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NATE_AC_SERVICE NEC 2023

NATE AC Service Practice Test 9

This test covers the refrigerants used in residential AC systems, including R-410A, R-32, R-454B, and older R-22. You will practice knowing the safety classifications and handling differences between them.

TOPICS COVERED

NATE AC Service

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Frequently Asked Questions

Yes — completely free with no signup required. Every question includes a full explanation of the correct answer.

Two: the NATE Core exam plus at least one specialty exam (for example AC Service, Heat Pump Service, or Air Distribution Service). You can take them on the same day or separately.

The Core exam has 50 questions and each installation or service specialty exam has 100 questions. You need 70% on each to pass — 35 of 50 on Core and 70 of 100 on a specialty. Check natex.org for the current format before you book.

NATE certification lasts two years. To renew, you submit 16 hours of continuing education or retake the specialty exam before your certification expires.

No. These are independent practice tests written to match the published NATE exam topics. They are not official NATE exam questions.

Exam Tip: R-410A is a non-flammable A1 refrigerant. Newer R-32 and R-454B are mildly flammable A2L refrigerants that need different handling practices.

30

Questions

30 min

Time

70%

Pass

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NATE AC Service Practice Test 9 — Question List

Question 1: What is R-410A, and how is it classified for safety?

A flammable refrigerant used only in commercial freezers
An older refrigerant no longer found in any equipment
A toxic refrigerant requiring a respirator at all times
The common residential AC refrigerant, classified A1 (non-flammable)

NEC Reference: NULL

Question 2: What is the current status of R-22 refrigerant in the United States?

Production of new R-22 ended in 2020; older systems use recovered/reclaimed supply
R-22 was never used in residential systems
R-22 production continues at full scale with no restrictions
R-22 is a mildly flammable A2L refrigerant

NEC Reference: NULL

Question 3: What does the "A2L" safety classification mean for a refrigerant such as R-32 or R-454B?

Highly toxic and highly flammable, requiring a full hazmat suit
Lower toxicity and mild flammability, requiring different handling than A1
Non-flammable and non-toxic, identical handling to A1
A classification used only for commercial ammonia systems

NEC Reference: NULL

Question 4: What government action is driving the phase-down of R-410A in favor of lower-GWP refrigerants like R-32 and R-454B?

A local building code update
A voluntary manufacturer marketing decision only
The AIM Act
An international refrigerant color-coding standard

NEC Reference: NULL

Question 5: How does R-32's Global Warming Potential (GWP) generally compare to R-410A's?

R-32 has a much higher GWP than R-410A
R-32 and R-410A have identical GWP values
GWP does not apply to R-32 in any way
R-32 has a notably lower GWP than R-410A

NEC Reference: NULL

Question 6: True or False: A technician should never mix different refrigerant types in the same system.

True
False, mixing refrigerants is common and safe practice
False, all refrigerants are chemically identical
False, mixing only matters for A2L refrigerants

NEC Reference: NULL

Question 7: Why can't a technician simply drain R-22 out of an older system and refill it with R-410A as a direct replacement?

R-22 and R-410A are actually fully interchangeable with no changes needed
R-410A operates at different pressures and has different oil needs, requiring compatible equipment
R-410A is illegal to use in any residential application
R-22 systems automatically convert themselves over time

NEC Reference: NULL

Question 8: True or False: Systems using A2L refrigerants like R-32 or R-454B may require specific leak detection sensors and different installation practices compared to A1 refrigerant systems.

False, A2L systems require no special detection equipment
False, A2L and A1 systems always use identical installation practices
True
False, leak detection is never used on refrigerant systems

NEC Reference: NULL

Question 9: How do R-410A operating pressures generally compare to R-22 operating pressures at the same temperature?

R-410A operates at much lower pressures than R-22
R-410A and R-22 always operate at identical pressures
Pressure has no relation to refrigerant type
R-410A operates at notably higher pressures than R-22

NEC Reference: NULL

Question 10: A technician arrives at an older home with an AC system of unknown age. What should be checked first before connecting gauges or adding refrigerant?

The equipment nameplate to confirm the refrigerant type
The homeowner's guess about what refrigerant is used
The color of the outdoor unit cabinet
The thermostat brand only

NEC Reference: NULL

Question 11: True or False: R-454B, like R-32, is being adopted as a lower-GWP alternative to R-410A and also carries an A2L (mildly flammable) safety classification.

False, R-454B is non-flammable (A1)
True
False, R-454B has a higher GWP than R-410A
False, R-454B is not used in residential AC equipment at all

NEC Reference: NULL

Question 12: What does "reclaimed" refrigerant mean?

Refrigerant that has been vented and then recaptured from the atmosphere
A synonym for brand-new refrigerant directly from the manufacturer
Recovered refrigerant processed and certified to meet purity standards for reuse
Refrigerant that has been mixed with nitrogen for storage

NEC Reference: NULL

Question 13: Why does brazing (hot work) on a system that used an A2L refrigerant require extra caution compared to an A1 refrigerant system?

Because A2L refrigerants freeze solid at brazing temperatures
Because brazing is not allowed on any refrigerant system
Because A2L refrigerants become non-flammable when heated
Because residual A2L refrigerant near heat carries more risk than a non-flammable A1 refrigerant

NEC Reference: NULL

Question 14: True or False: Even though refrigerant cylinders often use standard color schemes, a technician should always confirm the refrigerant type by reading the label rather than relying on color alone.

True
False, color alone is always sufficient and labels are unnecessary
False, refrigerant cylinders have no color scheme at all
False, cylinder colors are standardized worldwide with zero exceptions

NEC Reference: NULL

Question 15: Why must a technician use recovery equipment rated for the specific refrigerant type, including for A2L refrigerants?

Equipment ratings are only a marketing detail with no real function
Unrated equipment may not handle the pressure or flammability characteristics safely
All recovery equipment is universally rated for every refrigerant
Recovery equipment rating only matters for commercial systems

NEC Reference: NULL

Question 16: True or False: Different refrigerants are generally paired with specific compatible lubricant oil types, so oil type should not be assumed to be interchangeable across refrigerant types.

False, all refrigerants use exactly the same oil type
False, oil type has no connection to refrigerant type
True
False, oil type only matters for heat pump systems

NEC Reference: NULL

Question 17: Is it accurate to say R-410A is being completely banned overnight, with no more R-410A systems allowed to be serviced?

Yes, all R-410A systems must be replaced immediately by law
Yes, servicing R-410A systems is now illegal in all cases
Yes, R-410A was banned before it was ever used commercially
No, it is a gradual phase-down and existing systems can still be serviced

NEC Reference: NULL

Question 18: A technician suggests simply switching a leaking R-22 system to a different refrigerant instead of repairing the leak. Why is this not a sound solution to a leak problem?

Changing refrigerant type does not fix a physical leak
Switching refrigerant always seals leaks permanently
Leaks only happen with R-22, never with other refrigerants
Leak repair is unnecessary once refrigerant is changed

NEC Reference: NULL

Question 19: True or False: Technicians who handle refrigerant in the United States are generally required to hold appropriate EPA certification for the type of equipment they service.

False, no certification of any kind is required
True
False, certification is only needed for commercial systems, never residential
False, certification requirements were fully eliminated in 2020

NEC Reference: NULL

Question 20: A technician sees pressure readings that look unusually high for what they assumed was an R-410A system. What should be checked before concluding there is a system malfunction?

Immediately replace the compressor without further checks
Assume the gauges are broken and stop troubleshooting
Confirm the actual refrigerant type on the nameplate
Add more refrigerant regardless of the readings

NEC Reference: NULL

Question 21: True or False: R-22 has ozone depletion potential (ODP), which is part of why its production was phased out.

False, R-22 has zero ozone depletion potential
False, ozone depletion only applies to R-410A
False, R-22's phase-out was unrelated to any environmental concern
True

NEC Reference: NULL

Question 22: A homeowner with an old R-22 system asks why recharging it costs more than it used to. What is a reasonable explanation?

Limited recovered/reclaimed supply since new production has ended, raising cost
R-22 has actually become cheaper than R-410A in every case
Recharging cost has nothing to do with refrigerant supply
R-22 is now given away for free by all suppliers

NEC Reference: NULL

Question 23: True or False: A technician should always use the exact refrigerant type approved by the equipment manufacturer, rather than substituting a "similar" refrigerant.

False, any refrigerant with similar pressure can be substituted freely
True
False, refrigerant type does not need to match manufacturer specs
False, substitution is only a concern for A2L refrigerants

NEC Reference: NULL

Question 24: Why might an indoor air handler using an A2L refrigerant need specific installation clearances or ventilation considerations that an R-410A unit in the same space did not need?

Because A2L refrigerants require more electricity to operate
Because A2L equipment is always physically larger
Because A2L refrigerants are mildly flammable, requiring additional safeguards for indoor leaks
Because A2L refrigerants freeze at room temperature

NEC Reference: NULL

Question 25: True or False: A refrigerant identifier tool can be used to confirm the actual refrigerant in a system before recovery, which helps prevent contaminating recovery equipment or cylinders.

False, refrigerant identifiers do not exist as a tool
False, identifying refrigerant before recovery is never useful
False, only the homeowner can confirm refrigerant type
True

NEC Reference: NULL

Question 26: A customer asks why a new system using R-32 or R-454B might involve different installation requirements than their old R-410A system. What is an accurate explanation?

The new refrigerants are mildly flammable, so different safety guidelines apply
There is no real difference and the question is based on a myth
The new refrigerants are radioactive and require lead shielding
The new refrigerants can only be used in commercial buildings

NEC Reference: NULL

Question 27: True or False: Even though both R-32 and R-454B are A2L refrigerants, a technician should still confirm the exact refrigerant type before service, since they are not identical substances.

False, all A2L refrigerants are exactly the same substance
True
False, safety classification alone is enough, exact type does not matter
False, R-32 and R-454B cannot both be A2L at the same time

NEC Reference: NULL

Question 28: Why is specific training important before a technician services equipment using A2L refrigerants for the first time?

Training is not necessary since all refrigerants are handled identically
Training only matters for refrigerant manufacturers, not technicians
A2L refrigerants require different handling and safety practices due to mild flammability
A2L refrigerants are actually easier to handle than any other type

NEC Reference: NULL

Question 29: True or False: A lower GWP (Global Warming Potential) value for a refrigerant generally means less climate impact if that refrigerant is released into the atmosphere.

False, GWP has no connection to environmental impact
False, a higher GWP always means less environmental impact
False, GWP only applies to flammability, not climate impact
True

NEC Reference: NULL

Question 30: Which statement best summarizes the refrigerant landscape a modern AC technician should understand?

R-410A remains common but is phasing down for lower-GWP A2L options, while R-22 systems use reclaimed supply
All refrigerants used today are identical in properties and handling
R-22 is still in full new production today
A2L refrigerants are completely non-flammable, identical to A1

NEC Reference: NULL

EXAM CARD NATE_AC_SERVICE

Questions30

Time limit30 min

Pass score70%

Code editionNEC 2023

DifficultyIntermediate

Last reviewedJun 2026

Timer starts immediately. Progress is auto-saved.

Source: NEC 2026 (NFPA 70)