HVAC Systems Final Examination (HVAC)
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1. Which component is responsible for removing moisture from the air in an
HVAC system?
A. Compressor
B. Evaporator coil
C. Condenser coil
D. Expansion valve
Answer: B ✔ Evaporator coil
The evaporator coil cools air below its dew point, causing condensation and
removing moisture.
2. What is the primary function of a thermostat in an HVAC system?
A. Increase refrigerant pressure
B. Regulate airflow velocity
C. Control temperature by cycling equipment
D. Filter airborne particles
Answer: C ✔ Control temperature by cycling equipment
A thermostat maintains setpoint temperature by turning heating or cooling
equipment on and off.
3. Which refrigerant property is most important for efficient heat transfer?
A. Low viscosity
, B. High odor
C. High color visibility
D. Electrical conductivity
Answer: A ✔ Low viscosity
Low viscosity improves flow efficiency and enhances heat exchange
performance.
4. What does SEER rating measure?
A. Sound efficiency of equipment
B. Seasonal energy efficiency of cooling systems
C. Structural endurance of compressors
D. Static energy of refrigerants
Answer: B ✔ Seasonal energy efficiency of cooling systems
SEER measures cooling output over a typical cooling season per energy input.
5. Which device protects the compressor from liquid refrigerant damage?
A. Accumulator
B. Blower motor
C. Expansion valve
D. Filter drier
Answer: A ✔ Accumulator
The accumulator prevents liquid slugging by ensuring only vapor enters the
compressor.
6. What is the purpose of a condenser in an HVAC system?
A. Absorb heat from indoor air
B. Remove dust particles
C. Reject heat to the outside environment
D. Compress refrigerant gas
Answer: C ✔ Reject heat to the outside environment
The condenser releases absorbed heat energy to outdoor air.
, 7. Which electrical component starts the compressor motor?
A. Relay
B. Capacitor
C. Thermocouple
D. Pressure switch
Answer: B ✔ Capacitor
A capacitor provides starting torque for compressor motors.
8. What is the most common cause of low airflow in HVAC systems?
A. Oversized condenser
B. Dirty air filter
C. High refrigerant charge
D. Faulty thermostat
Answer: B ✔ Dirty air filter
Clogged filters restrict airflow, reducing system efficiency.
9. What does a pressure switch in HVAC systems monitor?
A. Air humidity
B. Refrigerant pressure
C. Electrical voltage
D. Fan speed
Answer: B ✔ Refrigerant pressure
It protects the system from unsafe high or low pressure conditions.
10.Which gas law explains pressure-temperature relationship in HVAC
systems?
A. Boyle’s Law
B. Newton’s Law
C. Ohm’s Law
D. Pascal’s Law
, Answer: A ✔ Boyle’s Law
Boyle’s Law states pressure increases as volume decreases at constant
temperature.
11.What is the purpose of refrigerant in an HVAC system?
A. Lubricate moving parts
B. Transfer heat energy
C. Filter air contaminants
D. Increase air pressure
Answer: B ✔ Transfer heat energy
Refrigerants absorb and release heat through phase changes.
12.Which HVAC component removes solid particles from air?
A. Evaporator
B. Compressor
C. Air filter
D. Expansion valve
Answer: C ✔ Air filter
Filters capture dust, pollen, and debris from airflow.
13.What is superheat in refrigeration?
A. Heat added after condensation
B. Heat removed before compression
C. Temperature above boiling point after evaporation
D. Heat stored in condenser coil
Answer: C ✔ Temperature above boiling point after evaporation
Superheat ensures refrigerant is fully vaporized before entering compressor.
14.What is the function of an expansion valve?
A. Compress refrigerant
B. Increase refrigerant temperature
C. Reduce refrigerant pressure
D. Store refrigerant
Newest 2026-2027 Updated Practice
Exam | 200 Most Tested Questions &
Verified Detailed Answers | Tutor
Verified Success Bundle
1. Which component is responsible for removing moisture from the air in an
HVAC system?
A. Compressor
B. Evaporator coil
C. Condenser coil
D. Expansion valve
Answer: B ✔ Evaporator coil
The evaporator coil cools air below its dew point, causing condensation and
removing moisture.
2. What is the primary function of a thermostat in an HVAC system?
A. Increase refrigerant pressure
B. Regulate airflow velocity
C. Control temperature by cycling equipment
D. Filter airborne particles
Answer: C ✔ Control temperature by cycling equipment
A thermostat maintains setpoint temperature by turning heating or cooling
equipment on and off.
3. Which refrigerant property is most important for efficient heat transfer?
A. Low viscosity
, B. High odor
C. High color visibility
D. Electrical conductivity
Answer: A ✔ Low viscosity
Low viscosity improves flow efficiency and enhances heat exchange
performance.
4. What does SEER rating measure?
A. Sound efficiency of equipment
B. Seasonal energy efficiency of cooling systems
C. Structural endurance of compressors
D. Static energy of refrigerants
Answer: B ✔ Seasonal energy efficiency of cooling systems
SEER measures cooling output over a typical cooling season per energy input.
5. Which device protects the compressor from liquid refrigerant damage?
A. Accumulator
B. Blower motor
C. Expansion valve
D. Filter drier
Answer: A ✔ Accumulator
The accumulator prevents liquid slugging by ensuring only vapor enters the
compressor.
6. What is the purpose of a condenser in an HVAC system?
A. Absorb heat from indoor air
B. Remove dust particles
C. Reject heat to the outside environment
D. Compress refrigerant gas
Answer: C ✔ Reject heat to the outside environment
The condenser releases absorbed heat energy to outdoor air.
, 7. Which electrical component starts the compressor motor?
A. Relay
B. Capacitor
C. Thermocouple
D. Pressure switch
Answer: B ✔ Capacitor
A capacitor provides starting torque for compressor motors.
8. What is the most common cause of low airflow in HVAC systems?
A. Oversized condenser
B. Dirty air filter
C. High refrigerant charge
D. Faulty thermostat
Answer: B ✔ Dirty air filter
Clogged filters restrict airflow, reducing system efficiency.
9. What does a pressure switch in HVAC systems monitor?
A. Air humidity
B. Refrigerant pressure
C. Electrical voltage
D. Fan speed
Answer: B ✔ Refrigerant pressure
It protects the system from unsafe high or low pressure conditions.
10.Which gas law explains pressure-temperature relationship in HVAC
systems?
A. Boyle’s Law
B. Newton’s Law
C. Ohm’s Law
D. Pascal’s Law
, Answer: A ✔ Boyle’s Law
Boyle’s Law states pressure increases as volume decreases at constant
temperature.
11.What is the purpose of refrigerant in an HVAC system?
A. Lubricate moving parts
B. Transfer heat energy
C. Filter air contaminants
D. Increase air pressure
Answer: B ✔ Transfer heat energy
Refrigerants absorb and release heat through phase changes.
12.Which HVAC component removes solid particles from air?
A. Evaporator
B. Compressor
C. Air filter
D. Expansion valve
Answer: C ✔ Air filter
Filters capture dust, pollen, and debris from airflow.
13.What is superheat in refrigeration?
A. Heat added after condensation
B. Heat removed before compression
C. Temperature above boiling point after evaporation
D. Heat stored in condenser coil
Answer: C ✔ Temperature above boiling point after evaporation
Superheat ensures refrigerant is fully vaporized before entering compressor.
14.What is the function of an expansion valve?
A. Compress refrigerant
B. Increase refrigerant temperature
C. Reduce refrigerant pressure
D. Store refrigerant
