NATE Air Conditioning Specialty
Certification Exam With Actual
Questions & Verified Answers, Plus
Explained Rationales/Expert Verified
For Guaranteed Pass 2026/Latest
Updated/Instant Download Pdf
1. What is the primary purpose of a condenser in an air conditioning
system?
A. To compress refrigerant
B. To absorb heat from the indoor air
C. To reject heat to the outside air
D. To expand refrigerant
C. To reject heat to the outside air
Rationale: The condenser removes heat from the refrigerant and
transfers it to the outdoor environment, allowing the refrigerant
to condense into a liquid.
2. What type of compressor is commonly used in residential air
conditioning systems?
A. Centrifugal
B. Scroll
C. Screw
D. Reciprocating
B. Scroll
, Rationale: Scroll compressors are widely used in residential
systems due to their efficiency, reliability, and quiet operation.
3. Which component reduces the high-pressure liquid refrigerant to
a low-pressure liquid before entering the evaporator?
A. Condenser
B. Expansion valve
C. Receiver-drier
D. Compressor
B. Expansion valve
Rationale: The expansion valve regulates refrigerant flow into
the evaporator and reduces pressure to allow evaporation and
heat absorption.
4. What is the main function of the evaporator coil?
A. To remove heat from the indoor air
B. To compress refrigerant
C. To discharge air to the outdoors
D. To filter indoor air
A. To remove heat from the indoor air
Rationale: The evaporator coil absorbs heat from indoor air as
the refrigerant evaporates, providing cooling.
5. Which refrigerant is commonly used in modern air conditioning
systems?
A. R-12
B. R-22
C. R-410A
D. Ammonia
C. R-410A
Rationale: R-410A is widely used due to its higher efficiency and
non-ozone-depleting properties compared to older refrigerants.
,6. What effect does low refrigerant charge have on system
performance?
A. Increased cooling capacity
B. Reduced cooling capacity
C. Increased compressor life
D. No effect
B. Reduced cooling capacity
Rationale: Low refrigerant reduces heat absorption in the
evaporator, lowering cooling efficiency and potentially causing
compressor damage.
7. What is the standard operating pressure for R-410A in a
residential system at 95°F outdoor temperature?
A. 50–100 psi
B. 100–150 psi
C. 300–400 psi
D. 600–700 psi
C. 300–400 psi
Rationale: R-410A operates at higher pressures than R-22,
typically 300–400 psi on the high side at standard temperatures.
8. Which tool is used to measure airflow across the evaporator coil?
A. Manometer
B. Anemometer
C. Thermometer
D. Hygrometer
B. Anemometer
Rationale: An anemometer measures air velocity, which is used
to calculate airflow over coils for system performance
verification.
, 9. What can cause frosting on the evaporator coil?
A. High airflow
B. Dirty air filter
C. Overcharged refrigerant
D. High ambient temperature
B. Dirty air filter
Rationale: A restricted airflow due to a dirty filter reduces heat
transfer, lowering coil temperature and causing frost formation.
10. What is superheat in a vapor-compression system?
A. Temperature of refrigerant leaving the condenser
B. Temperature above boiling point of refrigerant in the
evaporator
C. Temperature at the compressor inlet
D. Difference between high and low side pressures
B. Temperature above boiling point of refrigerant in the
evaporator
Rationale: Superheat ensures that the refrigerant leaving the
evaporator is fully vaporized, protecting the compressor from
liquid slugging.
11. What is subcooling?
A. Heat added to refrigerant in the evaporator
B. Cooling below the refrigerant’s condensing temperature
C. Temperature difference across the expansion valve
D. Cooling of the air leaving the condenser fan
B. Cooling below the refrigerant’s condensing temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled
below its saturation temperature to ensure complete
condensation and efficient operation.
Certification Exam With Actual
Questions & Verified Answers, Plus
Explained Rationales/Expert Verified
For Guaranteed Pass 2026/Latest
Updated/Instant Download Pdf
1. What is the primary purpose of a condenser in an air conditioning
system?
A. To compress refrigerant
B. To absorb heat from the indoor air
C. To reject heat to the outside air
D. To expand refrigerant
C. To reject heat to the outside air
Rationale: The condenser removes heat from the refrigerant and
transfers it to the outdoor environment, allowing the refrigerant
to condense into a liquid.
2. What type of compressor is commonly used in residential air
conditioning systems?
A. Centrifugal
B. Scroll
C. Screw
D. Reciprocating
B. Scroll
, Rationale: Scroll compressors are widely used in residential
systems due to their efficiency, reliability, and quiet operation.
3. Which component reduces the high-pressure liquid refrigerant to
a low-pressure liquid before entering the evaporator?
A. Condenser
B. Expansion valve
C. Receiver-drier
D. Compressor
B. Expansion valve
Rationale: The expansion valve regulates refrigerant flow into
the evaporator and reduces pressure to allow evaporation and
heat absorption.
4. What is the main function of the evaporator coil?
A. To remove heat from the indoor air
B. To compress refrigerant
C. To discharge air to the outdoors
D. To filter indoor air
A. To remove heat from the indoor air
Rationale: The evaporator coil absorbs heat from indoor air as
the refrigerant evaporates, providing cooling.
5. Which refrigerant is commonly used in modern air conditioning
systems?
A. R-12
B. R-22
C. R-410A
D. Ammonia
C. R-410A
Rationale: R-410A is widely used due to its higher efficiency and
non-ozone-depleting properties compared to older refrigerants.
,6. What effect does low refrigerant charge have on system
performance?
A. Increased cooling capacity
B. Reduced cooling capacity
C. Increased compressor life
D. No effect
B. Reduced cooling capacity
Rationale: Low refrigerant reduces heat absorption in the
evaporator, lowering cooling efficiency and potentially causing
compressor damage.
7. What is the standard operating pressure for R-410A in a
residential system at 95°F outdoor temperature?
A. 50–100 psi
B. 100–150 psi
C. 300–400 psi
D. 600–700 psi
C. 300–400 psi
Rationale: R-410A operates at higher pressures than R-22,
typically 300–400 psi on the high side at standard temperatures.
8. Which tool is used to measure airflow across the evaporator coil?
A. Manometer
B. Anemometer
C. Thermometer
D. Hygrometer
B. Anemometer
Rationale: An anemometer measures air velocity, which is used
to calculate airflow over coils for system performance
verification.
, 9. What can cause frosting on the evaporator coil?
A. High airflow
B. Dirty air filter
C. Overcharged refrigerant
D. High ambient temperature
B. Dirty air filter
Rationale: A restricted airflow due to a dirty filter reduces heat
transfer, lowering coil temperature and causing frost formation.
10. What is superheat in a vapor-compression system?
A. Temperature of refrigerant leaving the condenser
B. Temperature above boiling point of refrigerant in the
evaporator
C. Temperature at the compressor inlet
D. Difference between high and low side pressures
B. Temperature above boiling point of refrigerant in the
evaporator
Rationale: Superheat ensures that the refrigerant leaving the
evaporator is fully vaporized, protecting the compressor from
liquid slugging.
11. What is subcooling?
A. Heat added to refrigerant in the evaporator
B. Cooling below the refrigerant’s condensing temperature
C. Temperature difference across the expansion valve
D. Cooling of the air leaving the condenser fan
B. Cooling below the refrigerant’s condensing temperature
Rationale: Subcooling occurs when liquid refrigerant is cooled
below its saturation temperature to ensure complete
condensation and efficient operation.
