UA STAR HVACR Mastery Certification Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary function of a compressor in a refrigeration
system?
A. Absorb heat from the environment
B. Reduce refrigerant pressure
C. Increase refrigerant pressure and circulate it through the
system
D. Filter contaminants from refrigerant
C
The compressor raises the pressure of the refrigerant, enabling it
to flow through the condenser and evaporator.
2. Which refrigerant is considered to have zero ozone depletion
potential (ODP) and low global warming potential (GWP)?
A. R-22
B. R-134a
C. R-410A
D. R-123
C
R-410A is a commonly used HFC refrigerant with no ODP and
relatively low GWP compared to older CFCs or HCFCs.
3. In a split air conditioning system, the evaporator is located:
A. Outdoors in the condensing unit
, B. Indoors in the air handler or furnace
C. In the compressor
D. In the ductwork outside
B
The evaporator coil absorbs heat from indoor air and is typically
inside the air handling unit.
4. What does SEER stand for in HVAC systems?
A. Seasonal Energy Efficiency Ratio
B. Standard Electrical Energy Rating
C. System Efficiency Energy Report
D. Seasonal Energy Evaluation Ratio
A
SEER measures cooling efficiency over a typical cooling season.
5. Superheat is measured at which point in a refrigeration system?
A. Evaporator inlet
B. Evaporator outlet
C. Condenser inlet
D. Compressor outlet
B
Superheat is the temperature of the refrigerant vapor above its
saturation point, measured at the evaporator outlet.
6. What is the purpose of a thermostatic expansion valve (TXV)?
A. Regulate refrigerant flow into the evaporator based on
superheat
B. Increase refrigerant pressure to the condenser
C. Filter impurities from the system
D. Compress the refrigerant for circulation
, A
A TXV controls the amount of refrigerant entering the evaporator
to maintain proper superheat.
7. Which type of electrical motor is commonly used in HVAC
blowers?
A. Induction motor
B. Stepper motor
C. Synchronous motor
D. Servo motor
A
Induction motors are reliable, efficient, and widely used in HVAC
blower applications.
8. Which component removes heat from refrigerant in a vapor-
compression cycle?
A. Evaporator
B. Condenser
C. Compressor
D. TXV
B
The condenser transfers heat from high-pressure refrigerant to the
outside air, condensing it into a liquid.
9. What is the primary purpose of an air filter in an HVAC system?
A. Reduce refrigerant temperature
B. Remove particulate matter from the air
C. Increase system pressure
D. Control humidity
B
, Air filters protect equipment and improve indoor air quality by
trapping dust, pollen, and other particles.
10. When diagnosing low suction pressure in an air conditioning
system, the technician should first check:
A. Compressor motor voltage
B. Refrigerant charge and airflow
C. Condenser coil temperature
D. Thermostat calibration
B
Low suction pressure is often caused by low refrigerant charge or
restricted airflow through the evaporator.
11. The process of transferring heat from one medium to
another is called:
A. Condensation
B. Refrigeration
C. Heat exchange
D. Superheating
C
Heat exchange is the transfer of thermal energy between two
fluids or a fluid and a solid.
12. In an electric heat pump system, the reversing valve:
A. Converts electricity to heat
B. Reverses the flow of refrigerant to switch between heating and
cooling
C. Filters the refrigerant
D. Increases compressor efficiency
B
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary function of a compressor in a refrigeration
system?
A. Absorb heat from the environment
B. Reduce refrigerant pressure
C. Increase refrigerant pressure and circulate it through the
system
D. Filter contaminants from refrigerant
C
The compressor raises the pressure of the refrigerant, enabling it
to flow through the condenser and evaporator.
2. Which refrigerant is considered to have zero ozone depletion
potential (ODP) and low global warming potential (GWP)?
A. R-22
B. R-134a
C. R-410A
D. R-123
C
R-410A is a commonly used HFC refrigerant with no ODP and
relatively low GWP compared to older CFCs or HCFCs.
3. In a split air conditioning system, the evaporator is located:
A. Outdoors in the condensing unit
, B. Indoors in the air handler or furnace
C. In the compressor
D. In the ductwork outside
B
The evaporator coil absorbs heat from indoor air and is typically
inside the air handling unit.
4. What does SEER stand for in HVAC systems?
A. Seasonal Energy Efficiency Ratio
B. Standard Electrical Energy Rating
C. System Efficiency Energy Report
D. Seasonal Energy Evaluation Ratio
A
SEER measures cooling efficiency over a typical cooling season.
5. Superheat is measured at which point in a refrigeration system?
A. Evaporator inlet
B. Evaporator outlet
C. Condenser inlet
D. Compressor outlet
B
Superheat is the temperature of the refrigerant vapor above its
saturation point, measured at the evaporator outlet.
6. What is the purpose of a thermostatic expansion valve (TXV)?
A. Regulate refrigerant flow into the evaporator based on
superheat
B. Increase refrigerant pressure to the condenser
C. Filter impurities from the system
D. Compress the refrigerant for circulation
, A
A TXV controls the amount of refrigerant entering the evaporator
to maintain proper superheat.
7. Which type of electrical motor is commonly used in HVAC
blowers?
A. Induction motor
B. Stepper motor
C. Synchronous motor
D. Servo motor
A
Induction motors are reliable, efficient, and widely used in HVAC
blower applications.
8. Which component removes heat from refrigerant in a vapor-
compression cycle?
A. Evaporator
B. Condenser
C. Compressor
D. TXV
B
The condenser transfers heat from high-pressure refrigerant to the
outside air, condensing it into a liquid.
9. What is the primary purpose of an air filter in an HVAC system?
A. Reduce refrigerant temperature
B. Remove particulate matter from the air
C. Increase system pressure
D. Control humidity
B
, Air filters protect equipment and improve indoor air quality by
trapping dust, pollen, and other particles.
10. When diagnosing low suction pressure in an air conditioning
system, the technician should first check:
A. Compressor motor voltage
B. Refrigerant charge and airflow
C. Condenser coil temperature
D. Thermostat calibration
B
Low suction pressure is often caused by low refrigerant charge or
restricted airflow through the evaporator.
11. The process of transferring heat from one medium to
another is called:
A. Condensation
B. Refrigeration
C. Heat exchange
D. Superheating
C
Heat exchange is the transfer of thermal energy between two
fluids or a fluid and a solid.
12. In an electric heat pump system, the reversing valve:
A. Converts electricity to heat
B. Reverses the flow of refrigerant to switch between heating and
cooling
C. Filters the refrigerant
D. Increases compressor efficiency
B
