AZ-ACR Exam Domains 2026: Complete Guide to All 12 Content Areas

AZ-ACR Exam Structure at a Glance

Every candidate pursuing an R-39R/C-39 (CR-39) residential/commercial air conditioning and refrigeration contractor license in Arizona takes a trade knowledge exam administered by PSI Services LLC on behalf of the Arizona Registrar of Contractors (ROC). This is the version of "AZ-ACR" this site covers: a non-solar HVAC/R trade examination, not a national certification and not any other credential that shares the acronym. Understanding its 12 content domains is the single most useful thing you can do before you schedule a seat.

The trade outline, last revised June 8, 2023, specifies exactly 80 scored questions delivered as computer-based multiple choice, with a 70% passing requirement and a 210-minute time limit. PSI may also insert 5-10 unscored experimental questions that are indistinguishable from scored items, so the practical experience on test day can feel like slightly more than 80 questions. You can sit for the exam at a physical test center or through remote proctoring, depending on what PSI offers for this program.

All 12 Domains and Their Question Weights

The PSI trade outline allocates the 80 scored questions across 12 named domains. These weights are the backbone of any efficient study plan, because they tell you exactly how much of the exam rides on each subject area:

Add those figures up and you get the full 80-question exam. No domain is optional, but the distribution makes clear where PSI expects the deepest, most consistent competency. For a plain-language explanation of how the 70% threshold interacts with this weighting, read AZ-ACR Passing Score 2026: Exactly What You Need to Pass.

The Big Three: Refrigeration, Air Conditioning, Warm Air Heating

Refrigeration, Air Conditioning, and Warm Air Heating are the joint-largest subject areas on the R-39R/C-39 outline, each worth 12 questions. Together they account for 36 of the 80 scored items - 45% of the entire exam. If you master nothing else, master these three.

Mid-Weight Domains: Controls, Piping, and Water Systems

Below the big three sits a tier of domains that individually carry less weight but collectively make up a large share of the exam. Controls and Motors alone is worth 8 questions, and four more domains - Fuel Piping Systems, Water Piping Systems, Steam/Hot/Chilled/Condensing Water, and Testing/Balancing/Inspections - each carry 5 questions.

Because these mid-weight domains draw heavily on the 2018 International Fuel Gas Code and 2018 International Mechanical Code, comfort navigating those references matters as much as memorizing formulas. Our AZ-ACR Cheat Sheet condenses the highest-yield code lookups from these domains onto a single review page.

Smaller but Critical: Sizing, Testing, and Specialty Systems

Boilers, Ventilation, Evaporative Coolers, and Sizing and Estimating each carry only 4 questions, making them the lightest domains on the outline. "Lightest" does not mean skippable - a candidate sitting exactly at the 70% line can't afford to concede any domain entirely, and evaporative cooling in particular is a distinctly Arizona-relevant topic that out-of-state study materials often underserve.

Question Format and Allowed References

Every question on the R-39R/C-39 exam is multiple choice, delivered by computer at a test center or via remote proctoring. Many items are written as original trade scenarios rather than direct definition recall - a symptom description, a code situation, or a sizing problem you must work through, not just a term to identify. Efficient exam-day performance depends on being fast at eliminating wrong answers under time pressure across all 12 domains within the 210-minute window.

This is an open-book exam, but only for specific approved references: OSHA 29 CFR Part 1926 (or PSI's designated equivalent) with the latest available amendments, the 2018 International Fuel Gas Code, and the 2018 International Mechanical Code. Other textbooks listed on the outline are study-only resources and cannot be brought into the exam room. You're permitted to advance-highlight, underline, annotate, and apply permanent tabs to your approved references before test day, but loose additional papers and any new writing inside the references during the exam are prohibited. A silent, nonprinting, nonprogrammable, nonscientific calculator is allowed under the general PSI candidate bulletin. If you test remotely, be aware that scratch paper and breaks are not permitted in that format.

Mapping a Study Plan to the 12 Domains

Rather than studying generically, allocate weeks to domains in proportion to their question weight. A simple approach: spend the most calendar time on the 12-question domains, moderate time on the 5-8 question domains, and a lighter but non-zero pass on the 4-question domains. Spaced repetition works well here - revisit Refrigeration and Air Conditioning terminology every few days rather than cramming it once, since those two domains alone account for nearly a third of the scored questions.

For a broader, non-domain-specific game plan covering timeline, materials, and mindset, pair this schedule with our full AZ-ACR Study Guide 2026.

Registration, Fees, and Retake Rules

Once you understand the domains, the logistics around scheduling matter just as much. The trade examination fee is $66 per attempt, separate from the $61 SRE fee for the online Arizona Statutes and Rules Exam. If you don't pass on your first try, you must wait 30 days before retesting; if you reach a fourth attempt, that waiting period extends to 90 days. Planning your domain review around these windows - rather than rushing back in - usually produces a stronger score the second time.

Eligibility to sit for the exam ties back to the qualifying party's trade experience: ordinarily four years of practical or management experience, including two within the preceding ten years, with qualifying technical training able to substitute for up to two of those years. Exam results must also fall within the two years preceding the actual license application. For the full eligibility breakdown, see AZ-ACR Requirements 2026: Eligibility, Prerequisites & How to Qualify, and for scheduling logistics and testing windows, check AZ-ACR Exam Dates 2026.

Who This Exam Actually Prepares You For

Passing the R-39R/C-39 trade exam and securing an ROC license opens the door to working as, or qualifying, a licensed residential/commercial air conditioning and refrigeration contractor in Arizona. That covers installation and service companies working across all 12 domains covered here - from evaporative cooler retrofits common in older Arizona homes to commercial refrigeration and boiler work in larger buildings. Contractor licenses renew biennially, and license fees and bond obligations are handled separately from the examination fees discussed above.

If you're still weighing whether this path fits your career goals, our companion pieces on AZ-ACR Salary Guide 2026 and Is the AZ-ACR Certification Worth It? dig into the bigger-picture return on the licensing process, while How Hard Is the AZ-ACR Exam? tackles difficulty expectations directly.

Before you commit to a study schedule, it helps to run a handful of scenario-style questions across all 12 domains to see where you stand. You can start building that baseline with the practice questions at the main AZ-ACR practice test site, then return to this domain guide to target your weak areas.

Frequently Asked Questions