NATE Air Conditioning Specialty
Certification Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of the evaporator coil in an air
conditioning system?
A. To remove heat from the indoor air
B. To compress refrigerant
C. To expel heat to the outdoor environment
D. To circulate air through the ductwork
A. To remove heat from the indoor air
Rationale: The evaporator coil absorbs heat from the indoor air, causing
the refrigerant inside to evaporate. This process cools the air before it is
circulated back into the space.
, 2. Which type of refrigerant is commonly used in modern residential
air conditioning systems due to environmental regulations?
A. R-22
B. R-134a
C. R-410A
D. R-12
C. R-410A
Rationale: R-410A has replaced R-22 in most new systems because it has
no ozone depletion potential and operates at higher pressures suitable
for modern AC systems.
3. When measuring superheat in a system, which reading is
necessary to ensure proper system operation?
A. Evaporator inlet temperature
B. Suction line temperature and pressure
C. Condenser discharge pressure
D. Ambient air temperature
B. Suction line temperature and pressure
Rationale: Superheat is calculated using the suction line temperature
and pressure to ensure the evaporator coil is not flooded with liquid
refrigerant, which could damage the compressor.
, 4. Which component of an air conditioning system converts
refrigerant from a high-pressure liquid to a low-pressure vapor?
A. Condenser coil
B. Expansion device
C. Evaporator coil
D. Compressor
B. Expansion device
Rationale: The expansion device (capillary tube or TXV) reduces
refrigerant pressure, allowing it to evaporate and absorb heat in the
evaporator coil.
5. A system’s high-pressure cutout switch is designed to protect
which component?
A. Evaporator coil
B. Compressor
C. Blower motor
D. Expansion valve
B. Compressor
Rationale: High-pressure cutout switches prevent excessive pressure
that could damage the compressor or other system components.
6. What is the effect of low refrigerant charge on system
performance?
, A. Higher cooling efficiency
B. Reduced cooling capacity and possible compressor overheating
C. Increased condenser pressure
D. Increased indoor humidity
B. Reduced cooling capacity and possible compressor overheating
Rationale: Low refrigerant charge reduces heat absorption in the
evaporator, which can cause the compressor to overheat due to
inadequate cooling.
7. Which airflow problem is most likely if the evaporator coil is
freezing?
A. Excessive airflow
B. Restricted airflow
C. Normal airflow
D. Reversed airflow
B. Restricted airflow
Rationale: Restricted airflow prevents the coil from absorbing enough
heat, causing the refrigerant to remain too cold and freeze the coil.
8. Which of the following refrigerant conditions indicates a saturated
vapor in the evaporator coil?
A. Superheated vapor
B. Subcooled liquid
Certification Exam Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of the evaporator coil in an air
conditioning system?
A. To remove heat from the indoor air
B. To compress refrigerant
C. To expel heat to the outdoor environment
D. To circulate air through the ductwork
A. To remove heat from the indoor air
Rationale: The evaporator coil absorbs heat from the indoor air, causing
the refrigerant inside to evaporate. This process cools the air before it is
circulated back into the space.
, 2. Which type of refrigerant is commonly used in modern residential
air conditioning systems due to environmental regulations?
A. R-22
B. R-134a
C. R-410A
D. R-12
C. R-410A
Rationale: R-410A has replaced R-22 in most new systems because it has
no ozone depletion potential and operates at higher pressures suitable
for modern AC systems.
3. When measuring superheat in a system, which reading is
necessary to ensure proper system operation?
A. Evaporator inlet temperature
B. Suction line temperature and pressure
C. Condenser discharge pressure
D. Ambient air temperature
B. Suction line temperature and pressure
Rationale: Superheat is calculated using the suction line temperature
and pressure to ensure the evaporator coil is not flooded with liquid
refrigerant, which could damage the compressor.
, 4. Which component of an air conditioning system converts
refrigerant from a high-pressure liquid to a low-pressure vapor?
A. Condenser coil
B. Expansion device
C. Evaporator coil
D. Compressor
B. Expansion device
Rationale: The expansion device (capillary tube or TXV) reduces
refrigerant pressure, allowing it to evaporate and absorb heat in the
evaporator coil.
5. A system’s high-pressure cutout switch is designed to protect
which component?
A. Evaporator coil
B. Compressor
C. Blower motor
D. Expansion valve
B. Compressor
Rationale: High-pressure cutout switches prevent excessive pressure
that could damage the compressor or other system components.
6. What is the effect of low refrigerant charge on system
performance?
, A. Higher cooling efficiency
B. Reduced cooling capacity and possible compressor overheating
C. Increased condenser pressure
D. Increased indoor humidity
B. Reduced cooling capacity and possible compressor overheating
Rationale: Low refrigerant charge reduces heat absorption in the
evaporator, which can cause the compressor to overheat due to
inadequate cooling.
7. Which airflow problem is most likely if the evaporator coil is
freezing?
A. Excessive airflow
B. Restricted airflow
C. Normal airflow
D. Reversed airflow
B. Restricted airflow
Rationale: Restricted airflow prevents the coil from absorbing enough
heat, causing the refrigerant to remain too cold and freeze the coil.
8. Which of the following refrigerant conditions indicates a saturated
vapor in the evaporator coil?
A. Superheated vapor
B. Subcooled liquid
