PracticeVideosBlogFlashcardsEspañol
All Practice Exams

100+ Free NATE AC Installation Practice Questions

Pass your NATE Air Conditioning Installation Specialty exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
100+ Questions
100% Free

Loading practice questions...

Same family resources

Explore More NATE HVAC Certifications

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

NATE Air Conditioning Service Specialty

Practice Questions

NATE Air Distribution Installation Specialty

Practice Questions

NATE Air Distribution Service Specialty

Practice Questions

NATE Air-to-Air Heat Pump Installation Specialty

Practice Questions

NATE Air-to-Air Heat Pump Service Specialty

Practice Questions

NATE Commercial Refrigeration Service Specialty

Practice Questions
2026 Statistics

Key Facts: NATE AC Installation Exam

100

Practice Questions

OpenExamPrep

100

Exam Questions

NATE

2.5 hours

Time Limit (closed book)

NATE

~70%

Passing Score

NATE

43%

Installation Content Weight

NATE KATE

30 tons

Max System Size Scope

NATE

The NATE Air Conditioning Installation specialty is a 100-question, closed-book, 2.5-hour exam from North American Technician Excellence (NATE) for top-level AC installation technicians working on systems of 30 tons or less. Content is weighted Installation 43%, System Components 27%, Applied Knowledge (codes and design) 20%, and Service 10%, covering refrigerant line installation and brazing, evacuation to 500 microns, weigh-in charging, condensing-unit and coil installation, field wiring (MCA/MOCP), ACCA Manual J/S/D sizing and duct design, and start-up/commissioning. To earn certification you must also pass the 50-question NATE Core exam, and about one year of installation field experience is suggested. This free prep includes 100 research-based practice questions with explanations and an AI tutor.

Sample NATE AC Installation Practice Questions

Try these sample questions to test your NATE AC Installation exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1When evacuating a residential split-system refrigerant circuit before charging, to what vacuum level should a technician pull the system to ensure moisture and non-condensables are removed?
A.29 inches of mercury (Hg)
B.500 microns or lower
C.5,000 microns
D.0 psig
Explanation: Industry best practice and most manufacturers require pulling the system to 500 microns or lower, then performing a decay (standing vacuum) test to confirm the system holds. A micron gauge, not a compound gauge, is required to read this level because a manifold gauge cannot resolve deep vacuum accurately.
2Which instrument must be used to accurately confirm that a system has reached a deep vacuum during evacuation?
A.Compound (manifold) gauge
B.Micron (electronic vacuum) gauge
C.Clamp-on ammeter
D.Sling psychrometer
Explanation: A micron gauge measures absolute pressure in the deep-vacuum range and is the only field tool that can verify 500 microns and a successful decay test. The manifold gauge set is connected for the evacuation process, but it cannot resolve pressures below roughly 1 inch Hg.
3After evacuating a new installation, a technician closes the valve to the vacuum pump and watches the micron gauge. The reading rises and stabilizes at about 1,200 microns. What does this decay test most likely indicate?
A.A perfect, leak-free dry system
B.Remaining moisture boiling off inside the system
C.The refrigerant charge is correct
D.An overcharged condenser
Explanation: A vacuum that rises and then levels off (stabilizes) typically indicates residual moisture in the system boiling off; if it rose continuously without stabilizing, that would indicate a leak. The system should be evacuated longer until it holds at or below 500 microns.
4Which charging method is preferred for a new installation when the manufacturer publishes the exact factory charge plus a per-foot adjustment for line-set length?
A.Superheat method
B.Subcooling method
C.Weigh-in (charge by weight) method
D.Frost-line method
Explanation: On a new install with a known line-set length, the weigh-in method using a charging scale is the most accurate: weigh in the factory charge and add (or subtract) the manufacturer's adjustment for line-set length beyond the factory-supplied amount. Superheat and subcooling are typically used to verify or fine-tune after weigh-in.
5A condensing unit ships with a factory charge sufficient for 15 feet of line set. The actual installation uses a 40-foot line set, and the manufacturer specifies adding 0.6 oz of R-410A per foot beyond 15 feet. How much additional refrigerant must be weighed in?
A.9 oz
B.15 oz
C.24 oz
D.40 oz
Explanation: The excess length is 40 - 15 = 25 feet. Multiplying 25 ft by 0.6 oz/ft gives 15 oz of additional R-410A to weigh in. Following the manufacturer's per-foot adjustment prevents undercharging on long line sets.
6Why must a technician flow dry nitrogen through copper tubing while brazing refrigerant joints during installation?
A.To increase the brazing temperature
B.To prevent the formation of copper oxide (scale) inside the tubing
C.To pressure-test the joint at the same time
D.To cool the joint faster after brazing
Explanation: Purging with dry nitrogen displaces oxygen so that copper oxide scale does not form on the inside of the tubing. Loose oxide flakes can circulate and plug metering devices, filter-driers, and damage the compressor.
7When routing the refrigerant line set, which line is normally insulated?
A.The liquid line only
B.The suction (vapor) line
C.Both lines must be uninsulated
D.Neither line is insulated
Explanation: The large-diameter suction (vapor) line carries cold, low-pressure refrigerant vapor and is insulated to prevent heat gain and condensation/sweating. The smaller liquid line carries warm high-pressure liquid and is normally left uninsulated.
8What is the correct tool sequence when preparing copper tubing for a refrigerant joint?
A.Cut, then braze, then ream
B.Cut, ream, then clean
C.Ream, cut, then flare
D.Clean, braze, then cut
Explanation: Copper tubing is first cut square with a tubing cutter, then reamed to remove the inside burr (which would restrict flow and create turbulence), then cleaned to remove oxidation before fitting and brazing. Skipping the ream leaves a flow restriction.
9A technician needs to join two pieces of copper tubing without a coupling fitting. Which tubing-preparation technique enlarges one tube end so the other slips inside it?
A.Reaming
B.Swaging
C.Flaring
D.Annealing
Explanation: Swaging expands the end of one soft-copper tube so the matching tube fits inside, allowing a brazed joint without a separate coupling. Flaring forms a 45-degree cone for a mechanical flare-nut connection, a different technique.
10A flare connection on a line set is leaking refrigerant after startup. What is the most likely installation cause?
A.The flare nut was over-tightened, cracking the flare
B.Nitrogen was used during evacuation
C.The suction line was insulated
D.The condensate trap was installed
Explanation: Over-tightening a flare nut can split or crack the soft-copper flare, creating a leak; under-tightening leaves a gap. A properly formed 45-degree flare torqued to the manufacturer's spec seals without cracking.

About the NATE AC Installation Exam

The NATE Air Conditioning Installation specialty exam validates a top-level installation technician's knowledge of installing residential and light-commercial AC systems of 30 tons or less. It is a 100-question, closed-book, 2.5-hour exam weighted toward Installation (43%), with System Components (27%), Applied Knowledge: codes and design (20%), and a small Service/diagnostics portion (10%). NATE certification also requires passing the 50-question Core exam.

Assessment

100 closed-book multiple-choice questions over 2.5 hours, weighted Installation 43%, System Components 27%, Applied Knowledge 20%, and Service 10%; NATE certification also requires passing the 50-question Core exam. This practice bank is 100 selected-response items.

Time Limit

2.5 hours

Passing Score

~70% (NATE pass/fail, established by a Passing Score Study)

Exam Fee

~$100-$180 per exam, set by the authorized testing organization (North American Technician Excellence (NATE))

NATE AC Installation Exam Content Outline

43%

Installation

Refrigerant line routing, copper prep, swaging, brazing with nitrogen purge, flare fittings, mounting condensing units and indoor coils, TXV/orifice install, evacuation to 500 microns, charging, leak checks, duct installation, field wiring, and start-up/checkout

27%

System Components

The refrigeration cycle and its components, split and packaged systems, compressors, condensers, indoor coils, metering devices, service valves, line sets, refrigerants and P-T charts, ECM blowers, thermostats, contactors, and controls

20%

Applied Knowledge: Regulations, Codes & Design

ACCA Manual J/S/D and tonnage sizing, MCA/MOCP wire sizing and electrical code, IMC/IECC and condensate code, ASHRAE 62.2 ventilation, comfort and humidity, sound/location, and ACCA 5 Quality Installation

10%

Service (Diagnostics)

Preliminary system and electrical diagnostics on the completed install, voltage and component checks, sight-glass/moisture-indicator reading, coil-icing causes, and sequence of operation

How to Pass the NATE AC Installation Exam

What You Need to Know

  • Passing score: ~70% (NATE pass/fail, established by a Passing Score Study)
  • Assessment: 100 closed-book multiple-choice questions over 2.5 hours, weighted Installation 43%, System Components 27%, Applied Knowledge 20%, and Service 10%; NATE certification also requires passing the 50-question Core exam. This practice bank is 100 selected-response items.
  • Time limit: 2.5 hours
  • Exam fee: ~$100-$180 per exam, set by the authorized testing organization

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

NATE AC Installation Study Tips from Top Performers

1Weight your study toward Installation (43%): line-set routing, brazing with a nitrogen purge, evacuation to 500 microns, and weigh-in charging dominate the exam
2Memorize the charge rules: weigh-in for new installs, subcooling to verify TXV systems, and superheat for fixed-orifice systems
3Know electrical install math: size conductors to the nameplate MCA and the breaker no larger than the MOCP
4Learn the ACCA workflow: Manual J for the load, Manual S to select equipment, and Manual D to size ducts, and why oversizing hurts dehumidification
5Practice commissioning numbers: roughly 400 CFM per ton, a 16-22 degree F temperature split, and total external static pressure
6Complete all 100 practice questions and review every miss with the AI tutor before sitting the exam

Frequently Asked Questions

How many questions are on the NATE AC Installation exam and how long is it?

The Air Conditioning Installation specialty exam has 100 closed-book multiple-choice questions with a 2.5-hour time limit. Content is weighted Installation 43%, System Components 27%, Applied Knowledge 20%, and Service 10%.

What score do I need to pass the NATE AC Installation exam?

NATE reports results as pass/fail, with a passing threshold of roughly 70% established through a formal Passing Score Study. The exact cut score can vary slightly between test forms based on difficulty.

Do I need to pass the NATE Core exam too?

Yes. To become NATE-certified on the traditional pathway you must pass both the 50-question Core exam and this 100-question specialty exam. The Core covers safety, tools, electrical, and HVAC fundamentals shared across specialties.

How is the Installation exam different from the AC Service exam?

The Installation specialty focuses on installing new systems: line-set routing and brazing, mounting equipment, evacuation, weigh-in charging, duct installation, wiring, and start-up. The Service specialty focuses on diagnosing and repairing existing systems and has 100 questions as well.

What experience is recommended before taking the exam?

NATE suggests about one year of field experience as an AC installation technician, plus technical training for theory. There is no formal prerequisite to sit the exam, but experience greatly improves your odds of passing.

Is this free NATE AC Installation practice as good as paid prep?

Our 100 practice questions follow the official KATE content areas with a teaching explanation for every answer, plus free daily AI tutor interactions. All content is free forever and updated for 2026.