HVAC Maintenance Technician Practice
Exam Questions With Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of an air filter in an HVAC system?
A. Increase refrigerant pressure
B. Remove contaminants from air
C. Cool the condenser coil
D. Lubricate moving parts
Correct Answer: B
Rationale: Air filters trap dust, debris, and airborne particles to improve
indoor air quality and protect system components.
2. Which refrigerant is commonly used in modern residential systems?
A. R-22
B. R-410A
C. Ammonia
D. R-12
Correct Answer: B
Rationale: R-410A is widely used in newer systems due to its efficiency
and lower environmental impact.
,3. What does a thermostat control?
A. Refrigerant flow
B. Air humidity only
C. Temperature of indoor space
D. Compressor oil level
Correct Answer: C
Rationale: A thermostat regulates indoor temperature by controlling
HVAC system operation.
4. What tool is used to measure electrical current in HVAC systems?
A. Manometer
B. Clamp meter
C. Thermometer
D. Psychrometer
Correct Answer: B
Rationale: A clamp meter measures current without breaking the circuit.
5. What is the function of a capacitor in an HVAC system?
A. Store refrigerant
B. Start and run motors
C. Filter air
D. Heat air
Correct Answer: B
Rationale: Capacitors provide electrical energy to start and run
compressor and fan motors.
,6. What does superheat indicate?
A. Liquid refrigerant temperature
B. Gas temperature above boiling point
C. Coil cleanliness
D. Electrical resistance
Correct Answer: B
Rationale: Superheat measures how much refrigerant vapor is heated
above its boiling point.
7. What is the purpose of a contactor?
A. Measure pressure
B. Control electrical flow to components
C. Filter refrigerant
D. Increase airflow
Correct Answer: B
Rationale: A contactor switches electrical power to major HVAC
components.
8. Which component removes moisture from refrigerant?
A. Compressor
B. Evaporator
C. Filter drier
D. Expansion valve
, Correct Answer: C
Rationale: A filter drier absorbs moisture and contaminants in the
refrigerant system.
9. What is the main function of the compressor?
A. Cool air
B. Increase refrigerant pressure
C. Filter air
D. Measure humidity
Correct Answer: B
Rationale: The compressor pressurizes refrigerant and circulates it
through the system.
10. What does a clogged air filter cause?
A. Higher airflow
B. Reduced airflow
C. Lower refrigerant pressure
D. Increased humidity
Correct Answer: B
Rationale: A clogged filter restricts airflow, reducing system efficiency.
11. What is used to check refrigerant leaks?
A. Multimeter
B. Leak detector
Exam Questions With Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of an air filter in an HVAC system?
A. Increase refrigerant pressure
B. Remove contaminants from air
C. Cool the condenser coil
D. Lubricate moving parts
Correct Answer: B
Rationale: Air filters trap dust, debris, and airborne particles to improve
indoor air quality and protect system components.
2. Which refrigerant is commonly used in modern residential systems?
A. R-22
B. R-410A
C. Ammonia
D. R-12
Correct Answer: B
Rationale: R-410A is widely used in newer systems due to its efficiency
and lower environmental impact.
,3. What does a thermostat control?
A. Refrigerant flow
B. Air humidity only
C. Temperature of indoor space
D. Compressor oil level
Correct Answer: C
Rationale: A thermostat regulates indoor temperature by controlling
HVAC system operation.
4. What tool is used to measure electrical current in HVAC systems?
A. Manometer
B. Clamp meter
C. Thermometer
D. Psychrometer
Correct Answer: B
Rationale: A clamp meter measures current without breaking the circuit.
5. What is the function of a capacitor in an HVAC system?
A. Store refrigerant
B. Start and run motors
C. Filter air
D. Heat air
Correct Answer: B
Rationale: Capacitors provide electrical energy to start and run
compressor and fan motors.
,6. What does superheat indicate?
A. Liquid refrigerant temperature
B. Gas temperature above boiling point
C. Coil cleanliness
D. Electrical resistance
Correct Answer: B
Rationale: Superheat measures how much refrigerant vapor is heated
above its boiling point.
7. What is the purpose of a contactor?
A. Measure pressure
B. Control electrical flow to components
C. Filter refrigerant
D. Increase airflow
Correct Answer: B
Rationale: A contactor switches electrical power to major HVAC
components.
8. Which component removes moisture from refrigerant?
A. Compressor
B. Evaporator
C. Filter drier
D. Expansion valve
, Correct Answer: C
Rationale: A filter drier absorbs moisture and contaminants in the
refrigerant system.
9. What is the main function of the compressor?
A. Cool air
B. Increase refrigerant pressure
C. Filter air
D. Measure humidity
Correct Answer: B
Rationale: The compressor pressurizes refrigerant and circulates it
through the system.
10. What does a clogged air filter cause?
A. Higher airflow
B. Reduced airflow
C. Lower refrigerant pressure
D. Increased humidity
Correct Answer: B
Rationale: A clogged filter restricts airflow, reducing system efficiency.
11. What is used to check refrigerant leaks?
A. Multimeter
B. Leak detector
