- The Credential at a Glance
- Exam Numbers You Must Memorize
- The Five Domains and Their Weights
- Domain-by-Domain Quick Reference
- Standards Named in the Knowledge Base
- Eligibility: The Four Routes
- Application Flow, Fees, and Retake Rules
- Exam-Day Rules and Reference Materials
- Validity and Renewal in One Glance
- Scheduling Review Time by Weight
- Don't Mix It Up With Look-Alike Credentials
- Quick Answers (FAQ)
- The exam has 75 items: 70 scored plus 5 unscored beta items. You need at least 53 of the 70 scored items.
- HVAC Systems (25%) and Method of Procedure (23%) together account for nearly half of the blueprint.
- Eligibility requires qualifying signatory-contractor employment plus one of four experience, education, or IAQ-T routes.
- Fees are USD 125 initial and USD 125 renewal for non-SMART applicants, waived for SMART members.
The Credential at a Glance
The Indoor Air Quality Supervisor (IAQ-S) is issued by the International Certification Board (ICB), the Sheet Metal Industry International Certification Board. The issuer also refers to the credential as IAQ Supervisor/Ventilation Verification. It is a supervisory credential: the blueprint is built around planning IAQ work, directing technicians, reviewing measurements, and signing off on the final report, not just taking readings yourself.
If you are new to the credential, start with What Is IAQ-S? for the big picture, then come back here for the compressed facts. This sheet is built to be scanned, so each section opens with the numbers or rules you are most likely to be tested on or asked about.
Exam Numbers You Must Memorize
| Item | What the Sources Say |
|---|---|
| Total items | 75 |
| Scored items | 70 |
| Unscored beta items | 5 |
| Passing requirement | At least 53 of 70 scored items |
| Format | Written examination, online or paper delivery |
| Proctoring | ICB-designated proctor and site, arranged through the local JATC/training-center coordinator |
| Time limit | No national numeric limit found in current issuer-linked sources; an older externally hosted exam-details document (v2.6, DS230815) lists 2.5 hours, but its current applicability was not verified |
| Testing window | Within one year of application approval |
Two cautions. First, the five beta items are indistinguishable from scored ones, so treat every question seriously. Second, an older ICB manual (Version 210504) adds a rounded "75%" label to 53/70; the number to remember is the raw count of 53 correct scored items. For a deeper breakdown, see IAQ-S Passing Score 2026.
The retrieved current sources do not explicitly establish a multiple-choice response subtype, so avoid assuming the exact question mechanics. NEMI's trained-and-certified overview confirms the IAQ-S exam is written, and that is the safe description.
The Five Domains and Their Weights
The five domain lines are official weighted examination objectives, and the weights total 100%. They are not preparation-course modules, so do not assume a course chapter order mirrors the exam.
| Domain | Weight |
|---|---|
| Domain 1: HVAC Systems | 25% |
| Domain 2: Instrumentation | 15% |
| Domain 3: Supervising the IAQ Technician | 19% |
| Domain 4: Method of Procedure | 23% |
| Domain 5: IAQ Final Report | 18% |
HVAC Systems is the largest domain and Method of Procedure is second. Instrumentation is the smallest, but it feeds directly into the report and supervision domains, so it is not safe to skim. The full objective-level treatment lives in IAQ-S Exam Domains 2026: Complete Guide to All 5 Content Areas.
Domain-by-Domain Quick Reference
Domain 1: HVAC Systems (25%)
The anchor domain. Expect questions on how air-handling systems deliver ventilation and how their performance affects indoor air.
- Outside-air delivery, air balance, and ventilation troubleshooting
- Filtration efficiency and MERV review, tied to the ASHRAE 52.2 reference
- BAS trend interpretation and sensor performance
- Ventilation requirements by occupancy type, tied to the ASHRAE 62.1 and 62.2 references
Domain 2: Instrumentation (15%)
The tools of measurement and the judgment around them. The supervisor's job is to know whether the data can be trusted.
- Instrument selection for the parameter being measured
- Calibration status and equipment availability before work begins
- Measurement review: spotting readings that look wrong or inconsistent
Domain 3: Supervising the IAQ Technician (19%)
This is what separates the supervisor credential from the technician credential. Questions are scenario-style and about oversight.
- Delegation and work scheduling
- Confirming technicians have the right equipment and instructions
- Reviewing technician measurements and data quality before they reach the report
- Safety expectations for field work, including the electrical-safety reference (NFPA 70E)
Domain 4: Method of Procedure (23%)
The planning and execution domain. Think of it as the written plan for how an IAQ job gets done safely and defensibly.
- Scope definition and communication with building stakeholders
- Infection control and site safety, which connects to the healthcare ventilation reference (ASHRAE 170)
- Sequencing work, including building-flush calculations
- Thermal comfort considerations, tied to the ASHRAE 55 reference
Domain 5: IAQ Final Report (18%)
The deliverable. A supervisor signs this, so quality control is the theme.
- Report completeness, accuracy, and defensible conclusions
- Explaining results to customers in plain language
- Connecting measured data to recommended corrective actions
Key Takeaway
The blueprint reads as a workflow: understand the system (Domain 1), choose and verify tools (Domain 2), direct the people (Domain 3), plan the job (Domain 4), and document the outcome (Domain 5). Study it in that order and the objectives start to connect.
Standards Named in the Knowledge Base
The published knowledge base names specific editions of reference standards. These are the outline's reference editions, not claims that they are the newest versions available. Do not silently substitute newer editions when studying for this exam.
| Standard | Edition Named |
|---|---|
| ASHRAE 62.1 | 2019 |
| ASHRAE 62.2 | 2019 |
| ASHRAE 55 | 2017 |
| ASHRAE 170 | 2017 |
| ASHRAE 52.2 | 2017 |
| NFPA 70E | 2018 |
One document-version quirk worth knowing: the manual's cover and latest version-control entry identify 241024, while an internal document-profile table still shows 240429. No separate 2026 exam-form identifier was verified, so cite the 241024 cover version when you reference the scope.
Eligibility: The Four Routes
General supervisor eligibility starts with employment by a contractor that is signatory to a collective bargaining agreement providing direct NEMIC contributions, and current on that agreement's financial obligations. SMART membership is not itself mandatory for supervisors; qualifying signatory employment is. On top of that, you must meet one of four routes:
- An engineering degree and at least one year of HVAC installation/design experience
- A two-year HVAC associate degree and at least three years of that experience
- ICB IAQ Technician certification
- At least three years of HVAC installation/design experience plus a written employer recommendation, where the employer is ICB-certified or eligible apart from the certified-staff requirements
For the full walkthrough, see IAQ-S Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Application Flow, Fees, and Retake Rules
Order of operations
ICB's detailed workflow places application and exam registration first, followed by approval and release of preparation access, then local exam scheduling. NEMI's overview groups training before application, but its Training Courses page agrees that application approval comes before the enrollment code. When the two descriptions seem to conflict, follow the issuer's detailed workflow. The ROC-P portal is the account and application system, not a third-party exam vendor.
NEMI's training lineup includes the IAQ Supervisor Manual, a study guide, an online course, and independent preparation. For more on the preparation side, see IAQ-S Training.
Fees
| Charge | Amount |
|---|---|
| Initial certification (eligible non-SMART applicants) | USD 125 |
| Initial certification (SMART members) | Waived |
| Renewal (non-SMART) | USD 125 |
| Renewal (SMART members) | Waived |
These are certification charges per the ICB Fee Schedule (effective January 1, 2020, still current-linked). No universal course tuition, travel, or local testing charge was verified, so budget separately for any local training. The full picture is in IAQ-S Certification Cost 2026.
Retake waits
- First retest: 30 days
- Second retest: 60 days
- Subsequent attempts: 90 days
Remember that the exam must be taken within one year of application approval. Scheduling logistics are covered in IAQ-S Exam Dates 2026.
Exam-Day Rules and Reference Materials
Proctor-approved reference materials may be used, including authorized electronic reference viewing under exam-security restrictions. That does not make this an unrestricted open-book exam, and it does not establish remote at-home testing. Calculator permission and adaptive delivery were not verified, so confirm calculator rules with your proctor or training-center coordinator before test day.
Practical implication: reference access helps with looking up standards-based values, but it will not rescue you from running out of time. Know where things are in your approved materials, and rely on understanding for the scenario questions in Domains 3, 4, and 5, where there is nothing to look up. If you want a sense of how demanding the test is, read How Hard Is the IAQ-S Exam?.
Validity and Renewal in One Glance
- Validity: two full years from the last day of the quarter in which certification is obtained.
- Renewal application: must be submitted before expiration.
- CEUs: 8 accepted CEUs earned during the certification period. ICB defines one training hour as one CEU, and 8 total accepted units cover all supervisor certifications you hold.
- Conduct: continued eligibility and Code of Conduct compliance are required.
- Employment condition: signing reports or otherwise using the supervisor credential requires qualifying employment with an ICB-certified contractor.
That last point is easy to overlook: holding the credential and being able to use it are tied to who employs you.
Scheduling Review Time by Weight
If you have limited weeks before your proctored sitting, let the blueprint weights drive your calendar. One compact plan:
HVAC Systems first
- Largest weight at 25%, and it underpins everything else
- Practice outside-air, air-balance, and MERV reasoning
Method of Procedure
- Second-largest at 23%
- Work through scope, communication, infection control, and site safety scenarios
Instrumentation and Supervising the IAQ Technician
- Pair the 15% and 19% domains: tools plus the people using them
- Focus on calibration, equipment availability, and measurement review
IAQ Final Report and mixed review
- Report quality and customer explanation (18%)
- Finish with mixed questions across all five domains
For a fuller plan, see the IAQ-S Study Guide 2026, and when you are ready to test yourself, use the IAQ-S practice tests.
Don't Mix It Up With Look-Alike Credentials
Several credentials in the indoor air space sound similar, and mixing them up leads to wasted study time. Keep these separate:
- ICB IAQ Technician (IAQ-T): a different ICB credential with its own blueprint. Do not substitute technician topics for the five supervisor domains. IAQ-T certification is, however, one of the four eligibility routes to the supervisor credential.
- ACAC CIAQM: an adjacent credential from a different issuer with environmental-investigation topics that are not IAQ-S domains.
- General IAQ courses: some courses are built for other audiences, such as commercial property inspectors, and are not aligned to ICB's IAQ-S blueprint.
Also note that no ICB IAQ-S-specific salary dataset or reliable earnings premium was established, and the reviewed official sources did not publish a pass rate. Treat any specific pass-rate or salary figure you encounter with skepticism. See IAQ-S Pass Rate 2026 and the IAQ-S Salary Guide 2026 for what can and cannot be said responsibly, and Is the IAQ-S Certification Worth It? for the broader value question.
If you are exploring how the credential connects to actual roles, IAQ-S Jobs covers the employer side.
Quick Answers (FAQ)
The exam has 75 total items, of which 70 are scored and 5 are unscored beta items. Passing requires at least 53 of the 70 scored items.
HVAC Systems is the largest at 25%, followed by Method of Procedure at 23%, Supervising the IAQ Technician at 19%, IAQ Final Report at 18%, and Instrumentation at 15%.
Proctor-approved reference materials may be used, including authorized electronic viewing under exam-security restrictions. This is not unrestricted open-book testing, so confirm what is allowed with your proctor in advance.
Certification lasts two full years from the last day of the quarter in which you certify. Renewal requires applying before expiration, 8 accepted CEUs earned during the period, continued eligibility, and Code of Conduct compliance.
You wait 30 days before the first retest, 60 days before the second, and 90 days for each subsequent attempt. Remember that testing must occur within one year of application approval.