CALIFORNIA HVAC (C-20) CONTRACTOR EXAM | QUESTIONS AND
ANSWERS | VERIFIED ANSWERS PLUS RATIONALES | EXAM
ALREADY GRADED A+ | LATEST EXAM UPDATE
1. What does HVAC stand for?
A. Heating, Ventilation, and Air Conditioning
B. Heating, Vacuum, and Air Control
C. High Voltage Air Conditioning
D. Heat and Variable Cooling
Answer: A
Rationale: HVAC stands for Heating, Ventilation, and Air Conditioning, which are the core
functions of climate control systems.
2. Which component is responsible for removing heat from indoor air in a cooling system?
A. Furnace
B. Evaporator coil
C. Heat exchanger
D. Blower motor
Answer: B
Rationale: The evaporator coil absorbs heat from indoor air as refrigerant evaporates inside the
coil.
3. What refrigerant regulation governs handling of refrigerants in California?
A. OSHA Section 1926
B. EPA Section 608
C. NEC Article 430
D. Title 24 Part 6
Answer: B
Rationale: EPA Section 608 regulates refrigerant handling, certification, recovery, and
recycling requirements.
4. Which tool is used to measure superheat?
A. Micron gauge
B. Manifold gauge set and thermometer
C. Psychrometer
D. Anemometer
,Answer: B
Rationale: Superheat is calculated by measuring suction line temperature and pressure using
gauges and a thermometer.
5. What is the primary function of a thermostat?
A. Regulate refrigerant flow
B. Control electrical current
C. Maintain desired temperature
D. Measure humidity
Answer: C
Rationale: A thermostat senses room temperature and signals the HVAC system to maintain the
setpoint.
6. Which law relates pressure and temperature of a gas?
A. Ohm’s Law
B. Boyle’s Law
C. Dalton’s Law
D. Bernoulli’s Principle
Answer: B
Rationale: Boyle’s Law describes the inverse relationship between pressure and volume of a gas
at constant temperature.
7. What is the purpose of a capacitor in an HVAC motor?
A. Increase airflow
B. Store electrical energy to start/run motor
C. Regulate refrigerant
D. Measure voltage
Answer: B
Rationale: Capacitors provide a boost of stored electrical energy to help start and run motors
efficiently.
8. Which duct material has the highest fire resistance?
A. Flexible duct
B. Fiberboard duct
C. Sheet metal duct
D. Plastic duct
,Answer: C
Rationale: Sheet metal ducts provide the highest fire resistance compared to flexible or
fiberboard options.
9. What is the minimum SEER rating currently required for new AC units in California (as
regulated under California Title 24)?
A. 10
B. 13
C. 14
D. 15
Answer: D
Rationale: California energy efficiency standards require higher SEER ratings; 15 SEER meets
modern compliance requirements.
10. What device prevents backflow of combustion gases?
A. Draft inducer
B. Backdraft damper
C. Heat exchanger
D. Expansion valve
Answer: B
Rationale: A backdraft damper prevents combustion gases from re-entering the building.
11. What does AFUE measure?
A. Airflow efficiency
B. Cooling efficiency
C. Furnace efficiency
D. Compressor output
Answer: C
Rationale: AFUE (Annual Fuel Utilization Efficiency) measures furnace heating efficiency.
12. Which instrument measures relative humidity?
A. Hygrometer
B. Manometer
C. Micron gauge
D. Voltmeter
Answer: A
Rationale: A hygrometer measures moisture content in the air.
, 13. What is the purpose of a TXV valve?
A. Increase voltage
B. Control refrigerant flow
C. Measure airflow
D. Control blower speed
Answer: B
Rationale: A thermostatic expansion valve regulates refrigerant flow into the evaporator.
14. What is static pressure measured in?
A. Volts
B. PSI
C. Inches of water column
D. BTUs
Answer: C
Rationale: Static pressure in HVAC systems is measured in inches of water column.
15. What is the function of a heat exchanger?
A. Mix air and fuel
B. Transfer heat between mediums
C. Compress refrigerant
D. Control airflow
Answer: B
Rationale: A heat exchanger transfers heat without mixing combustion gases and indoor air.
16. Which code governs HVAC electrical installations?
A. UPC
B. NEC
C. IMC
D. OSHA
Answer: B
Rationale: The National Electrical Code (NEC) governs electrical wiring and installations.
17. What is R-value used to measure?
A. Airflow
B. Insulation effectiveness
C. Refrigerant pressure
D. Voltage resistance
ANSWERS | VERIFIED ANSWERS PLUS RATIONALES | EXAM
ALREADY GRADED A+ | LATEST EXAM UPDATE
1. What does HVAC stand for?
A. Heating, Ventilation, and Air Conditioning
B. Heating, Vacuum, and Air Control
C. High Voltage Air Conditioning
D. Heat and Variable Cooling
Answer: A
Rationale: HVAC stands for Heating, Ventilation, and Air Conditioning, which are the core
functions of climate control systems.
2. Which component is responsible for removing heat from indoor air in a cooling system?
A. Furnace
B. Evaporator coil
C. Heat exchanger
D. Blower motor
Answer: B
Rationale: The evaporator coil absorbs heat from indoor air as refrigerant evaporates inside the
coil.
3. What refrigerant regulation governs handling of refrigerants in California?
A. OSHA Section 1926
B. EPA Section 608
C. NEC Article 430
D. Title 24 Part 6
Answer: B
Rationale: EPA Section 608 regulates refrigerant handling, certification, recovery, and
recycling requirements.
4. Which tool is used to measure superheat?
A. Micron gauge
B. Manifold gauge set and thermometer
C. Psychrometer
D. Anemometer
,Answer: B
Rationale: Superheat is calculated by measuring suction line temperature and pressure using
gauges and a thermometer.
5. What is the primary function of a thermostat?
A. Regulate refrigerant flow
B. Control electrical current
C. Maintain desired temperature
D. Measure humidity
Answer: C
Rationale: A thermostat senses room temperature and signals the HVAC system to maintain the
setpoint.
6. Which law relates pressure and temperature of a gas?
A. Ohm’s Law
B. Boyle’s Law
C. Dalton’s Law
D. Bernoulli’s Principle
Answer: B
Rationale: Boyle’s Law describes the inverse relationship between pressure and volume of a gas
at constant temperature.
7. What is the purpose of a capacitor in an HVAC motor?
A. Increase airflow
B. Store electrical energy to start/run motor
C. Regulate refrigerant
D. Measure voltage
Answer: B
Rationale: Capacitors provide a boost of stored electrical energy to help start and run motors
efficiently.
8. Which duct material has the highest fire resistance?
A. Flexible duct
B. Fiberboard duct
C. Sheet metal duct
D. Plastic duct
,Answer: C
Rationale: Sheet metal ducts provide the highest fire resistance compared to flexible or
fiberboard options.
9. What is the minimum SEER rating currently required for new AC units in California (as
regulated under California Title 24)?
A. 10
B. 13
C. 14
D. 15
Answer: D
Rationale: California energy efficiency standards require higher SEER ratings; 15 SEER meets
modern compliance requirements.
10. What device prevents backflow of combustion gases?
A. Draft inducer
B. Backdraft damper
C. Heat exchanger
D. Expansion valve
Answer: B
Rationale: A backdraft damper prevents combustion gases from re-entering the building.
11. What does AFUE measure?
A. Airflow efficiency
B. Cooling efficiency
C. Furnace efficiency
D. Compressor output
Answer: C
Rationale: AFUE (Annual Fuel Utilization Efficiency) measures furnace heating efficiency.
12. Which instrument measures relative humidity?
A. Hygrometer
B. Manometer
C. Micron gauge
D. Voltmeter
Answer: A
Rationale: A hygrometer measures moisture content in the air.
, 13. What is the purpose of a TXV valve?
A. Increase voltage
B. Control refrigerant flow
C. Measure airflow
D. Control blower speed
Answer: B
Rationale: A thermostatic expansion valve regulates refrigerant flow into the evaporator.
14. What is static pressure measured in?
A. Volts
B. PSI
C. Inches of water column
D. BTUs
Answer: C
Rationale: Static pressure in HVAC systems is measured in inches of water column.
15. What is the function of a heat exchanger?
A. Mix air and fuel
B. Transfer heat between mediums
C. Compress refrigerant
D. Control airflow
Answer: B
Rationale: A heat exchanger transfers heat without mixing combustion gases and indoor air.
16. Which code governs HVAC electrical installations?
A. UPC
B. NEC
C. IMC
D. OSHA
Answer: B
Rationale: The National Electrical Code (NEC) governs electrical wiring and installations.
17. What is R-value used to measure?
A. Airflow
B. Insulation effectiveness
C. Refrigerant pressure
D. Voltage resistance
