HVAC Excellence Master Specialist
Certification Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which type of refrigerant is classified as a hydrofluorocarbon
(HFC) and does not contribute to ozone depletion?
A. R-22
B. R-410A
C. R-12
D. R-502
Rationale: R-410A is an HFC refrigerant and contains no chlorine, so it
does not deplete the ozone layer. R-22 and R-502 are
hydrochlorofluorocarbons (HCFCs) with ozone-depleting potential, and
R-12 is a chlorofluorocarbon (CFC).
2. In a refrigeration cycle, which component is responsible for
removing heat from the indoor air?
, A. Condenser
B. Compressor
C. Evaporator
D. Expansion valve
Rationale: The evaporator absorbs heat from the indoor environment
and allows the refrigerant to evaporate, removing heat and cooling
the air. The condenser releases heat outside, the compressor increases
refrigerant pressure, and the expansion valve regulates flow.
3. What is the primary purpose of a TXV (thermostatic expansion
valve) in an HVAC system?
A. Increase refrigerant pressure
B. Control refrigerant flow into the evaporator
C. Condense refrigerant
D. Act as a safety device
Rationale: A TXV meters the correct amount of refrigerant into the
evaporator to maintain optimal superheat. It does not compress,
condense, or act as a safety device.
4. Which electrical component in a split system air conditioner starts
the compressor?
A. Capacitor
B. Contactor
, C. Relay
D. Transformer
Rationale: The relay acts as a switch to start the compressor by
completing the high-voltage circuit when energized by the low-voltage
control signal. Capacitors assist in motor start/run, the contactor
controls high-voltage circuits, and transformers step down voltage.
5. A system has a suction pressure of 60 psi and a corresponding
evaporator temperature of 35°F. Which type of refrigerant is most
likely in use?
A. R-22
B. R-134a
C. R-410A
D. R-404A
Rationale: R-410A has higher pressure characteristics than R-22 or R-
134a. At 35°F evaporator temperature, 60 psi is consistent with R-
410A operating pressures.
6. Which tool is essential for leak detection in a system using HFC
refrigerants?
A. Combustion analyzer
B. Electronic refrigerant leak detector
, C. Hydrometer
D. Anemometer
Rationale: Electronic refrigerant leak detectors can sense small leaks
of HFC refrigerants, while combustion analyzers, hydrometers, and
anemometers serve unrelated functions.
7. Superheat in an HVAC system is the temperature:
A. At which refrigerant condenses
B. At which refrigerant evaporates
C. Above the refrigerant’s saturation temperature in the
evaporator
D. Below the ambient air temperature
Rationale: Superheat is the temperature above the refrigerant's
saturation temperature after it has fully evaporated. It ensures that
only vapor returns to the compressor.
8. Which is the primary cause of low airflow over an evaporator coil?
A. Overcharged refrigerant
B. Dirty condenser coil
C. Clogged air filter or duct restrictions
D. High superheat
Certification Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. Which type of refrigerant is classified as a hydrofluorocarbon
(HFC) and does not contribute to ozone depletion?
A. R-22
B. R-410A
C. R-12
D. R-502
Rationale: R-410A is an HFC refrigerant and contains no chlorine, so it
does not deplete the ozone layer. R-22 and R-502 are
hydrochlorofluorocarbons (HCFCs) with ozone-depleting potential, and
R-12 is a chlorofluorocarbon (CFC).
2. In a refrigeration cycle, which component is responsible for
removing heat from the indoor air?
, A. Condenser
B. Compressor
C. Evaporator
D. Expansion valve
Rationale: The evaporator absorbs heat from the indoor environment
and allows the refrigerant to evaporate, removing heat and cooling
the air. The condenser releases heat outside, the compressor increases
refrigerant pressure, and the expansion valve regulates flow.
3. What is the primary purpose of a TXV (thermostatic expansion
valve) in an HVAC system?
A. Increase refrigerant pressure
B. Control refrigerant flow into the evaporator
C. Condense refrigerant
D. Act as a safety device
Rationale: A TXV meters the correct amount of refrigerant into the
evaporator to maintain optimal superheat. It does not compress,
condense, or act as a safety device.
4. Which electrical component in a split system air conditioner starts
the compressor?
A. Capacitor
B. Contactor
, C. Relay
D. Transformer
Rationale: The relay acts as a switch to start the compressor by
completing the high-voltage circuit when energized by the low-voltage
control signal. Capacitors assist in motor start/run, the contactor
controls high-voltage circuits, and transformers step down voltage.
5. A system has a suction pressure of 60 psi and a corresponding
evaporator temperature of 35°F. Which type of refrigerant is most
likely in use?
A. R-22
B. R-134a
C. R-410A
D. R-404A
Rationale: R-410A has higher pressure characteristics than R-22 or R-
134a. At 35°F evaporator temperature, 60 psi is consistent with R-
410A operating pressures.
6. Which tool is essential for leak detection in a system using HFC
refrigerants?
A. Combustion analyzer
B. Electronic refrigerant leak detector
, C. Hydrometer
D. Anemometer
Rationale: Electronic refrigerant leak detectors can sense small leaks
of HFC refrigerants, while combustion analyzers, hydrometers, and
anemometers serve unrelated functions.
7. Superheat in an HVAC system is the temperature:
A. At which refrigerant condenses
B. At which refrigerant evaporates
C. Above the refrigerant’s saturation temperature in the
evaporator
D. Below the ambient air temperature
Rationale: Superheat is the temperature above the refrigerant's
saturation temperature after it has fully evaporated. It ensures that
only vapor returns to the compressor.
8. Which is the primary cause of low airflow over an evaporator coil?
A. Overcharged refrigerant
B. Dirty condenser coil
C. Clogged air filter or duct restrictions
D. High superheat
