TEXAS AIR CONDITIONING CONTRACTOR EXAM
1. What is the primary purpose of a refrigerant in an air
conditioning system?
A. To increase air pressure
B. To absorb and release heat
C. To filter air contaminants
D. To lubricate the compressor
Answer: B
Rationale: Refrigerant is used to transfer heat by absorbing
it at low pressure and releasing it at high pressure during
phase changes.
2. Which component starts and stops the compressor based
on temperature settings?
A. Expansion valve
B. Thermostat
C. Condenser coil
D. Evaporator fan
Answer: B
Rationale: The thermostat senses room temperature and
signals the system to start or stop cooling.
3. What is the function of the condenser coil?
A. Absorb heat from indoor air
B. Release heat to outdoor air
C. Measure refrigerant pressure
D. Filter moisture from air
Answer: B
Rationale: The condenser coil releases heat absorbed from
inside the building to the outside environment.
,4. What does a low refrigerant charge typically cause?
A. Increased cooling efficiency
B. Reduced system pressure and poor cooling
C. Higher indoor humidity only
D. Compressor lubrication improvement
Answer: B
Rationale: Low refrigerant reduces system pressure and
heat transfer, resulting in poor cooling performance.
5. Which tool is used to measure electrical current in HVAC
systems?
A. Manometer
B. Thermometer
C. Clamp meter
D. Psychrometer
Answer: C
Rationale: A clamp meter measures current flow without
disconnecting the circuit.
6. What is the purpose of the evaporator coil?
A. To release heat outdoors
B. To compress refrigerant
C. To absorb heat from indoor air
D. To regulate voltage
Answer: C
Rationale: The evaporator coil absorbs heat from indoor
air, cooling it.
7. Which refrigerant was commonly phased out due to
environmental concerns?
A. R-410A
B. R-134a
, C. R-22
D. R-32
Answer: C
Rationale: R-22 was phased out because it damages the
ozone layer.
8. What device controls refrigerant flow into the evaporator?
A. Compressor
B. Expansion valve
C. Blower motor
D. Capacitor
Answer: B
Rationale: The expansion valve meters refrigerant into the
evaporator coil.
9. What is superheat?
A. Refrigerant below freezing point
B. Heat removed from condenser
C. Temperature of refrigerant above boiling point
D. Air temperature inside duct
Answer: C
Rationale: Superheat is the temperature increase of vapor
refrigerant after it has completely evaporated.
10. What is the purpose of a capacitor in an HVAC
system?
A. Store refrigerant
B. Start and run motors
C. Measure airflow
D. Clean air filters
Answer: B
1. What is the primary purpose of a refrigerant in an air
conditioning system?
A. To increase air pressure
B. To absorb and release heat
C. To filter air contaminants
D. To lubricate the compressor
Answer: B
Rationale: Refrigerant is used to transfer heat by absorbing
it at low pressure and releasing it at high pressure during
phase changes.
2. Which component starts and stops the compressor based
on temperature settings?
A. Expansion valve
B. Thermostat
C. Condenser coil
D. Evaporator fan
Answer: B
Rationale: The thermostat senses room temperature and
signals the system to start or stop cooling.
3. What is the function of the condenser coil?
A. Absorb heat from indoor air
B. Release heat to outdoor air
C. Measure refrigerant pressure
D. Filter moisture from air
Answer: B
Rationale: The condenser coil releases heat absorbed from
inside the building to the outside environment.
,4. What does a low refrigerant charge typically cause?
A. Increased cooling efficiency
B. Reduced system pressure and poor cooling
C. Higher indoor humidity only
D. Compressor lubrication improvement
Answer: B
Rationale: Low refrigerant reduces system pressure and
heat transfer, resulting in poor cooling performance.
5. Which tool is used to measure electrical current in HVAC
systems?
A. Manometer
B. Thermometer
C. Clamp meter
D. Psychrometer
Answer: C
Rationale: A clamp meter measures current flow without
disconnecting the circuit.
6. What is the purpose of the evaporator coil?
A. To release heat outdoors
B. To compress refrigerant
C. To absorb heat from indoor air
D. To regulate voltage
Answer: C
Rationale: The evaporator coil absorbs heat from indoor
air, cooling it.
7. Which refrigerant was commonly phased out due to
environmental concerns?
A. R-410A
B. R-134a
, C. R-22
D. R-32
Answer: C
Rationale: R-22 was phased out because it damages the
ozone layer.
8. What device controls refrigerant flow into the evaporator?
A. Compressor
B. Expansion valve
C. Blower motor
D. Capacitor
Answer: B
Rationale: The expansion valve meters refrigerant into the
evaporator coil.
9. What is superheat?
A. Refrigerant below freezing point
B. Heat removed from condenser
C. Temperature of refrigerant above boiling point
D. Air temperature inside duct
Answer: C
Rationale: Superheat is the temperature increase of vapor
refrigerant after it has completely evaporated.
10. What is the purpose of a capacitor in an HVAC
system?
A. Store refrigerant
B. Start and run motors
C. Measure airflow
D. Clean air filters
Answer: B
