CT HVAC Contractor Exam Questions
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
Download Pdf
1. What is the primary purpose of a refrigeration system’s
evaporator?
A. Reject heat to the outdoor environment
B. Compress refrigerant vapor
C. Meter refrigerant into the system
D. Absorb heat from the conditioned space
Rationale: The evaporator absorbs heat from the air, water, or other
medium being cooled. Refrigerant entering the evaporator at low
pressure and temperature absorbs this heat as it changes state from
liquid to vapor.
, 2. Which component raises the pressure and temperature of
refrigerant vapor in a typical vapor-compression refrigeration
cycle?
A. Condenser
B. Expansion valve
C. Compressor
D. Evaporator
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.
3. What is the primary function of the condenser in an air-
conditioning system?
A. Increase refrigerant flow rate
B. Reject heat from the refrigerant
C. Reduce suction pressure
D. Add moisture to the conditioned air
Rationale: The condenser removes heat from the refrigerant and
transfers it to outdoor air, water, or another heat sink. The refrigerant
changes from vapor to liquid during condensation.
, 4. Which device controls the amount of refrigerant entering an
evaporator?
A. Accumulator
B. Receiver
C. Compressor
D. Metering device
Rationale: A metering device, such as a thermostatic expansion valve
or electronic expansion valve, regulates refrigerant flow into the
evaporator while producing the necessary pressure drop.
5. What does superheat describe in a refrigeration system?
A. Liquid refrigerant temperature below its boiling point
B. Vapor temperature above its saturation temperature
C. Condenser temperature below outdoor temperature
D. Refrigerant pressure above the maximum allowable pressure
Rationale: Superheat is the number of degrees a refrigerant vapor is
heated above its saturation temperature at a particular pressure.
Proper superheat helps ensure that liquid refrigerant does not reach
the compressor.
6. What does subcooling indicate?
, A. Vapor temperature above saturation temperature
B. Compressor discharge temperature
C. Liquid temperature below its saturation temperature
D. Evaporator temperature above room temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled below
its saturation temperature at the measured pressure. It helps ensure
that solid liquid refrigerant reaches the metering device.
7. Which refrigerant condition is most likely to cause liquid slugging
in a reciprocating compressor?
A. Excessive superheat
B. Low condenser pressure
C. Liquid refrigerant entering the compressor
D. Low evaporator pressure without liquid carryover
Rationale: Compressors are designed primarily to compress vapor.
Liquid refrigerant is essentially incompressible and can damage
valves, pistons, connecting rods, or other internal components.
8. What is the purpose of a filter-drier installed in a refrigeration
system?
A. Increase compressor capacity
B. Reduce airflow
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
Download Pdf
1. What is the primary purpose of a refrigeration system’s
evaporator?
A. Reject heat to the outdoor environment
B. Compress refrigerant vapor
C. Meter refrigerant into the system
D. Absorb heat from the conditioned space
Rationale: The evaporator absorbs heat from the air, water, or other
medium being cooled. Refrigerant entering the evaporator at low
pressure and temperature absorbs this heat as it changes state from
liquid to vapor.
, 2. Which component raises the pressure and temperature of
refrigerant vapor in a typical vapor-compression refrigeration
cycle?
A. Condenser
B. Expansion valve
C. Compressor
D. Evaporator
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.
3. What is the primary function of the condenser in an air-
conditioning system?
A. Increase refrigerant flow rate
B. Reject heat from the refrigerant
C. Reduce suction pressure
D. Add moisture to the conditioned air
Rationale: The condenser removes heat from the refrigerant and
transfers it to outdoor air, water, or another heat sink. The refrigerant
changes from vapor to liquid during condensation.
, 4. Which device controls the amount of refrigerant entering an
evaporator?
A. Accumulator
B. Receiver
C. Compressor
D. Metering device
Rationale: A metering device, such as a thermostatic expansion valve
or electronic expansion valve, regulates refrigerant flow into the
evaporator while producing the necessary pressure drop.
5. What does superheat describe in a refrigeration system?
A. Liquid refrigerant temperature below its boiling point
B. Vapor temperature above its saturation temperature
C. Condenser temperature below outdoor temperature
D. Refrigerant pressure above the maximum allowable pressure
Rationale: Superheat is the number of degrees a refrigerant vapor is
heated above its saturation temperature at a particular pressure.
Proper superheat helps ensure that liquid refrigerant does not reach
the compressor.
6. What does subcooling indicate?
, A. Vapor temperature above saturation temperature
B. Compressor discharge temperature
C. Liquid temperature below its saturation temperature
D. Evaporator temperature above room temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled below
its saturation temperature at the measured pressure. It helps ensure
that solid liquid refrigerant reaches the metering device.
7. Which refrigerant condition is most likely to cause liquid slugging
in a reciprocating compressor?
A. Excessive superheat
B. Low condenser pressure
C. Liquid refrigerant entering the compressor
D. Low evaporator pressure without liquid carryover
Rationale: Compressors are designed primarily to compress vapor.
Liquid refrigerant is essentially incompressible and can damage
valves, pistons, connecting rods, or other internal components.
8. What is the purpose of a filter-drier installed in a refrigeration
system?
A. Increase compressor capacity
B. Reduce airflow
