Missouri HVAC Master License Exam —
Columbia Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. What is the primary purpose of a heat pump in HVAC systems?
A. Generate electricity
B. Move heat from one location to another
C. Produce combustion gases
D. Increase humidity
B. Move heat from one location to another
A heat pump transfers heat between indoor and outdoor environments
depending on the mode of operation.
2. Which refrigerant property is most important for efficient heat
transfer?
A. High toxicity
, B. Low boiling point
C. High color visibility
D. High viscosity
B. Low boiling point
A low boiling point allows refrigerant to evaporate and absorb heat
efficiently at low temperatures.
3. What device removes moisture from air in an HVAC system?
A. Compressor
B. Evaporator coil
C. Expansion valve
D. Condenser fan
B. Evaporator coil
Moisture condenses on the cold evaporator coil as air passes over it,
removing humidity.
4. Which law explains the relationship between pressure and
temperature in a sealed system?
A. Ohm’s Law
B. Boyle’s Law
C. Newton’s Law
D. Dalton’s Law
,B. Boyle’s Law
Boyle’s Law states that pressure increases as volume decreases at constant
temperature.
5. What is the function of the compressor in a refrigeration cycle?
A. Expand refrigerant
B. Cool air
C. Raise refrigerant pressure and temperature
D. Remove moisture
C. Raise refrigerant pressure and temperature
The compressor circulates refrigerant and increases its pressure and
temperature.
6. Which component meters refrigerant into the evaporator?
A. Condenser
B. Expansion valve
C. Compressor
D. Accumulator
B. Expansion valve
The expansion valve controls refrigerant flow and reduces pressure before
the evaporator.
7. What does SEER rating measure?
A. Sound level efficiency
, B. Seasonal energy efficiency ratio
C. Static electrical resistance
D. System exhaust emissions
B. Seasonal energy efficiency ratio
SEER measures cooling output over a typical cooling season divided by
energy input.
8. Which gas is commonly used for brazing safety purge?
A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Argon only
B. Nitrogen
Nitrogen is used to prevent oxidation inside piping during brazing.
9. What is the standard voltage for most residential HVAC systems in the
U.S.?
A. 120V only
B. 24V only
C. 240V
D. 480V
Columbia Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a heat pump in HVAC systems?
A. Generate electricity
B. Move heat from one location to another
C. Produce combustion gases
D. Increase humidity
B. Move heat from one location to another
A heat pump transfers heat between indoor and outdoor environments
depending on the mode of operation.
2. Which refrigerant property is most important for efficient heat
transfer?
A. High toxicity
, B. Low boiling point
C. High color visibility
D. High viscosity
B. Low boiling point
A low boiling point allows refrigerant to evaporate and absorb heat
efficiently at low temperatures.
3. What device removes moisture from air in an HVAC system?
A. Compressor
B. Evaporator coil
C. Expansion valve
D. Condenser fan
B. Evaporator coil
Moisture condenses on the cold evaporator coil as air passes over it,
removing humidity.
4. Which law explains the relationship between pressure and
temperature in a sealed system?
A. Ohm’s Law
B. Boyle’s Law
C. Newton’s Law
D. Dalton’s Law
,B. Boyle’s Law
Boyle’s Law states that pressure increases as volume decreases at constant
temperature.
5. What is the function of the compressor in a refrigeration cycle?
A. Expand refrigerant
B. Cool air
C. Raise refrigerant pressure and temperature
D. Remove moisture
C. Raise refrigerant pressure and temperature
The compressor circulates refrigerant and increases its pressure and
temperature.
6. Which component meters refrigerant into the evaporator?
A. Condenser
B. Expansion valve
C. Compressor
D. Accumulator
B. Expansion valve
The expansion valve controls refrigerant flow and reduces pressure before
the evaporator.
7. What does SEER rating measure?
A. Sound level efficiency
, B. Seasonal energy efficiency ratio
C. Static electrical resistance
D. System exhaust emissions
B. Seasonal energy efficiency ratio
SEER measures cooling output over a typical cooling season divided by
energy input.
8. Which gas is commonly used for brazing safety purge?
A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Argon only
B. Nitrogen
Nitrogen is used to prevent oxidation inside piping during brazing.
9. What is the standard voltage for most residential HVAC systems in the
U.S.?
A. 120V only
B. 24V only
C. 240V
D. 480V
