TEXAS HVAC TECHNICIAN CERTIFICATION
1. What is the primary purpose of refrigerant in an HVAC
system?
A. To filter air contaminants
B. To absorb and release heat
C. To lubricate compressor parts
D. To increase electrical efficiency
Correct answer: B
Rationale: Refrigerant’s main function is to transfer heat by
absorbing it at low pressure/temperature in the evaporator and
releasing it at high pressure/temperature in the condenser.
2. Which tool is used to measure electrical resistance?
A. Manometer
B. Thermometer
C. Ohmmeter
D. Anemometer
Correct answer: C
Rationale: An ohmmeter measures electrical resistance in ohms
and is commonly used to test continuity in HVAC components.
3. What does superheat refer to?
A. Refrigerant below boiling point
B. Refrigerant above boiling point after evaporation
C. Air temperature in the condenser
D. Compressor discharge temperature only
Correct answer: B
Rationale: Superheat is the temperature of vapor refrigerant
,above its saturation (boiling) temperature after it has fully
evaporated.
4. What is the function of a thermostat in an HVAC system?
A. Increase refrigerant pressure
B. Control system temperature by switching equipment on and
off
C. Filter indoor air
D. Store electrical energy
Correct answer: B
Rationale: A thermostat senses indoor temperature and
controls HVAC operation to maintain the setpoint.
5. Which refrigerant is commonly used in modern residential
HVAC systems?
A. R-22
B. R-12
C. R-410A
D. Ammonia
Correct answer: C
Rationale: R-410A is widely used in newer systems due to its
higher efficiency and lower ozone depletion potential compared
to R-22.
6. What component removes moisture and contaminants
from refrigerant?
A. Compressor
B. Expansion valve
,C. Filter drier
D. Evaporator coil
Correct answer: C
Rationale: A filter drier removes moisture and debris to protect
system components.
7. What is the primary function of the compressor?
A. Cool indoor air
B. Increase refrigerant pressure and temperature
C. Remove humidity
D. Filter air
Correct answer: B
Rationale: The compressor raises refrigerant pressure and
temperature to allow heat rejection in the condenser.
8. What unit measures airflow in HVAC systems?
A. PSI
B. BTU
C. CFM
D. Ohms
Correct answer: C
Rationale: CFM (cubic feet per minute) measures the volume of
air moving through a system.
9. What does latent heat refer to?
A. Heat that changes air pressure
B. Heat required to change state without temperature change
C. Heat generated by electrical resistance
D. Heat measured in BTUs only
, Correct answer: B
Rationale: Latent heat is energy involved in phase changes, such
as liquid to vapor.
10. Which safety device prevents excessive system pressure?
A. Thermostat
B. Pressure relief valve
C. Expansion valve
D. Capacitor
Correct answer: B
Rationale: A pressure relief valve releases excess pressure to
prevent equipment damage.
11. What does a capacitor do in an HVAC motor circuit?
A. Stores refrigerant
B. Increases airflow
C. Provides a phase shift for motor starting
D. Filters electricity
Correct answer: C
Rationale: Capacitors help start or run motors by creating a
phase difference in electrical current.
12. Which gas is commonly used for leak detection?
A. Oxygen
B. Nitrogen
C. Helium
D. Argon
1. What is the primary purpose of refrigerant in an HVAC
system?
A. To filter air contaminants
B. To absorb and release heat
C. To lubricate compressor parts
D. To increase electrical efficiency
Correct answer: B
Rationale: Refrigerant’s main function is to transfer heat by
absorbing it at low pressure/temperature in the evaporator and
releasing it at high pressure/temperature in the condenser.
2. Which tool is used to measure electrical resistance?
A. Manometer
B. Thermometer
C. Ohmmeter
D. Anemometer
Correct answer: C
Rationale: An ohmmeter measures electrical resistance in ohms
and is commonly used to test continuity in HVAC components.
3. What does superheat refer to?
A. Refrigerant below boiling point
B. Refrigerant above boiling point after evaporation
C. Air temperature in the condenser
D. Compressor discharge temperature only
Correct answer: B
Rationale: Superheat is the temperature of vapor refrigerant
,above its saturation (boiling) temperature after it has fully
evaporated.
4. What is the function of a thermostat in an HVAC system?
A. Increase refrigerant pressure
B. Control system temperature by switching equipment on and
off
C. Filter indoor air
D. Store electrical energy
Correct answer: B
Rationale: A thermostat senses indoor temperature and
controls HVAC operation to maintain the setpoint.
5. Which refrigerant is commonly used in modern residential
HVAC systems?
A. R-22
B. R-12
C. R-410A
D. Ammonia
Correct answer: C
Rationale: R-410A is widely used in newer systems due to its
higher efficiency and lower ozone depletion potential compared
to R-22.
6. What component removes moisture and contaminants
from refrigerant?
A. Compressor
B. Expansion valve
,C. Filter drier
D. Evaporator coil
Correct answer: C
Rationale: A filter drier removes moisture and debris to protect
system components.
7. What is the primary function of the compressor?
A. Cool indoor air
B. Increase refrigerant pressure and temperature
C. Remove humidity
D. Filter air
Correct answer: B
Rationale: The compressor raises refrigerant pressure and
temperature to allow heat rejection in the condenser.
8. What unit measures airflow in HVAC systems?
A. PSI
B. BTU
C. CFM
D. Ohms
Correct answer: C
Rationale: CFM (cubic feet per minute) measures the volume of
air moving through a system.
9. What does latent heat refer to?
A. Heat that changes air pressure
B. Heat required to change state without temperature change
C. Heat generated by electrical resistance
D. Heat measured in BTUs only
, Correct answer: B
Rationale: Latent heat is energy involved in phase changes, such
as liquid to vapor.
10. Which safety device prevents excessive system pressure?
A. Thermostat
B. Pressure relief valve
C. Expansion valve
D. Capacitor
Correct answer: B
Rationale: A pressure relief valve releases excess pressure to
prevent equipment damage.
11. What does a capacitor do in an HVAC motor circuit?
A. Stores refrigerant
B. Increases airflow
C. Provides a phase shift for motor starting
D. Filters electricity
Correct answer: C
Rationale: Capacitors help start or run motors by creating a
phase difference in electrical current.
12. Which gas is commonly used for leak detection?
A. Oxygen
B. Nitrogen
C. Helium
D. Argon
