efficiency
C. Ensure liquid refrigerant is fully condensed before expansion valve
D. Raise evaporator temperature
Rationale: Subcooling ensures that refrigerant leaving the condenser is fully
liquid with no vapor bubbles, improving system efficiency and preventing flash
gas before the expansion device.
10.Which safety device prevents excessive system pressure?
A. Expansion valve
B. Thermostat
