NATE Core Service Certification Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. What is the primary purpose of a heat pump in a residential
system?
A. To transfer heat from one location to another
B. To generate heat through combustion
C. To cool air using water
D. To increase indoor air pressure
Heat pumps move heat rather than generate it, allowing both
heating and cooling.
2. Which of the following is a common symptom of a refrigerant
leak?
A. Increased air pressure
B. Frost on the evaporator coil
C. Higher system efficiency
D. Reduced airflow
Refrigerant leaks often cause the evaporator coil to freeze due to
low pressure.
3. What is the standard voltage for most residential air conditioning
systems in the U.S.?
A. 120 V
, B. 240 V
C. 208 V
D. 480 V
Most central air conditioning units use 240 volts for efficiency and
power requirements.
4. When should a technician perform a superheat measurement?
A. During compressor startup
B. Only during cooling season
C. When charging a system or diagnosing performance issues
D. After replacing the thermostat
Superheat helps determine if the refrigerant charge is correct.
5. What type of filter is most effective at capturing small airborne
particles?
A. Fiberglass
B. Washable mesh
C. HEPA
D. Polyester
HEPA filters can capture very fine particles, improving indoor air
quality.
6. Which component stores excess liquid refrigerant in a system?
A. Expansion valve
B. Compressor
C. Receiver/drier
D. Evaporator coil
The receiver/drier prevents liquid from entering the compressor
and removes moisture.
, 7. What is the typical airflow across a residential evaporator coil?
A. 200–300 CFM per ton
B. 400–450 CFM per ton
C. 600–700 CFM per ton
D. 800–900 CFM per ton
Proper airflow ensures efficient heat transfer and system longevity.
8. What is the effect of a dirty air filter on system performance?
A. Increases heating efficiency
B. Reduces airflow and increases energy use
C. Improves refrigerant flow
D. Lowers indoor humidity
Restricted airflow reduces system efficiency and can damage
components.
9. Which refrigerant is considered non-ozone depleting and widely
used in new residential systems?
A. R-22
B. R-12
C. R-410A
D. R-502
R-410A does not deplete the ozone layer and is standard in
modern HVAC systems.
10. What safety device prevents excessive pressure in a
refrigerant system?
A. Thermostat
B. High-pressure switch
C. Expansion valve
D. Contactor
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. What is the primary purpose of a heat pump in a residential
system?
A. To transfer heat from one location to another
B. To generate heat through combustion
C. To cool air using water
D. To increase indoor air pressure
Heat pumps move heat rather than generate it, allowing both
heating and cooling.
2. Which of the following is a common symptom of a refrigerant
leak?
A. Increased air pressure
B. Frost on the evaporator coil
C. Higher system efficiency
D. Reduced airflow
Refrigerant leaks often cause the evaporator coil to freeze due to
low pressure.
3. What is the standard voltage for most residential air conditioning
systems in the U.S.?
A. 120 V
, B. 240 V
C. 208 V
D. 480 V
Most central air conditioning units use 240 volts for efficiency and
power requirements.
4. When should a technician perform a superheat measurement?
A. During compressor startup
B. Only during cooling season
C. When charging a system or diagnosing performance issues
D. After replacing the thermostat
Superheat helps determine if the refrigerant charge is correct.
5. What type of filter is most effective at capturing small airborne
particles?
A. Fiberglass
B. Washable mesh
C. HEPA
D. Polyester
HEPA filters can capture very fine particles, improving indoor air
quality.
6. Which component stores excess liquid refrigerant in a system?
A. Expansion valve
B. Compressor
C. Receiver/drier
D. Evaporator coil
The receiver/drier prevents liquid from entering the compressor
and removes moisture.
, 7. What is the typical airflow across a residential evaporator coil?
A. 200–300 CFM per ton
B. 400–450 CFM per ton
C. 600–700 CFM per ton
D. 800–900 CFM per ton
Proper airflow ensures efficient heat transfer and system longevity.
8. What is the effect of a dirty air filter on system performance?
A. Increases heating efficiency
B. Reduces airflow and increases energy use
C. Improves refrigerant flow
D. Lowers indoor humidity
Restricted airflow reduces system efficiency and can damage
components.
9. Which refrigerant is considered non-ozone depleting and widely
used in new residential systems?
A. R-22
B. R-12
C. R-410A
D. R-502
R-410A does not deplete the ozone layer and is standard in
modern HVAC systems.
10. What safety device prevents excessive pressure in a
refrigerant system?
A. Thermostat
B. High-pressure switch
C. Expansion valve
D. Contactor
