ACG Certified Commissioning Authority (CxA) Overview
These study notes are designed to prepare candidates for the ACG Certified Commissioning Authority (CxA) exam. They cover the six key subject areas as outlined by Technical Conquer, anchored in official sources such as ASHRAE standards, ICC codes, and ACG/BCxA/NEBB certification guidelines. The notes focus on practical knowledge, field workflows, and diagnostic reasoning for commissioning professionals.
For Technical Conquer practice planning, this module is tracked as 100 questions over about 120 minutes with a listed pass mark of 70%. Treat those numbers as practice baselines and verify the current official format before scheduling.
How This Guide Is Organized
The sections below turn the syllabus into studyable subject blocks. Read a subject first, explain the must-know ideas without notes, then use questions, flashcards, and mind maps to test whether the knowledge holds under field-style pressure.
- Pre-Design and Design Phase Commissioning Activities
- Construction Phase Commissioning Coordination
- Functional Performance Testing and System Integration
- Post-Construction and Occupancy Phase Services
- Existing Building Commissioning (EBCx) Processes
- Commissioning Management and Professional Leadership
Exam Snapshot and Readiness Target
Format: 100 questions, 120 minutes, pass mark 70% (practice baseline; verify with ACG)
Candidate level: Professional with experience in commissioning, HVAC, or building systems
Readiness target: Demonstrate ability to lead commissioning processes across all project phases
Most candidates should budget at least 47+ focused study hours, then adjust upward for unfamiliar equipment, code, regulatory, commissioning, controls, or calculation-heavy content.
Pre-Design and Design Phase Commissioning Activities
Syllabus Focus
- Owner's Project Requirements (OPR)
- Basis of Design (BOD)
- Commissioning plan development
- Design review for commissioning
Key Notes
- OPR defines the owner's functional and performance expectations; it is the foundation for all commissioning activities.
- BOD documents how the design team intends to meet the OPR; CxA reviews BOD for clarity and completeness.
- Commissioning plan is developed during pre-design and updated throughout the project; it includes scope, schedule, roles, and communication protocols.
- Design review focuses on verifying that design documents incorporate OPR requirements, including maintainability, accessibility, and testability.
- ASHRAE Guideline 0 provides a framework for commissioning process; ACG references this guideline.
- Key deliverables: OPR, BOD, preliminary commissioning plan, design review comments.
Must Know
- OPR must be developed with owner input and approved before design proceeds.
- BOD should include system narratives, performance criteria, and assumptions.
- Commissioning plan must identify commissioning team members, responsibilities, and meeting schedule.
- Design review should check for conflicts between systems, inadequate access for maintenance, and missing control sequences.
- CxA should facilitate a commissioning design review meeting to discuss findings.
Field and Exam Application
- Reviewing OPR for a new office building to ensure HVAC zoning matches occupancy patterns.
- Identifying that BOD lacks details on economizer control sequence; requesting clarification.
- Developing a commissioning plan that includes phased testing for a laboratory with fume hoods.
High-Yield Distinctions
- OPR is owner-focused; BOD is design-focused.
- Commissioning plan is a living document; design review is a formal milestone.
- CxA role in design is advisory, not design responsibility.
- ASHRAE Guideline 0 vs. ACG Commissioning Guideline: both emphasize OPR and BOD.
Common Pitfalls
- Assuming OPR is complete without owner sign-off.
- Skipping design review due to schedule pressure.
- Not documenting design review comments and resolutions.
- Confusing commissioning plan with testing plan; commissioning plan is broader.
Review Tasks
- Draft an OPR outline for a typical commercial building.
- List five items to check during a design review of HVAC drawings.
- Create a commissioning plan table of contents.
Construction Phase Commissioning Coordination
Syllabus Focus
- Submittal review
- Site observation and verification
- Commissioning issue resolution
- Systems manual development
Key Notes
- Submittal review ensures equipment and materials meet OPR and design intent; CxA reviews for testability and maintainability.
- Site observations verify installation aligns with approved submittals and design; CxA documents deficiencies.
- Commissioning issues are tracked in a log with responsibility and resolution dates; CxA facilitates resolution.
- Systems manual is a compilation of OPR, BOD, as-built documents, O&M manuals, and commissioning records.
- ACG requires CxA to coordinate with contractors and vendors for testing preparation.
- ASHRAE Guideline 1.2 covers commissioning of existing systems but also informs construction phase activities.
Must Know
- Submittal review should occur before equipment procurement; CxA provides comments to design team.
- Site observation reports should include photos, descriptions, and severity of deficiencies.
- Issue log must be maintained and updated regularly; closed issues require verification.
- Systems manual must be delivered to owner before occupancy.
Field and Exam Application
- Reviewing submittal for a chiller and noting that the specified sensors are not included; requesting correction.
- Observing that ductwork is not insulated per design; documenting deficiency and tracking to resolution.
- Developing a systems manual for a hospital with complex HVAC controls.
High-Yield Distinctions
- Submittal review is a document review; site observation is a physical inspection.
- Issue log is for tracking; systems manual is for owner reference.
- CxA does not supervise construction; CxA verifies installation quality.
Common Pitfalls
- Not reviewing submittals in a timely manner, causing delays.
- Failing to document site observations formally.
- Allowing issues to remain open without resolution plan.
- Systems manual missing critical O&M data.
Review Tasks
- Create a submittal review checklist for an air handling unit.
- Practice writing a site observation report for a mock deficiency.
- List the required contents of a systems manual per ACG guidelines.
Functional Performance Testing and System Integration
Syllabus Focus
- Test procedure development
- Test execution and documentation
- System integration verification
- Seasonal and deferred testing
Key Notes
- Functional performance tests (FPTs) verify systems operate per OPR and design intent under all modes.
- Test procedures include step-by-step instructions, acceptance criteria, and data sheets.
- System integration testing ensures that multiple systems (e.g., HVAC, lighting, fire) interact correctly.
- Seasonal testing may be deferred if weather conditions do not allow full testing; plan for later verification.
- ASHRAE Guideline 0 provides a generic testing framework; ACG specifies CxA responsibilities.
- Test results are documented and signed by CxA and contractor.
Must Know
- FPTs must cover normal, emergency, and shutdown modes.
- Test procedures should be reviewed and approved before execution.
- CxA witnesses tests and records data; contractor operates equipment.
- Deferred testing must be scheduled and tracked to completion.
Field and Exam Application
- Testing a VAV system: verify airflow at design conditions, reheat operation, and zone temperature control.
- Testing integration of HVAC with fire alarm: verify smoke damper closure and fan shutdown.
- Conducting seasonal cooling test in summer; deferring heating test to winter.
High-Yield Distinctions
- FPTs are different from startup and TAB; they verify performance, not just operation.
- System integration testing is often overlooked but critical for building performance.
- Deferred testing requires a written plan and owner approval.
Common Pitfalls
- Writing test procedures that are too vague or too detailed without acceptance criteria.
- Not testing all modes (e.g., only testing occupied mode).
- Skipping integration testing due to complexity.
- Forgetting to follow up on deferred tests.
Review Tasks
- Write a test procedure for a constant volume air handler with economizer.
- List five integration points between HVAC and building automation system.
- Create a deferred testing tracking log.
Post-Construction and Occupancy Phase Services
Syllabus Focus
- Seasonal and deferred testing completion
- Warranty review and support
- Occupancy phase commissioning
- Final commissioning report
Key Notes
- Seasonal and deferred testing must be completed within the warranty period; CxA coordinates with owner and contractors.
- Warranty review includes verifying that systems perform as intended during the first year of operation.
- Occupancy phase commissioning may include training, systems manual updates, and ongoing monitoring.
- Final commissioning report summarizes all activities, results, and unresolved issues.
- ACG requires CxA to provide a final report to owner.
Must Know
- Deferred testing should be scheduled as soon as weather conditions allow.
- Warranty review often involves a site visit at 10-11 months after occupancy.
- Final report must include OPR compliance summary, issue log, and test results.
- Owner training is part of commissioning; CxA may facilitate or verify.
Field and Exam Application
- Completing heating test in winter for a building occupied in summer.
- Conducting warranty review and identifying a chiller that is not meeting efficiency; submitting warranty claim.
- Updating systems manual with as-built control sequences after occupancy.
High-Yield Distinctions
- Post-construction phase is not the end; occupancy phase ensures long-term performance.
- Warranty review is a separate service from initial commissioning.
- Final report is a deliverable; systems manual is another.
Common Pitfalls
- Not completing deferred testing before warranty expires.
- Final report missing unresolved issues or recommendations.
- Assuming owner training is not part of commissioning scope.
Review Tasks
- Outline a final commissioning report structure.
- List three items to check during a warranty review visit.
- Create a checklist for owner training verification.
Existing Building Commissioning (EBCx) Processes
Syllabus Focus
- EBCx planning and investigation
- Energy and performance analysis
- Implementation of improvements
- Ongoing commissioning
Key Notes
- EBCx applies commissioning principles to existing buildings to improve performance and reduce energy use.
- Investigation phase includes reviewing O&M records, utility data, and conducting interviews.
- Energy analysis identifies opportunities for savings; may include benchmarking (e.g., ENERGY STAR).
- Implementation involves low-cost and capital improvements; CxA may assist with measurement and verification.
- Ongoing commissioning establishes continuous monitoring and periodic review.
- ASHRAE Guideline 1.2 is the primary reference for EBCx.
Must Know
- EBCx process includes planning, investigation, implementation, and ongoing commissioning.
- Investigation should identify deficiencies and improvement opportunities.
- Measurement and verification (M&V) follows IPMVP or similar protocols.
- Ongoing commissioning requires owner commitment and resources.
Field and Exam Application
- Investigating a 10-year-old office building with high energy bills; finding that economizer is stuck closed.
- Implementing a schedule change for HVAC to match occupancy; verifying savings with utility data.
- Setting up a monitoring-based commissioning program for a university campus.
High-Yield Distinctions
- EBCx is different from new building commissioning; it focuses on existing systems.
- Ongoing commissioning is a continuous process, not a one-time project.
- M&V is critical to quantify savings.
Common Pitfalls
- Skipping investigation phase and jumping to implementation.
- Not involving building operators in the process.
- Failing to establish baseline energy use before improvements.
Review Tasks
- List five common EBCx measures for HVAC systems.
- Write a sample investigation plan for an existing building.
- Describe how to measure and verify savings from a retrofit.
Commissioning Management and Professional Leadership
Syllabus Focus
- Project management and communication
- Team coordination and leadership
- Quality assurance and documentation
- Ethics and professional responsibility
Key Notes
- CxA manages the commissioning process, not the construction schedule; effective communication is key.
- Team coordination involves facilitating meetings, resolving conflicts, and ensuring all parties understand their roles.
- Quality assurance includes peer review of test procedures and reports.
- Documentation must be organized, complete, and accessible.
- Ethics: CxA must remain impartial and avoid conflicts of interest.
- ACG code of ethics applies to CxA candidates.
Must Know
- CxA should have strong written and verbal communication skills.
- Meeting minutes and action items should be distributed promptly.
- Quality assurance reviews should be conducted before deliverables are issued.
- CxA must not have a financial interest in equipment or systems being commissioned.
Field and Exam Application
- Leading a commissioning team meeting to resolve a scheduling conflict between contractor and testing.
- Reviewing a test procedure written by a junior CxA for completeness.
- Declining a gift from a vendor to maintain impartiality.
High-Yield Distinctions
- CxA is a facilitator, not a project manager.
- Quality assurance is separate from quality control; CxA ensures process quality.
- Ethics violations can result in certification revocation.
Common Pitfalls
- Taking on too many responsibilities outside commissioning scope.
- Poor documentation leading to disputes.
- Failing to maintain impartiality when issues arise.
Review Tasks
- Create a communication plan for a commissioning project.
- List three ethical scenarios and appropriate responses.
- Develop a quality assurance checklist for commissioning deliverables.
How To Use These Notes With Practice Questions
Do not jump straight from reading to a full mock. Work by subject first: review the key notes, make a short recall sheet from memory, then answer a focused question set. After each miss, decide whether the problem was missing theory, weak code/source recall, poor measurement setup, calculation error, or a field sequence you did not visualize.
Technical Conquer's question bank, flashcards, mind maps, and spaced review tools are most useful after this instruction layer because they reveal which parts of the notes are not yet retrievable.
Final Review Checklist
- Review OPR and BOD development process; understand their role in commissioning.
- Practice writing test procedures for common HVAC systems (AHU, VAV, chiller, boiler).
- Familiarize yourself with ASHRAE Guideline 0 and Guideline 1.2.
- Understand the difference between new building commissioning and EBCx.
- Know the contents of a commissioning plan and final report.
- Review ACG certification requirements and code of ethics.
- Practice interpreting control sequences and system integration points.
- Be prepared to discuss measurement and verification protocols (IPMVP).
Official Sources and Further Reading
Use these sources as the final authority for format, eligibility, rules, regulatory limits, and exam updates. Study notes are a preparation layer, not a replacement for official candidate guidance.