NATE AC SERVICE EXAM |ACTUAL QUESTIONS
AND VERIFIED ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
A system is supplied from the factory with charge of 5 pounds 10 ounces for a 15 foot line
set. The line set is 25 feet long. The manufacturer's instruction sheet specifies 0.6 ounces
of refrigeration to be added for each added foot of refrigerant line set length. What is the
total refrigerant charge for the system?
A. 6 ounces
B. 5 pounds
C. 5 pounds 10 ounces
D. 6 pounds
CORRECT ANSWER
D. 6 pounds
15ft - 25ft = 10ft x .6 = 6 ounces
5 pounds + 10 ounces + 6 ounces
5 pounds + 16 ounces = 6 pounds
Question 2
The purpose of using flux when soldering is to:
A. anneal the surface.
B. give better heat flow.
C. reduce oxidation.
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,D. pre-seal the oxidation.
CORRECT ANSWER
C. reduce oxidation.
Question 3
Outdoor condensing units that are installed in areas where flooding is possible must:
A. be mounted above flood level.
B. utilize NEMA 1 enclosures.
C. be mounted under an overhanging eave.
D. use water resistant components.
CORRECT ANSWER
A. be mounted above flood level.
Question 4
The component used to reduce sound transmission and prevent water leaks on a rooftop
air conditioner packaged unit installation is the:
A. curb gasket.
B. silicone caulk.
C. roof flashing.
D. roofing tar.
CORRECT ANSWER
A. curb gasket.
2
,Question 5
Return air leakage in a hot attic will:
A. Increase capacity
B. Decrease capacity
C. Increase airflow
D. Decrease airflow
CORRECT ANSWER
B. Decrease capacity
Question 6
An air conditioner refrigerant circuit should be evacuated to a minimum of:
A. 0 microns.
B. 200 microns.
C. 500 microns.
D. 1200 microns.
CORRECT ANSWER
C. 500 microns.
Question 7
Which of the following substances could create an extremely dangerous condition if used
to check refrigeration system for leaks?
A. R-22
B. Nitrogen
3
, C. Oxygen
D. Carbon Dioxide
CORRECT ANSWER
D. Carbon Dioxide
Question 8
The subcooling method for checking charge is generally used on air conditioners with what
type of metering?
A. Only externally equalized thermostatic expansion valves
B. Any thermostatic expansion valve
C. Piston type
D. Any fixed metering device
CORRECT ANSWER
B. Any thermostatic expansion valve
Question 9
Supply ducts running through unconditioned space should be insulated and have:
A. equal friction.
B. excessive air velocity.
C. a vapor barrier.
D. a transition backing.
CORRECT ANSWER
C. a vapor barrier.
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AND VERIFIED ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
A system is supplied from the factory with charge of 5 pounds 10 ounces for a 15 foot line
set. The line set is 25 feet long. The manufacturer's instruction sheet specifies 0.6 ounces
of refrigeration to be added for each added foot of refrigerant line set length. What is the
total refrigerant charge for the system?
A. 6 ounces
B. 5 pounds
C. 5 pounds 10 ounces
D. 6 pounds
CORRECT ANSWER
D. 6 pounds
15ft - 25ft = 10ft x .6 = 6 ounces
5 pounds + 10 ounces + 6 ounces
5 pounds + 16 ounces = 6 pounds
Question 2
The purpose of using flux when soldering is to:
A. anneal the surface.
B. give better heat flow.
C. reduce oxidation.
1
,D. pre-seal the oxidation.
CORRECT ANSWER
C. reduce oxidation.
Question 3
Outdoor condensing units that are installed in areas where flooding is possible must:
A. be mounted above flood level.
B. utilize NEMA 1 enclosures.
C. be mounted under an overhanging eave.
D. use water resistant components.
CORRECT ANSWER
A. be mounted above flood level.
Question 4
The component used to reduce sound transmission and prevent water leaks on a rooftop
air conditioner packaged unit installation is the:
A. curb gasket.
B. silicone caulk.
C. roof flashing.
D. roofing tar.
CORRECT ANSWER
A. curb gasket.
2
,Question 5
Return air leakage in a hot attic will:
A. Increase capacity
B. Decrease capacity
C. Increase airflow
D. Decrease airflow
CORRECT ANSWER
B. Decrease capacity
Question 6
An air conditioner refrigerant circuit should be evacuated to a minimum of:
A. 0 microns.
B. 200 microns.
C. 500 microns.
D. 1200 microns.
CORRECT ANSWER
C. 500 microns.
Question 7
Which of the following substances could create an extremely dangerous condition if used
to check refrigeration system for leaks?
A. R-22
B. Nitrogen
3
, C. Oxygen
D. Carbon Dioxide
CORRECT ANSWER
D. Carbon Dioxide
Question 8
The subcooling method for checking charge is generally used on air conditioners with what
type of metering?
A. Only externally equalized thermostatic expansion valves
B. Any thermostatic expansion valve
C. Piston type
D. Any fixed metering device
CORRECT ANSWER
B. Any thermostatic expansion valve
Question 9
Supply ducts running through unconditioned space should be insulated and have:
A. equal friction.
B. excessive air velocity.
C. a vapor barrier.
D. a transition backing.
CORRECT ANSWER
C. a vapor barrier.
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