HVAC Excellence Master Specialist
Certification Practice Exam 100
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
1. What is the primary purpose of a compressor in a refrigeration system?
A) To absorb heat from the conditioned space
B) To raise the pressure and temperature of refrigerant vapor
C) To condense refrigerant vapor into liquid
D) To meter refrigerant into the evaporator
Rationale: The compressor raises refrigerant vapor pressure and temperature
so it can reject heat in the condenser. It does not absorb heat, condense
refrigerant, or meter flow.
2. What is the boiling point of R-410A at 118 psig?
A) 32°F
B) 40°F
C) 50°F
D) 60°F
Rationale: At 118 psig, R-410A saturates at approximately 40°F, which
corresponds to a typical evaporator operating temperature for comfort
cooling.
3. Which type of compressor is most commonly used in residential split air
conditioning systems?
A) Reciprocating or scroll
B) Centrifugal
,C) Screw
D) Rotary vane only
Rationale: Residential split systems typically use hermetic reciprocating or
scroll compressors due to their reliability and efficiency in small to medium
capacities.
4. What is the function of the accumulator in a refrigeration system?
A) Store liquid refrigerant for the condenser
B) Prevent liquid refrigerant from entering the compressor
C) Increase refrigerant subcooling
D) Reduce refrigerant superheat at the evaporator
Rationale: The accumulator traps liquid refrigerant and allows only vapor to
return to the compressor, preventing slugging and compressor damage.
5. Superheat is defined as:
A) The temperature difference between the condenser and evaporator
B) The temperature of vapor above its saturation temperature
C) The temperature difference between liquid line and suction line
D) The heat added to refrigerant in the condenser
Rationale: Superheat is the amount of heat added to refrigerant vapor above
its saturation point, ensuring no liquid enters the compressor.
6. What is the normal superheat range for a TXV system?
A) 8°F to 12°F
B) 15°F to 20°F
C) 20°F to 25°F
D) 0°F to 5°F
Rationale: A TXV system is typically charged to 8°F to 12°F superheat at the
evaporator outlet for proper operation.
7. Subcooling is defined as:
A) The temperature of liquid below its saturation temperature
B) The temperature of vapor above its saturation temperature
C) The heat removed from vapor in the evaporator
D) The pressure drop across the metering device
, Rationale: Subcooling is the amount of heat removed from liquid refrigerant
below its saturation temperature, typically measured at the condenser outlet.
8. What is the normal subcooling range for a TXV system?
A) 2°F to 4°F
B) 8°F to 12°F
C) 15°F to 20°F
D) 20°F to 25°F
Rationale: A properly charged TXV system typically has 8°F to 12°F subcooling
at the condenser outlet.
9. Which component controls the flow of refrigerant into the evaporator?
A) Compressor
B) Condenser
C) Thermostatic expansion valve
D) Accumulator
Rationale: The TXV meters refrigerant into the evaporator and maintains
proper superheat by modulating flow based on evaporator load.
10. What is the purpose of the condenser in a refrigeration system?
A) Absorb heat from the space
B) Reject heat from the refrigerant to the outdoor air
C) Meter refrigerant
D) Compress refrigerant vapor
Rationale: The condenser rejects heat absorbed by the refrigerant in the
evaporator plus compressor heat to the outdoor air, condensing vapor to
liquid.
11. What is the typical condensing temperature for an air-cooled condenser
on a design day?
A) 85°F
B) 95°F
C) 115°F to 125°F
D) 140°F to 150°F
Certification Practice Exam 100
Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
1. What is the primary purpose of a compressor in a refrigeration system?
A) To absorb heat from the conditioned space
B) To raise the pressure and temperature of refrigerant vapor
C) To condense refrigerant vapor into liquid
D) To meter refrigerant into the evaporator
Rationale: The compressor raises refrigerant vapor pressure and temperature
so it can reject heat in the condenser. It does not absorb heat, condense
refrigerant, or meter flow.
2. What is the boiling point of R-410A at 118 psig?
A) 32°F
B) 40°F
C) 50°F
D) 60°F
Rationale: At 118 psig, R-410A saturates at approximately 40°F, which
corresponds to a typical evaporator operating temperature for comfort
cooling.
3. Which type of compressor is most commonly used in residential split air
conditioning systems?
A) Reciprocating or scroll
B) Centrifugal
,C) Screw
D) Rotary vane only
Rationale: Residential split systems typically use hermetic reciprocating or
scroll compressors due to their reliability and efficiency in small to medium
capacities.
4. What is the function of the accumulator in a refrigeration system?
A) Store liquid refrigerant for the condenser
B) Prevent liquid refrigerant from entering the compressor
C) Increase refrigerant subcooling
D) Reduce refrigerant superheat at the evaporator
Rationale: The accumulator traps liquid refrigerant and allows only vapor to
return to the compressor, preventing slugging and compressor damage.
5. Superheat is defined as:
A) The temperature difference between the condenser and evaporator
B) The temperature of vapor above its saturation temperature
C) The temperature difference between liquid line and suction line
D) The heat added to refrigerant in the condenser
Rationale: Superheat is the amount of heat added to refrigerant vapor above
its saturation point, ensuring no liquid enters the compressor.
6. What is the normal superheat range for a TXV system?
A) 8°F to 12°F
B) 15°F to 20°F
C) 20°F to 25°F
D) 0°F to 5°F
Rationale: A TXV system is typically charged to 8°F to 12°F superheat at the
evaporator outlet for proper operation.
7. Subcooling is defined as:
A) The temperature of liquid below its saturation temperature
B) The temperature of vapor above its saturation temperature
C) The heat removed from vapor in the evaporator
D) The pressure drop across the metering device
, Rationale: Subcooling is the amount of heat removed from liquid refrigerant
below its saturation temperature, typically measured at the condenser outlet.
8. What is the normal subcooling range for a TXV system?
A) 2°F to 4°F
B) 8°F to 12°F
C) 15°F to 20°F
D) 20°F to 25°F
Rationale: A properly charged TXV system typically has 8°F to 12°F subcooling
at the condenser outlet.
9. Which component controls the flow of refrigerant into the evaporator?
A) Compressor
B) Condenser
C) Thermostatic expansion valve
D) Accumulator
Rationale: The TXV meters refrigerant into the evaporator and maintains
proper superheat by modulating flow based on evaporator load.
10. What is the purpose of the condenser in a refrigeration system?
A) Absorb heat from the space
B) Reject heat from the refrigerant to the outdoor air
C) Meter refrigerant
D) Compress refrigerant vapor
Rationale: The condenser rejects heat absorbed by the refrigerant in the
evaporator plus compressor heat to the outdoor air, condensing vapor to
liquid.
11. What is the typical condensing temperature for an air-cooled condenser
on a design day?
A) 85°F
B) 95°F
C) 115°F to 125°F
D) 140°F to 150°F
