HVAC Excellence Professional
Technician Certification Practice Exam
100 Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
1. Which of the following is the primary function of the evaporator coil in a
refrigeration system?
A. Reject heat to the outdoors
B. Absorb heat from the conditioned space
C. Compress refrigerant vapor
D. Meter refrigerant flow
Rationale: The evaporator coil absorbs heat from the air passing over
it, cooling the space and evaporating the refrigerant.
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 boils at approximately 40°F, which is a
common suction pressure for comfort cooling.
3. Which tool is used to measure the superheat of a system?
A. Manifold gauge only
B. Volt-ohm meter
C. Thermistor thermometer and manifold gauge
D. Vacuum gauge
Rationale: Superheat requires both suction pressure (converted to
saturation temperature) and suction line temperature.
,4. What is the acceptable range for superheat on a fixed orifice system?
A. 0–5°F
B. 5–15°F
C. 15–25°F
D. 25–35°F
Rationale: Fixed orifice systems typically require 5–15°F superheat for
proper operation.
5. Which refrigerant is classified as A1 (non-toxic, non-flammable)?
A. R-22
B. R-410A
C. R-32
D. R-1234yf
Rationale: R-410A is an A1 refrigerant, meaning low toxicity and no
flame propagation.
6. What does a compressor's service valve in the back-seated position do?
A. Allows access to the system
B. Isolates the compressor from the system
C. Bypasses the metering device
D. Opens the liquid line
Rationale: Back-seating the service valve closes the access port and
isolates the compressor from the system.
7. Which component controls the flow of refrigerant into the evaporator?
A. Compressor
B. Condenser
C. Metering device
D. Accumulator
Rationale: The metering device regulates refrigerant flow into the
evaporator.
8. What is the primary purpose of a condenser?
A. Absorb heat
B. Reject heat
C. Compress vapor
D. Store refrigerant
, Rationale: The condenser rejects heat from the refrigerant to the
outdoor air.
9. A system with a dirty condenser coil will likely have:
A. Low head pressure
B. High head pressure
C. Low suction pressure
D. Normal pressures
Rationale: Restricted airflow across the condenser raises condensing
pressure and temperature.
10.What is the correct unit for measuring vacuum?
A. PSIG
B. Microns
C. PSIA
D. Inches of mercury
Rationale: Microns are used to measure deep vacuum levels during
evacuation.
11.Which of the following is a symptom of a refrigerant undercharge?
A. High subcooling
B. Low subcooling
C. High suction pressure
D. High head pressure
Rationale: Low refrigerant charge results in low subcooling at the
condenser outlet.
12.What is the purpose of a thermostatic expansion valve (TXV)?
A. Control compressor speed
B. Maintain constant superheat
C. Regulate condenser fan speed
D. Measure subcooling
Rationale: A TXV modulates refrigerant flow to maintain a constant
evaporator superheat.
13.Which law states that heat flows from hot to cold?
A. Charles's Law
B. Second Law of Thermodynamics
Technician Certification Practice Exam
100 Questions And Correct Answers
(Verified Answers) Plus Rationales
2026 Q&A Instant Download Pdf
1. Which of the following is the primary function of the evaporator coil in a
refrigeration system?
A. Reject heat to the outdoors
B. Absorb heat from the conditioned space
C. Compress refrigerant vapor
D. Meter refrigerant flow
Rationale: The evaporator coil absorbs heat from the air passing over
it, cooling the space and evaporating the refrigerant.
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 boils at approximately 40°F, which is a
common suction pressure for comfort cooling.
3. Which tool is used to measure the superheat of a system?
A. Manifold gauge only
B. Volt-ohm meter
C. Thermistor thermometer and manifold gauge
D. Vacuum gauge
Rationale: Superheat requires both suction pressure (converted to
saturation temperature) and suction line temperature.
,4. What is the acceptable range for superheat on a fixed orifice system?
A. 0–5°F
B. 5–15°F
C. 15–25°F
D. 25–35°F
Rationale: Fixed orifice systems typically require 5–15°F superheat for
proper operation.
5. Which refrigerant is classified as A1 (non-toxic, non-flammable)?
A. R-22
B. R-410A
C. R-32
D. R-1234yf
Rationale: R-410A is an A1 refrigerant, meaning low toxicity and no
flame propagation.
6. What does a compressor's service valve in the back-seated position do?
A. Allows access to the system
B. Isolates the compressor from the system
C. Bypasses the metering device
D. Opens the liquid line
Rationale: Back-seating the service valve closes the access port and
isolates the compressor from the system.
7. Which component controls the flow of refrigerant into the evaporator?
A. Compressor
B. Condenser
C. Metering device
D. Accumulator
Rationale: The metering device regulates refrigerant flow into the
evaporator.
8. What is the primary purpose of a condenser?
A. Absorb heat
B. Reject heat
C. Compress vapor
D. Store refrigerant
, Rationale: The condenser rejects heat from the refrigerant to the
outdoor air.
9. A system with a dirty condenser coil will likely have:
A. Low head pressure
B. High head pressure
C. Low suction pressure
D. Normal pressures
Rationale: Restricted airflow across the condenser raises condensing
pressure and temperature.
10.What is the correct unit for measuring vacuum?
A. PSIG
B. Microns
C. PSIA
D. Inches of mercury
Rationale: Microns are used to measure deep vacuum levels during
evacuation.
11.Which of the following is a symptom of a refrigerant undercharge?
A. High subcooling
B. Low subcooling
C. High suction pressure
D. High head pressure
Rationale: Low refrigerant charge results in low subcooling at the
condenser outlet.
12.What is the purpose of a thermostatic expansion valve (TXV)?
A. Control compressor speed
B. Maintain constant superheat
C. Regulate condenser fan speed
D. Measure subcooling
Rationale: A TXV modulates refrigerant flow to maintain a constant
evaporator superheat.
13.Which law states that heat flows from hot to cold?
A. Charles's Law
B. Second Law of Thermodynamics
