Alabama Heating & Air Conditioning Contractors
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
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1. What is the primary purpose of a Manual J residential load
calculation?
a. To determine duct leakage
b. To size electrical conductors
c. To determine the heating and cooling loads of a building
d. To determine refrigerant charge
Rationale: Manual J is used to calculate the heating and cooling
requirements of a residence. Proper load calculations help prevent
oversizing or undersizing equipment and provide the basis for selecting
appropriately sized HVAC equipment.
2. Which component removes heat from indoor air in a typical split-
system air conditioner?
,a. Condenser coil
b. Compressor
c. Evaporator coil
d. Receiver
Rationale: The evaporator coil is located on the indoor side of the
system and absorbs heat from indoor air as refrigerant evaporates
within the coil.
3. What is the primary function of a compressor in a vapor-
compression refrigeration system?
a. Remove moisture from the air
b. Condense liquid refrigerant
c. Raise the pressure and temperature of the refrigerant vapor
d. Reduce refrigerant pressure
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor before it enters the condenser.
4. Which component changes high-pressure refrigerant vapor into a
liquid?
a. Evaporator
b. Expansion valve
,c. Accumulator
d. Condenser
Rationale: The condenser rejects heat from the refrigerant to the
surrounding environment. As heat is removed, the high-pressure vapor
condenses into a high-pressure liquid.
5. What is the primary purpose of a thermostatic expansion valve
(TXV)?
a. Increase compressor speed
b. Control refrigerant flow into the evaporator
c. Increase condenser pressure
d. Remove noncondensable gases
Rationale: A TXV meters refrigerant into the evaporator while
responding to evaporator outlet conditions. Proper metering helps
maintain the desired superheat and promotes efficient evaporator
operation.
6. What does superheat describe in a refrigeration system?
a. The temperature of liquid below its saturation temperature
b. The temperature of vapor above its saturation temperature
c. The pressure difference across the condenser
d. The temperature difference between indoor and outdoor air
, Rationale: Superheat is the amount by which refrigerant vapor
temperature exceeds its saturation temperature at a given pressure.
Measuring superheat is useful when diagnosing evaporator and
refrigerant-feed conditions.
7. What does subcooling describe?
a. Vapor below its boiling point
b. Liquid refrigerant below its saturation temperature
c. Air below room temperature
d. Refrigerant above its condensing temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled below its
saturation temperature at the corresponding pressure. It is commonly
evaluated at the condenser outlet or liquid line.
8. Which instrument is commonly used to measure refrigerant
pressure?
a. Psychrometer
b. Anemometer
c. Manifold gauge set
d. Megohmmeter
Examination Questions and Correct Answers
(Verified Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary purpose of a Manual J residential load
calculation?
a. To determine duct leakage
b. To size electrical conductors
c. To determine the heating and cooling loads of a building
d. To determine refrigerant charge
Rationale: Manual J is used to calculate the heating and cooling
requirements of a residence. Proper load calculations help prevent
oversizing or undersizing equipment and provide the basis for selecting
appropriately sized HVAC equipment.
2. Which component removes heat from indoor air in a typical split-
system air conditioner?
,a. Condenser coil
b. Compressor
c. Evaporator coil
d. Receiver
Rationale: The evaporator coil is located on the indoor side of the
system and absorbs heat from indoor air as refrigerant evaporates
within the coil.
3. What is the primary function of a compressor in a vapor-
compression refrigeration system?
a. Remove moisture from the air
b. Condense liquid refrigerant
c. Raise the pressure and temperature of the refrigerant vapor
d. Reduce refrigerant pressure
Rationale: The compressor takes low-pressure refrigerant vapor from
the evaporator and compresses it into a high-pressure, high-
temperature vapor before it enters the condenser.
4. Which component changes high-pressure refrigerant vapor into a
liquid?
a. Evaporator
b. Expansion valve
,c. Accumulator
d. Condenser
Rationale: The condenser rejects heat from the refrigerant to the
surrounding environment. As heat is removed, the high-pressure vapor
condenses into a high-pressure liquid.
5. What is the primary purpose of a thermostatic expansion valve
(TXV)?
a. Increase compressor speed
b. Control refrigerant flow into the evaporator
c. Increase condenser pressure
d. Remove noncondensable gases
Rationale: A TXV meters refrigerant into the evaporator while
responding to evaporator outlet conditions. Proper metering helps
maintain the desired superheat and promotes efficient evaporator
operation.
6. What does superheat describe in a refrigeration system?
a. The temperature of liquid below its saturation temperature
b. The temperature of vapor above its saturation temperature
c. The pressure difference across the condenser
d. The temperature difference between indoor and outdoor air
, Rationale: Superheat is the amount by which refrigerant vapor
temperature exceeds its saturation temperature at a given pressure.
Measuring superheat is useful when diagnosing evaporator and
refrigerant-feed conditions.
7. What does subcooling describe?
a. Vapor below its boiling point
b. Liquid refrigerant below its saturation temperature
c. Air below room temperature
d. Refrigerant above its condensing temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled below its
saturation temperature at the corresponding pressure. It is commonly
evaluated at the condenser outlet or liquid line.
8. Which instrument is commonly used to measure refrigerant
pressure?
a. Psychrometer
b. Anemometer
c. Manifold gauge set
d. Megohmmeter
