STAR HVAC MASTERY EXAM
2025/2026
COMPLETE QUESTIONS WITH CORRECT
DETAILED ANSWERS || 100%
GUARANTEED PASS BRAND NEW
VERSION
Description: This comprehensive revision set covers Refrigeration Fundamentals,
Refrigerants, Compressors, Condensers, Evaporators, Metering Devices, Electrical
Controls, Motors, System Troubleshooting, Load Calculations, Ductwork, Indoor
Air Quality, Heat Pumps, Chillers, and Safety Practices for HVAC mastery.
Key Words: HVAC, Refrigeration Cycle, Superheat, Subcooling, Compressor,
Condenser, Evaporator, TXV, PSI, BTU, Tonnage, Airflow, Thermostat, Heat Pump,
Troubleshooting, Safety
SECTION 1: REFRIGERATION FUNDAMENTALS (Q1–Q20)
Q1. What is the primary function of a refrigerant in an HVAC system?
A) To lubricate the compressor
B) To absorb and release heat during phase changes ✅
C) To filter contaminants from the air
D) To increase electrical conductivity
Q2. Which component in the refrigeration cycle is responsible for rejecting heat to the
outdoors?
A) Evaporator
,B) Compressor
C) Condenser ✅
D) Metering device
Q3. What is the unit of measurement for heat quantity in HVAC?
A) Pascal
B) BTU ✅
C) Ampere
D) Hertz
Q4. The refrigeration cycle begins at which component?
A) Condenser
B) Compressor ✅
C) Evaporator
D) Expansion valve
Q5. What does one ton of refrigeration equal in BTUs per hour?
A) 6,000
B) 10,000
C) 12,000 ✅
D) 15,000
Q6. Which law of thermodynamics states that heat flows from hot to cold?
A) First law
B) Second law ✅
C) Third law
D) Zeroth law
Q7. What is the state of refrigerant entering the compressor?
A) High-pressure liquid
B) Low-pressure superheated vapor ✅
C) Low-pressure liquid
D) High-pressure vapor
,Q8. Sensible heat is defined as:
A) Heat that changes the state of a substance
B) Heat that changes the temperature of a substance ✅
C) Heat that is lost through radiation
D) Heat that is generated electrically
Q9. Latent heat is best described as:
A) Heat that changes temperature
B) Heat that changes the state without changing temperature ✅
C) Heat that is measured in watts
D) Heat that is always lost
Q10. What is the boiling point of water at standard atmospheric pressure?
A) 32°F
B) 100°F
C) 212°F ✅
D) 273°F
Q11. Which of the following is a primary refrigerant?
A) R-134a ✅
B) Glycol
C) Brine
D) Water
Q12. What instrument measures the pressure in a refrigeration system?
A) Thermometer
B) Manifold gauge ✅
C) Multimeter
D) Anemometer
Q13. What does the term "superheat" refer to?
A) Heat added to liquid refrigerant
B) Heat added to vapor above its saturation point ✅
, C) Heat removed from vapor
D) Heat lost in the condenser
Q14. What does "subcooling" mean?
A) Cooling vapor below its saturation point
B) Cooling liquid below its saturation temperature ✅
C) Heating liquid above saturation
D) Cooling the compressor
Q15. Which of the following best describes a hermetic compressor?
A) A compressor that is open and belt-driven
B) A compressor sealed within a welded housing with the motor ✅
C) A compressor that uses no oil
D) A compressor that only works with water
Q16. What is the purpose of a receiver in a refrigeration system?
A) To store refrigerant liquid ✅
B) To compress refrigerant
C) To filter refrigerant
D) To measure refrigerant temperature
Q17. What is the primary purpose of the evaporator?
A) Reject heat
B) Absorb heat from the space being cooled ✅
C) Compress refrigerant
D) Store refrigerant
Q18. What is the function of a suction line accumulator?
A) To store liquid refrigerant and prevent it from reaching the compressor ✅
B) To increase refrigerant pressure
C) To filter dirt
D) To cool the condenser
2025/2026
COMPLETE QUESTIONS WITH CORRECT
DETAILED ANSWERS || 100%
GUARANTEED PASS BRAND NEW
VERSION
Description: This comprehensive revision set covers Refrigeration Fundamentals,
Refrigerants, Compressors, Condensers, Evaporators, Metering Devices, Electrical
Controls, Motors, System Troubleshooting, Load Calculations, Ductwork, Indoor
Air Quality, Heat Pumps, Chillers, and Safety Practices for HVAC mastery.
Key Words: HVAC, Refrigeration Cycle, Superheat, Subcooling, Compressor,
Condenser, Evaporator, TXV, PSI, BTU, Tonnage, Airflow, Thermostat, Heat Pump,
Troubleshooting, Safety
SECTION 1: REFRIGERATION FUNDAMENTALS (Q1–Q20)
Q1. What is the primary function of a refrigerant in an HVAC system?
A) To lubricate the compressor
B) To absorb and release heat during phase changes ✅
C) To filter contaminants from the air
D) To increase electrical conductivity
Q2. Which component in the refrigeration cycle is responsible for rejecting heat to the
outdoors?
A) Evaporator
,B) Compressor
C) Condenser ✅
D) Metering device
Q3. What is the unit of measurement for heat quantity in HVAC?
A) Pascal
B) BTU ✅
C) Ampere
D) Hertz
Q4. The refrigeration cycle begins at which component?
A) Condenser
B) Compressor ✅
C) Evaporator
D) Expansion valve
Q5. What does one ton of refrigeration equal in BTUs per hour?
A) 6,000
B) 10,000
C) 12,000 ✅
D) 15,000
Q6. Which law of thermodynamics states that heat flows from hot to cold?
A) First law
B) Second law ✅
C) Third law
D) Zeroth law
Q7. What is the state of refrigerant entering the compressor?
A) High-pressure liquid
B) Low-pressure superheated vapor ✅
C) Low-pressure liquid
D) High-pressure vapor
,Q8. Sensible heat is defined as:
A) Heat that changes the state of a substance
B) Heat that changes the temperature of a substance ✅
C) Heat that is lost through radiation
D) Heat that is generated electrically
Q9. Latent heat is best described as:
A) Heat that changes temperature
B) Heat that changes the state without changing temperature ✅
C) Heat that is measured in watts
D) Heat that is always lost
Q10. What is the boiling point of water at standard atmospheric pressure?
A) 32°F
B) 100°F
C) 212°F ✅
D) 273°F
Q11. Which of the following is a primary refrigerant?
A) R-134a ✅
B) Glycol
C) Brine
D) Water
Q12. What instrument measures the pressure in a refrigeration system?
A) Thermometer
B) Manifold gauge ✅
C) Multimeter
D) Anemometer
Q13. What does the term "superheat" refer to?
A) Heat added to liquid refrigerant
B) Heat added to vapor above its saturation point ✅
, C) Heat removed from vapor
D) Heat lost in the condenser
Q14. What does "subcooling" mean?
A) Cooling vapor below its saturation point
B) Cooling liquid below its saturation temperature ✅
C) Heating liquid above saturation
D) Cooling the compressor
Q15. Which of the following best describes a hermetic compressor?
A) A compressor that is open and belt-driven
B) A compressor sealed within a welded housing with the motor ✅
C) A compressor that uses no oil
D) A compressor that only works with water
Q16. What is the purpose of a receiver in a refrigeration system?
A) To store refrigerant liquid ✅
B) To compress refrigerant
C) To filter refrigerant
D) To measure refrigerant temperature
Q17. What is the primary purpose of the evaporator?
A) Reject heat
B) Absorb heat from the space being cooled ✅
C) Compress refrigerant
D) Store refrigerant
Q18. What is the function of a suction line accumulator?
A) To store liquid refrigerant and prevent it from reaching the compressor ✅
B) To increase refrigerant pressure
C) To filter dirt
D) To cool the condenser
