HVAC Contractor Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2025|2026 Q&A | Instant
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1. What does the acronym HVAC stand for?
a) Heat, Ventilation, and Cooling
b) Heating, Ventilation, and Climate
c) Heating, Ventilation, and Air Conditioning
d) Humidity, Ventilation, and Air Circulation
The industry term HVAC refers specifically to Heating, Ventilation, and
Air Conditioning systems.
2. Which refrigerant is being phased out due to ozone depletion
concerns?
a) R-410A
b) R-22
c) R-134a
, d) R-407C
R-22 (Freon) is being phased out globally due to its ozone-depleting
properties.
3. What is the purpose of a thermostat in an HVAC system?
a) To increase humidity
b) To circulate refrigerant
c) To control temperature
d) To reduce noise
The thermostat regulates indoor temperature by signaling the HVAC
system to heat or cool.
4. Which type of current is most commonly used in residential HVAC
systems in the U.S.?
a) Direct current (DC)
b) Alternating current (AC)
c) Three-phase DC
d) Two-phase AC
Residential systems typically use single-phase alternating current (AC).
5. What device removes moisture from the air in an HVAC system?
a) Condenser coil
b) Evaporator coil
c) Expansion valve
d) Blower motor
, As warm air passes over the evaporator coil, it cools and moisture
condenses, dehumidifying the air.
6. What is the primary purpose of ductwork in HVAC systems?
a) Insulate the building
b) Provide structural support
c) Distribute conditioned air
d) Store refrigerant
Ductwork delivers heated or cooled air throughout the building.
7. Which component compresses refrigerant gas?
a) Evaporator
b) Condenser
c) Compressor
d) Expansion valve
The compressor raises refrigerant pressure and temperature, moving it
through the system.
8. Which tool measures refrigerant pressure?
a) Anemometer
b) Thermocouple
c) Manifold gauge set
d) Hygrometer
Manifold gauges are used to measure refrigerant pressures during
servicing.
, 9. Which gas law explains the relationship between pressure and volume
in refrigerants?
a) Charles’ Law
b) Boyle’s Law
c) Dalton’s Law
d) Henry’s Law
Boyle’s Law states that pressure and volume are inversely proportional
at constant temperature.
10. What is SEER a rating of?
a) Humidity removal
b) Air distribution
c) Cooling efficiency
d) Heating capacity
SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency
over a season.
11. What is the typical voltage for residential HVAC control circuits?
a) 120V
b) 24V
c) 48V
d) 240V
Most thermostats and control systems run on 24V supplied by a
transformer.
And Correct Answers (Verified Answers)
Plus Rationales 2025|2026 Q&A | Instant
Download Pdf
1. What does the acronym HVAC stand for?
a) Heat, Ventilation, and Cooling
b) Heating, Ventilation, and Climate
c) Heating, Ventilation, and Air Conditioning
d) Humidity, Ventilation, and Air Circulation
The industry term HVAC refers specifically to Heating, Ventilation, and
Air Conditioning systems.
2. Which refrigerant is being phased out due to ozone depletion
concerns?
a) R-410A
b) R-22
c) R-134a
, d) R-407C
R-22 (Freon) is being phased out globally due to its ozone-depleting
properties.
3. What is the purpose of a thermostat in an HVAC system?
a) To increase humidity
b) To circulate refrigerant
c) To control temperature
d) To reduce noise
The thermostat regulates indoor temperature by signaling the HVAC
system to heat or cool.
4. Which type of current is most commonly used in residential HVAC
systems in the U.S.?
a) Direct current (DC)
b) Alternating current (AC)
c) Three-phase DC
d) Two-phase AC
Residential systems typically use single-phase alternating current (AC).
5. What device removes moisture from the air in an HVAC system?
a) Condenser coil
b) Evaporator coil
c) Expansion valve
d) Blower motor
, As warm air passes over the evaporator coil, it cools and moisture
condenses, dehumidifying the air.
6. What is the primary purpose of ductwork in HVAC systems?
a) Insulate the building
b) Provide structural support
c) Distribute conditioned air
d) Store refrigerant
Ductwork delivers heated or cooled air throughout the building.
7. Which component compresses refrigerant gas?
a) Evaporator
b) Condenser
c) Compressor
d) Expansion valve
The compressor raises refrigerant pressure and temperature, moving it
through the system.
8. Which tool measures refrigerant pressure?
a) Anemometer
b) Thermocouple
c) Manifold gauge set
d) Hygrometer
Manifold gauges are used to measure refrigerant pressures during
servicing.
, 9. Which gas law explains the relationship between pressure and volume
in refrigerants?
a) Charles’ Law
b) Boyle’s Law
c) Dalton’s Law
d) Henry’s Law
Boyle’s Law states that pressure and volume are inversely proportional
at constant temperature.
10. What is SEER a rating of?
a) Humidity removal
b) Air distribution
c) Cooling efficiency
d) Heating capacity
SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency
over a season.
11. What is the typical voltage for residential HVAC control circuits?
a) 120V
b) 24V
c) 48V
d) 240V
Most thermostats and control systems run on 24V supplied by a
transformer.
