- What Is the AZ-ACR Certification?
- Who Hires Contractors With This Credential
- Exam Format and Registration Mechanics
- Domain-by-Domain Question Breakdown
- Approved References and Open-Book Rules
- The Companion Statutes and Rules Exam
- Eligibility and Qualifying Party Rules
- Building an AZ-ACR Study Timeline
- Retakes, Timing, and License Renewal
- Frequently Asked Questions
- The R-39R/C-39 trade exam has 80 scored questions, a 70% passing requirement, and a 210-minute time limit.
- Refrigeration, Air Conditioning, and Warm Air Heating are joint-largest domains with 12 questions each.
- Trade exam costs $66 per attempt; the separate Statutes and Rules Exam (SRE) costs $61.
- Approved open-book references are limited to OSHA 29 CFR 1926, the 2018 IFGC, and the 2018 IMC.
What Is the AZ-ACR Certification?
AZ-ACR, in the context of this site, refers specifically to the Arizona R-39R/C-39 (CR-39) Air Conditioning and Refrigeration (Residential/Commercial) Examination. This is the trade knowledge exam administered on behalf of the Arizona Registrar of Contractors (ROC) through testing provider PSI Services LLC. It is not a national industry certification issued by a manufacturer association or a different licensing body - it is a state contractor licensing exam tied directly to the R-39R residential/commercial and C-39 commercial classification.
Passing this exam is one part of qualifying a contractor's license for HVAC/R work in Arizona. The exam itself does not grant a license; it demonstrates trade competency that, combined with the qualifying party's experience and a separate statutes exam, supports a license application filed with the ROC. If you're still unclear on the terminology, our companion piece on what AZ-ACR actually stands for and the breakdown at AZ-ACR Meaning walk through the naming in more detail.
Who Hires Contractors With This Credential
Because this exam supports a residential/commercial air conditioning and refrigeration contractor license, the people who benefit from passing it are typically HVAC/R technicians moving into ownership or qualifying-party roles: shop owners, service managers becoming licensed qualifying parties, and experienced techs launching their own contracting businesses in Arizona. The classification covers both residential and light commercial systems, so job scopes span single-family cooling and heating equipment, small commercial refrigeration, and rooftop packaged units.
Employers and clients across Arizona's residential and commercial HVAC/R sector look for this license because it signals verified knowledge across refrigeration circuits, air conditioning systems, warm air heating, ductwork, piping, and code-compliant installation practices. If you're weighing whether pursuing this license path makes financial sense for your career, see our ROI analysis and the related earnings overview for qualitative context.
Exam Format and Registration Mechanics
The R-39R/C-39 trade examination is delivered as a computer-based, multiple-choice test. Candidates can sit for it at a physical PSI test center or through remote proctoring, depending on scheduling preference and eligibility for remote delivery.
- Question count: 80 scored questions per the official trade outline.
- Passing score: 70% correct required to pass.
- Time limit: 210 minutes total.
- Experimental items: PSI may insert 5-10 additional unscored experimental questions within the same time block, meaning the total number of items on screen can exceed 80 without extra time being granted.
- Exam fee: $66 per attempt for the trade exam.
The current trade outline was revised June 8, 2023, and PSI's general candidate bulletin governing testing procedures is dated February 18, 2026. Candidates should always reference the most current versions of both documents before test day, since procedural details (identification requirements, remote-testing rules, calculator policy) live in the bulletin rather than the outline. For a deeper walkthrough of exactly how the passing threshold is calculated, read AZ-ACR Passing Score 2026.
Key Takeaway
With 210 minutes for 80 scored questions (plus possible experimental items), candidates average roughly 2.5 minutes per question - tight enough that unfamiliarity with code-book navigation can cost real time.
Domain-by-Domain Question Breakdown
The trade outline organizes content into twelve domains. Question allocations are fixed by PSI's outline, so understanding the weighting tells you exactly where to invest study hours. The full domain list and allocation is below.
| Domain | Topic | Questions |
|---|---|---|
| 1 | Refrigeration | 12 |
| 2 | Air Conditioning | 12 |
| 3 | Warm Air Heating | 12 |
| 4 | Controls and Motors | 8 |
| 5 | Boilers | 4 |
| 6 | Ventilation | 4 |
| 7 | Evaporative Coolers | 4 |
| 8 | Fuel Piping Systems | 5 |
| 9 | Water Piping Systems | 5 |
| 10 | Steam, Hot, Chilled, and Condensing Water | 5 |
| 11 | Testing, Balancing, and Inspections | 5 |
| 12 | Sizing and Estimating | 4 |
Notice that Refrigeration, Air Conditioning, and Warm Air Heating are tied as the joint-largest subject areas at 12 questions apiece - together they account for 36 of the 80 scored questions, or nearly half the exam. Any AZ-ACR study plan that doesn't give these three domains dedicated, roughly equal attention is misallocating effort. For a full explanation of what's tested inside each of the twelve areas, see AZ-ACR Exam Domains 2026: Complete Guide to All 12 Content Areas.
Domain 1: Refrigeration
Covers refrigerant cycle components, system charging, metering devices, and refrigeration-specific troubleshooting scenarios common on commercial and residential equipment.
- Refrigerant flow and pressure-temperature relationships
- Compressor types and refrigeration circuit diagnostics
Domain 2: Air Conditioning
Focused on cooling system design, split and packaged systems, and airflow interactions between indoor and outdoor units.
- Load-related airflow and duct interactions
- Cooling system component sizing and selection
Domain 3: Warm Air Heating
Covers furnace types, combustion airflow, and heating distribution - equally weighted with the two cooling-focused domains above.
- Gas and electric furnace operation
- Heat exchanger and combustion safety concepts
Domains 4, 8, and 9: Controls, Fuel, and Water Piping
Controls and Motors carries 8 questions - the second-heaviest domain - while Fuel Piping Systems and Water Piping Systems each carry 5. These are common places where candidates under-prepare relative to their weight.
- Motor types, starting methods, and control sequencing
- Piping sizing and material selection under the 2018 IFGC
Approved References and Open-Book Rules
Unlike a purely closed-book knowledge test, the R-39R/C-39 exam allows candidates to bring specific reference materials into the testing session. This makes reference navigation speed a real skill, not a footnote.
- OSHA 29 CFR Part 1926 (or PSI's designated selections), with the latest available amendments
- 2018 International Fuel Gas Code (IFGC)
- 2018 International Mechanical Code (IMC)
Any other textbooks named in the outline are labeled study-only references - they help you learn the material beforehand but cannot be brought into the exam room. Before test day, you're allowed to prepare your approved books with advance highlighting, underlining, annotations, and permanent tabs. What's prohibited is bringing loose additional papers or writing new notes in the references during the actual test session.
Remote-proctored sessions carry additional restrictions: scratch paper and breaks are not permitted when testing remotely. Candidates who prefer scratch work for calculations, or who anticipate needing a break during a 210-minute session, may want to schedule at a physical test center instead.
The Companion Statutes and Rules Exam
The trade exam covered throughout this article is separate from the online Arizona Statutes and Rules Exam (SRE), which costs $61 and tests a different body of knowledge - Arizona-specific contractor statutes and licensing rules rather than HVAC/R trade content. Both exams are typically required components of the licensing pathway, but they are scheduled, paid for, and studied separately. Treat SRE preparation as its own track rather than folding it into your trade-exam study time.
Eligibility and Qualifying Party Rules
Before sitting for the trade exam matters much, candidates should confirm they meet the underlying qualifying-party experience standard set by the ROC. Generally, a qualifying party needs four years of practical or management experience in the trade, including at least two years within the preceding ten years. Qualifying technical training can substitute for up to two of the four years. Once earned, exam results must fall within the two years preceding the license application - so timing your exam relative to your intended filing date matters.
These experience thresholds derive from Arizona Revised Statutes sections governing contractor licensing, including ARS 32-1122 and 32-1123.01. For the complete eligibility picture - including documentation candidates typically need to demonstrate qualifying experience - see AZ-ACR Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Key Takeaway
If your qualifying experience is borderline, resolve that question before spending money on trade exam attempts - passing the exam doesn't help if the license application later gets rejected on experience grounds.
Building an AZ-ACR Study Timeline
Generic study techniques like spaced repetition and timed practice blocks only help when they're mapped onto this exam's actual weighting. Since Refrigeration, Air Conditioning, and Warm Air Heating together make up 36 of 80 questions, a realistic multi-week plan should front-load those three domains before moving to lighter-weighted areas.
Refrigeration and Air Conditioning
- Refrigerant cycle mechanics and pressure-temperature charts
- Split-system and packaged-unit airflow scenarios
Warm Air Heating and Controls/Motors
- Furnace combustion and heat exchanger safety
- Motor starting methods and control sequencing (8-question domain)
Piping, Water Systems, and Code Navigation
- Fuel and water piping sizing using the 2018 IFGC/IMC
- Timed tab-and-lookup drills in approved references
Remaining Domains and Full Timed Runs
- Boilers, Ventilation, Evaporative Coolers, Sizing/Estimating, Testing & Balancing
- Full 210-minute practice sessions under realistic conditions
For a structured week-by-week plan with more detail on pacing and review cycles, see AZ-ACR Study Guide 2026: How to Pass on Your First Attempt. And if you're trying to gauge realistically how much preparation this exam demands relative to your background, How Hard Is the AZ-ACR Exam? breaks down the difficulty factors without relying on invented statistics.
Retakes, Timing, and License Renewal
If you don't pass on your first attempt, Arizona's testing rules require a 30-day waiting period before retaking the trade exam. That wait extends to 90 days starting with a fourth attempt, so repeated failed attempts compound scheduling delays significantly - another reason to walk in prepared rather than treating the first sitting as a "practice run."
Once licensed, keep in mind that contractor licenses in Arizona renew on a biennial basis, and license fees plus bond obligations are handled separately from the examination fees discussed here. Exam costs get you through the testing gate; renewal and bonding are ongoing business obligations after licensure. For a full cost picture spanning exam fees through renewal considerations, see AZ-ACR Certification Cost 2026: Complete Pricing Breakdown, and check AZ-ACR Exam Dates 2026 for scheduling windows before you commit to a retake timeline.
To sharpen your readiness before committing to a scheduled date, working through full-length practice tests that mirror the outline's domain weighting is one of the more direct ways to see where your knowledge gaps sit relative to the 70% passing bar. Reviewing a condensed reference like the AZ-ACR Cheat Sheet 2026 alongside timed practice exams can help confirm you're ready before paying the $66 attempt fee again.
Frequently Asked Questions
The R-39R/C-39 trade exam contains 80 scored questions, and candidates need 70% correct to pass within the 210-minute time limit.
Refrigeration, Air Conditioning, and Warm Air Heating are the joint-largest domains, each contributing 12 questions to the 80-question exam.
Approved open-book references are OSHA 29 CFR Part 1926 (or PSI's selections) with current amendments, the 2018 International Fuel Gas Code, and the 2018 International Mechanical Code. Other listed textbooks are for study only and are not permitted in the exam.
No. The trade exam ($66) tests HVAC/R technical knowledge across twelve domains. The online Statutes and Rules Exam (SRE, $61) is a separate exam covering Arizona contractor law and licensing rules.
Retakes generally require a 30-day waiting period. If you reach a fourth attempt, the waiting period extends to 90 days before you can test again.