Apprentice HVAC Technician Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.Which component in a vapor-compression refrigeration system is
responsible for removing heat from the conditioned space by absorbing it
into the refrigerant?
A. Condenser
B. Compressor
C. Evaporator
D. Expansion valve
Answer: C. Evaporator
The evaporator absorbs heat from the indoor air as the refrigerant
changes from a low-pressure liquid mixture into a vapor, allowing cooling
to occur within the conditioned space.
2. What is the primary function of the compressor in a refrigeration
cycle?
A. Reduce refrigerant pressure before entering the evaporator
B. Increase refrigerant pressure and move refrigerant through the system
C. Remove moisture from the refrigerant
D. Convert liquid refrigerant into a gas inside the evaporator
,Answer: B. Increase refrigerant pressure and move refrigerant through the
system
The compressor raises the pressure and temperature of refrigerant vapor
while circulating refrigerant throughout the refrigeration system.
3. Which refrigerant property allows it to absorb large amounts of heat
during evaporation?
A. High density
B. Low boiling point
C. High viscosity
D. Low pressure rating
Answer: B. Low boiling point
A refrigerant’s low boiling point allows it to evaporate at temperatures
below normal room temperature, absorbing heat during the phase change.
4. What instrument is commonly used by HVAC technicians to measure
refrigerant pressure?
A. Clamp meter
B. Manifold gauge set
C. Thermocouple
D. Anemometer
Answer: B. Manifold gauge set
A manifold gauge set measures low-side and high-side refrigerant
pressures, helping technicians diagnose system operation and charge
levels.
5. A dirty air filter in an HVAC system can cause which of the following
problems?
,A. Increased airflow
B. Reduced energy consumption
C. Restricted airflow and reduced efficiency
D. Higher refrigerant capacity
Answer: C. Restricted airflow and reduced efficiency
A clogged filter restricts air movement across the system, reducing
performance, increasing energy use, and potentially causing equipment
damage.
6. What is the purpose of the condenser coil in an air-conditioning
system?
A. Absorb heat from indoor air
B. Release heat from refrigerant to the outdoor environment
C. Reduce electrical voltage
D. Control airflow through ductwork
Answer: B. Release heat from refrigerant to the outdoor environment
The condenser coil removes heat from the refrigerant after compression
and rejects it outdoors, allowing the refrigerant to condense into a liquid.
7. Which electrical component starts the compressor motor by providing
additional starting torque?
A. Capacitor
B. Thermostat
C. Transformer
D. Contactor
Answer: A. Capacitor
A compressor start capacitor provides extra electrical energy during
startup to help the motor overcome initial resistance and begin rotating.
, 8. What voltage is commonly supplied to residential HVAC equipment in
North America?
A. 12 volts
B. 24 volts
C. 120/240 volts
D. 480 volts
Answer: C. 120/240 volts
Residential HVAC systems commonly use 120 volts for controls and
accessories and 240 volts for larger components such as compressors and
electric heaters.
9. What is the purpose of a thermostat in an HVAC system?
A. Increase refrigerant pressure
B. Measure humidity only
C. Control system operation based on temperature settings
D. Remove contaminants from refrigerant
Answer: C. Control system operation based on temperature settings
A thermostat monitors room temperature and signals HVAC equipment to
operate when heating or cooling is required.
10. Which component converts high-pressure liquid refrigerant into
a lower-pressure mixture before entering the evaporator?
A. Compressor
B. Expansion device
C. Condenser fan
D. Receiver
Answer: B. Expansion device
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.Which component in a vapor-compression refrigeration system is
responsible for removing heat from the conditioned space by absorbing it
into the refrigerant?
A. Condenser
B. Compressor
C. Evaporator
D. Expansion valve
Answer: C. Evaporator
The evaporator absorbs heat from the indoor air as the refrigerant
changes from a low-pressure liquid mixture into a vapor, allowing cooling
to occur within the conditioned space.
2. What is the primary function of the compressor in a refrigeration
cycle?
A. Reduce refrigerant pressure before entering the evaporator
B. Increase refrigerant pressure and move refrigerant through the system
C. Remove moisture from the refrigerant
D. Convert liquid refrigerant into a gas inside the evaporator
,Answer: B. Increase refrigerant pressure and move refrigerant through the
system
The compressor raises the pressure and temperature of refrigerant vapor
while circulating refrigerant throughout the refrigeration system.
3. Which refrigerant property allows it to absorb large amounts of heat
during evaporation?
A. High density
B. Low boiling point
C. High viscosity
D. Low pressure rating
Answer: B. Low boiling point
A refrigerant’s low boiling point allows it to evaporate at temperatures
below normal room temperature, absorbing heat during the phase change.
4. What instrument is commonly used by HVAC technicians to measure
refrigerant pressure?
A. Clamp meter
B. Manifold gauge set
C. Thermocouple
D. Anemometer
Answer: B. Manifold gauge set
A manifold gauge set measures low-side and high-side refrigerant
pressures, helping technicians diagnose system operation and charge
levels.
5. A dirty air filter in an HVAC system can cause which of the following
problems?
,A. Increased airflow
B. Reduced energy consumption
C. Restricted airflow and reduced efficiency
D. Higher refrigerant capacity
Answer: C. Restricted airflow and reduced efficiency
A clogged filter restricts air movement across the system, reducing
performance, increasing energy use, and potentially causing equipment
damage.
6. What is the purpose of the condenser coil in an air-conditioning
system?
A. Absorb heat from indoor air
B. Release heat from refrigerant to the outdoor environment
C. Reduce electrical voltage
D. Control airflow through ductwork
Answer: B. Release heat from refrigerant to the outdoor environment
The condenser coil removes heat from the refrigerant after compression
and rejects it outdoors, allowing the refrigerant to condense into a liquid.
7. Which electrical component starts the compressor motor by providing
additional starting torque?
A. Capacitor
B. Thermostat
C. Transformer
D. Contactor
Answer: A. Capacitor
A compressor start capacitor provides extra electrical energy during
startup to help the motor overcome initial resistance and begin rotating.
, 8. What voltage is commonly supplied to residential HVAC equipment in
North America?
A. 12 volts
B. 24 volts
C. 120/240 volts
D. 480 volts
Answer: C. 120/240 volts
Residential HVAC systems commonly use 120 volts for controls and
accessories and 240 volts for larger components such as compressors and
electric heaters.
9. What is the purpose of a thermostat in an HVAC system?
A. Increase refrigerant pressure
B. Measure humidity only
C. Control system operation based on temperature settings
D. Remove contaminants from refrigerant
Answer: C. Control system operation based on temperature settings
A thermostat monitors room temperature and signals HVAC equipment to
operate when heating or cooling is required.
10. Which component converts high-pressure liquid refrigerant into
a lower-pressure mixture before entering the evaporator?
A. Compressor
B. Expansion device
C. Condenser fan
D. Receiver
Answer: B. Expansion device
