NATE Air Conditioning Specialty Certification
Exam With Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant Download
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1. What is the primary purpose of the evaporator coil in an air
conditioning system?
A) To compress refrigerant
B) To absorb heat from the indoor air
C) To condense refrigerant
D) To circulate air through ducts
Rationale: The evaporator coil absorbs heat from indoor air,
allowing the refrigerant to evaporate and cool the space.
2. Which refrigerant is commonly used in new residential air
conditioning systems today?
A) R-22
B) R-410A
C) R-12
D) R-134a
Rationale: R-410A has replaced R-22 in new systems due to its
environmental compliance and efficiency.
3. What does SEER stand for in air conditioning systems?
A) Seasonal Energy Efficiency Ratio
B) Standard Energy Efficiency Rating
C) Seasonal Energy Efficiency Ratio
, D) System Energy Evaluation Rating
Rationale: SEER measures the cooling efficiency of an AC system
over an entire cooling season.
4. What is the effect of a dirty air filter on an AC system?
A) Increases cooling capacity
B) Reduces airflow and system efficiency
C) Improves indoor air quality
D) Decreases refrigerant pressure
Rationale: Dirty filters restrict airflow, forcing the system to work
harder and reducing efficiency.
5. Which component is responsible for compressing refrigerant in a
vapor-compression cycle?
A) Evaporator
B) Condenser
C) Compressor
D) Expansion valve
Rationale: The compressor raises refrigerant pressure and
temperature, enabling heat rejection in the condenser.
6. What is the purpose of the expansion device in an AC system?
A) To compress refrigerant
B) To lower the refrigerant pressure before entering the
evaporator
C) To circulate air
D) To remove moisture from air
Rationale: The expansion device reduces pressure and
temperature, allowing refrigerant to evaporate and absorb heat.
, 7. What is the typical temperature drop across an evaporator coil?
A) 10–15°F
B) 15–20°F
C) 18–22°F
D) 25–30°F
Rationale: Properly sized evaporators typically cause an 18–22°F
temperature drop from return to supply air.
8. In a split AC system, where is the condenser located?
A) Indoors
B) Outdoors
C) In the ductwork
D) In the basement
Rationale: The condenser is placed outside to reject heat absorbed
from indoors to the environment.
9. What is superheat in an air conditioning system?
A) Temperature of refrigerant below boiling point
B) Pressure of refrigerant in the condenser
C) Temperature of refrigerant vapor above its saturation
temperature at a given pressure
D) Temperature difference between indoor and outdoor air
Rationale: Superheat ensures that only vapor returns to the
compressor, preventing liquid slugging.
10. Which of the following can cause low refrigerant charge?
A) Dirty air filter
B) Leaks in the refrigerant lines
C) High SEER rating
D) Oversized ductwork
Exam With Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant Download
1. What is the primary purpose of the evaporator coil in an air
conditioning system?
A) To compress refrigerant
B) To absorb heat from the indoor air
C) To condense refrigerant
D) To circulate air through ducts
Rationale: The evaporator coil absorbs heat from indoor air,
allowing the refrigerant to evaporate and cool the space.
2. Which refrigerant is commonly used in new residential air
conditioning systems today?
A) R-22
B) R-410A
C) R-12
D) R-134a
Rationale: R-410A has replaced R-22 in new systems due to its
environmental compliance and efficiency.
3. What does SEER stand for in air conditioning systems?
A) Seasonal Energy Efficiency Ratio
B) Standard Energy Efficiency Rating
C) Seasonal Energy Efficiency Ratio
, D) System Energy Evaluation Rating
Rationale: SEER measures the cooling efficiency of an AC system
over an entire cooling season.
4. What is the effect of a dirty air filter on an AC system?
A) Increases cooling capacity
B) Reduces airflow and system efficiency
C) Improves indoor air quality
D) Decreases refrigerant pressure
Rationale: Dirty filters restrict airflow, forcing the system to work
harder and reducing efficiency.
5. Which component is responsible for compressing refrigerant in a
vapor-compression cycle?
A) Evaporator
B) Condenser
C) Compressor
D) Expansion valve
Rationale: The compressor raises refrigerant pressure and
temperature, enabling heat rejection in the condenser.
6. What is the purpose of the expansion device in an AC system?
A) To compress refrigerant
B) To lower the refrigerant pressure before entering the
evaporator
C) To circulate air
D) To remove moisture from air
Rationale: The expansion device reduces pressure and
temperature, allowing refrigerant to evaporate and absorb heat.
, 7. What is the typical temperature drop across an evaporator coil?
A) 10–15°F
B) 15–20°F
C) 18–22°F
D) 25–30°F
Rationale: Properly sized evaporators typically cause an 18–22°F
temperature drop from return to supply air.
8. In a split AC system, where is the condenser located?
A) Indoors
B) Outdoors
C) In the ductwork
D) In the basement
Rationale: The condenser is placed outside to reject heat absorbed
from indoors to the environment.
9. What is superheat in an air conditioning system?
A) Temperature of refrigerant below boiling point
B) Pressure of refrigerant in the condenser
C) Temperature of refrigerant vapor above its saturation
temperature at a given pressure
D) Temperature difference between indoor and outdoor air
Rationale: Superheat ensures that only vapor returns to the
compressor, preventing liquid slugging.
10. Which of the following can cause low refrigerant charge?
A) Dirty air filter
B) Leaks in the refrigerant lines
C) High SEER rating
D) Oversized ductwork
