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Safety Cue
Task-specific safety guidance for ordinary work hazards.
Project 05
Inspect Ductwork and Diagnose Airflow Problems
Inspect the accessible duct system serving selected rooms and produce an evidence-based airflow-deficiency report, using the system map from Project 01 and the shutdown procedure from Project 02, without redesigning, resizing, or altering the HVAC system.
Field Cue System
These cues appear at the point of work. They identify safety, code, manufacturer, and measurement issues before they become an electrical, combustion, or air-quality hazard.
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Critical Safety Cue
Serious injury, shock, combustion, or exposure hazard is possible.
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Field Safety Cue
Practical work-area safety: lighting, footing, access, and housekeeping.
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Code Alert
Local requirements vary. Verify permit, inspection, and jurisdictional rules.
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Manufacturer Cue
Follow product-specific instructions for equipment, controls, and labels.
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Measurement Cue
Reference-point, verification, and documentation guidance.
Job Overview
This project qualifies you to inspect the accessible duct system serving selected rooms and produce a written, evidence-based airflow-deficiency report. The finished work product is one completed Duct and Airflow Deficiency Report: a documented inspection of accessible supply and return duct runs identifying disconnections, crushing, leakage, undersized-return symptoms, and other restrictions, together with recommended corrections and a clear separation between work this book authorizes and work requiring professional design or licensed service.
You will trace the supply path from equipment plenum to each selected register and the return path from selected return grilles to the equipment; identify disconnected joints, crushed flex duct, sagging, and damaged boots; inspect return paths for undersized-return symptoms; compare room airflow using approved observation or instrumentation; and prepare a deficiency report using location, symptom, confirmation evidence, recommended correction, and priority.
This project depends on the system map completed in Project 01 and uses the shutdown procedure established in Project 02 before any physical inspection begins. The deficiency report produced here directly controls the work performed in Projects 6 through 11: duct sealing, insulation, register-boot work, return-path construction, flexible-duct installation, and airflow balancing. This project does not authorize resizing ducts, redesigning the system, or performing any correction beyond the noninvasive observations described here.
Skills You Will Demonstrate
- HV-025 — Trace duct runs from equipment plenum to selected registers and from selected return grilles to equipment.
- HV-026 — Identify crushed ducts, including collapsed flex liners, sharp bends, and structurally damaged sections.
- HV-027 — Identify disconnected ducts, including open seams, separated joints, and detached boots.
- HV-028 — Identify undersized-return symptoms, including closed-door pressure effects, restricted transfer paths, and filter-related restriction.
- HV-029 — Locate airflow restrictions using approved comparison or measurement methods without altering the system.
- HV-030 — Document duct deficiencies in a structured, evidence-based report with recommended correction and priority.
Where This Skill Fits
This project sits between the basic-service work of Projects 3 and 4 and the duct-system correction work of Projects 6 through 11. The system map from Project 01 identifies what exists; the readiness procedure from Project 02 shuts equipment down safely; this project determines what is wrong with the accessible duct system and where; and Projects 6 through 11 correct only the deficiencies this report identifies as within their scope.
The evidence-based reporting habit established here — location, symptom, confirmation evidence, recommended correction, and priority — is the same structure used again in the comfort-diagnostic work of Project 19.
Scope and Intended Use
This project covers:
- reviewing the system map, complaint history, room uses, filter condition, equipment status, and available duct drawings
- confirming safe access to attics, crawlspaces, basements, closets, and chases
- shutting down equipment before physical duct inspection
- tracing accessible supply and return paths and recording duct material, approximate size, insulation, supports, fittings, dampers, and transitions
- identifying disconnected joints, open seams, crushed flex duct, torn jackets, severe sags, collapsed liners, sharp bends, blocked registers, and damaged boots
- inspecting return grilles and return paths for closed doors, blocked transfer paths, undersized openings, filter restriction, or unintended leakage from dirty spaces
- inspecting accessible dampers for position and operability without changing them yet
- checking for condensation, wet insulation, rust, staining, or biological growth
- comparing room airflow qualitatively or with the approved instrument and test setup
- preparing a deficiency report with location, symptom, confirmation evidence, recommended correction, and priority
This project does not authorize the learner to:
- add ducts, enlarge returns, or change equipment capacity or design
- correct any deficiency identified during this inspection; correction occurs only in the chapter that the report assigns it to
- change damper positions as part of this project; damper adjustment occurs under Project 11
- enter contaminated cavities, mold-affected areas, or spaces with suspected asbestos-containing material
- diagnose refrigerant charge, combustion performance, heat-exchanger condition, or equipment sizing
- continue physical inspection of any area where suspected asbestos-containing duct wrap, transite, vermiculite, lead dust, animal waste, sewage contamination, heavy mold growth, or fire damage is observed
Any deficiency identified in this chapter that requires design calculations, equipment service, duct replacement, or licensed evaluation must be recorded and escalated; it is not corrected as part of this project.
Reference Conventions
Establish these references before beginning the duct inspection, and do not change the defined scope mid-project.
| Term | Definition |
|---|---|
| Selected rooms | The exact rooms and their supply and return paths that this project's inspection and deficiency report apply to |
| Accessible duct | Any duct section, joint, boot, or fitting that can be inspected without opening a finished surface, entering a restricted space, or disturbing hazardous material |
| Disconnected joint | Any duct connection separated far enough to allow visible air leakage or physical gap at the joint |
| Crushed duct | Any duct section, most often flexible duct, whose cross-section is significantly reduced by collapse, sharp bending, or external pressure |
| Undersized-return symptom | An observable condition — such as door-closure pressure effects, a restricted transfer path, or heavy filter loading — consistent with insufficient return-air capacity, without a design calculation confirming undersizing |
| Confirmation evidence | The specific observation, measurement, or comparison that supports a recorded deficiency, as distinct from an assumption |
| Priority | The recorded urgency of a deficiency based on its effect on safety, comfort, or equipment condition, used to sequence correction in later chapters |
Inspection Scope Record
Before beginning the walk-through, record the defined scope directly on the Duct and Airflow Deficiency Report worksheet:
Selected rooms / zone: ______ Complaint or reason for inspection: ______ System map reference (Project 01): ______
Filter condition at time of inspection: ______ Date started: ____________ Builder name: ____________
Prerequisites
- A completed HVAC System Map and Existing-Condition Record from Project 01 for the system or zone being inspected
- A completed HVAC Readiness Checklist from Project 02, or the ability to complete the Project 02 shutdown procedure before physical inspection begins
- Current filter condition confirmed, since a loaded filter can mimic or mask duct-related airflow symptoms
- Safe, permitted access to the attic, crawlspace, basement, closet, or mechanical room containing the duct runs to be inspected
- A stop-work decision authority — the learner, supervisor, or licensed HVAC professional who will be notified if a condition requiring licensed inspection is found
Common Field Fundamentals
Duct inspection is a diagnostic skill built on the identification work of Project 01. A duct traced incorrectly, or a symptom recorded without confirming evidence, produces a deficiency report that sends later chapters to the wrong location or the wrong correction. This project trains the habit of tracing every path completely, recording exactly what confirms each finding, and separating what the book authorizes you to correct from what requires professional design or service.
Supply traceSupply path traced from equipment plenum to each selected register
Return traceReturn path traced from each selected grille to the equipment
Damage IDDisconnections, crushing, sagging, and boot damage identified and recorded
Return symptomsUndersized-return symptoms identified from closed-door and transfer-path observations
Airflow comparisonRoom airflow compared using the approved observation or instrument method
Moisture and growthCondensation, wet insulation, rust, staining, and biological growth checked and recorded
Scope separationFindings sorted into book-scope corrections and professional-referral items
DocumentationDeficiency report completed with location, symptom, evidence, correction, and priority
Diagnosis Without Redesign
This project diagnoses accessible duct and airflow conditions only. It does not authorize adding ducts, enlarging returns, resizing branches, or changing equipment capacity. A finding that appears to require any of these actions must be recorded as requiring design calculations or licensed evaluation, not corrected or assumed resolved by a larger duct or return opening chosen in the field.
HV-025 – HV-030
Diagnostic / Inspection / Deficiency-Reporting Qualification
Inspect Ductwork and Diagnose Airflow Problems
A. Finished-Project Specification
Quantity: one defined set of selected rooms, traced supply and return paths, identified duct deficiencies with confirming evidence, identified return-path concerns, completed airflow comparison, and completed Duct and Airflow Deficiency Report separating book-scope corrections from professional-referral items.
B. Duct Inspection and Diagnosis Schedule
| Item | Target Condition | Verification Method |
|---|---|---|
| Selected rooms and scope | Defined and does not change mid-project | Written record on worksheet |
| Supply-path trace | Every selected supply path traced from equipment plenum to register | Visual trace and written record |
| Return-path trace | Every selected return path traced from grille to equipment | Visual trace and written record |
| Duct condition | Disconnections, crushing, sagging, and boot damage identified with location and evidence | Visual confirmation and photograph |
| Return-path condition | Undersized-return symptoms identified with confirming evidence | Observation under defined door and operating conditions |
| Room airflow comparison | Compared using the approved observation or instrument method | Recorded comparison under stable operating condition |
| Deficiency report | Every finding recorded with location, symptom, evidence, recommended correction, and priority | Completed written report |
C. Material Takeoff
- Documentation materials: one Duct and Airflow Deficiency Report worksheet, the Project 01 system map for reference.
- Field materials: labels or tags for marking deficiency locations pending later correction.
- Photographic record: photographs of every identified deficiency, damaged section, and confirming-evidence observation.
D. Acceptance Standards
| Check | Standard |
|---|---|
| Duct tracing | Every selected supply and return path traced from equipment to register or grille, or to the point access ends |
| Deficiency identification | Every disconnection, crushed section, sag, and damaged boot recorded with location and confirming evidence |
| Return-path evaluation | Every undersized-return symptom recorded with confirming observation under a defined condition |
| Airflow comparison | Room airflow compared using the approved observation or instrument method under a stable operating condition |
| Scope separation | Every finding classified as within book scope for Projects 6 through 11 or as requiring professional design or service |
| Documentation | Duct and Airflow Deficiency Report complete with location, symptom, evidence, recommended correction, and priority for every finding |
| Procedure | Preparation, safe access confirmation, shutdown, supply tracing, return tracing, deficiency identification, airflow comparison, and reporting completed independently and in sequence |
E. Preparation and Prior-Record Review
- Review the system map, complaint history, room uses, filter condition, equipment status, and available duct drawings. Confirm the system map from Project 01 matches the system or zone to be inspected.
- Confirm safe access to attics, crawlspaces, basements, closets, and chases. Verify structural support, lighting, and confined-space conditions before entering any area.
F. Shutdown and Access Preparation
- Shut down equipment before physical duct inspection. Apply the complete Project 02 shutdown and readiness procedure and confirm the equipment cannot start unexpectedly.
- Inspect access areas for structural, electrical, pest, insulation, heat, confined-space, and contamination hazards. Stop work in any area where a stop-work condition is observed and record it before proceeding elsewhere.
G. Supply and Return Path Tracing
- Trace the supply path from equipment plenum to each selected register. Follow the path continuously and note where access ends if the full path cannot be observed.
- Trace the return path from selected return grilles to the equipment. Follow the path continuously and note where access ends if the full path cannot be observed.
- Record duct material, approximate size, insulation, supports, fittings, dampers, and transitions. Use the tape measure for approximate sizes and record each fitting and transition by location.
H. Duct Damage and Deficiency Identification
- Identify disconnected joints, open seams, crushed flex duct, torn jackets, severe sags, collapsed liners, sharp bends, blocked registers, and damaged boots. Record the exact location, the specific evidence observed, and a photograph for each.
- Inspect return grilles and return paths for closed doors, blocked transfer paths, undersized openings, filter restriction, or unintended leakage from dirty spaces. Record the confirming observation for each undersized-return symptom.
- Inspect accessible dampers for position and operability without changing them yet. Record the as-found position of every damper without adjusting it.
- Check for condensation, wet insulation, rust, staining, or biological growth. Record the location and extent of any moisture-related condition found.
- Stop work for suspected asbestos, severe mold, sewage contamination, fire damage, or unsafe access. Record the condition and its location, and escalate to a qualified professional rather than continuing inspection of that area.
I. Airflow Comparison and Restriction Location
- Restore equipment and perform only noninvasive observations with all safety panels installed. Confirm no panels or covers remain open before restoring power.
- Compare room airflow qualitatively or with the approved instrument and test setup. Use the same method and operating condition for every selected room to keep the comparison valid.
- Record room temperature differences under defined operating conditions where required. Note the thermostat setting, run time, and outdoor condition at the time of the comparison.
- Distinguish equipment-capacity symptoms from obvious distribution restrictions without making unsupported conclusions. Record only what the evidence supports; mark ambiguous findings as requiring further evaluation rather than assuming a cause.
J. Scope Classification and Deficiency Reporting
- Identify deficiencies that can be corrected under Projects 6–11. Match each finding to the specific later-chapter scope that authorizes its correction.
- Identify conditions requiring design calculations, equipment service, duct replacement, or licensed evaluation. Record these separately and do not assign them to a book-scope correction.
- Prepare a deficiency report with location, symptom, confirmation evidence, recommended correction, and priority. Complete one entry for every finding recorded during the inspection.
- Do not recommend adding ducts, enlarging returns, or changing equipment without approved design review. Confirm the report contains no such recommendation before completing it.
Common Readiness Inspection
Inspect every completed deficiency report using the same checks regardless of which residence or training system the project involves.
- Tracing check: confirm every selected supply and return path is traced from equipment to register or grille, or to the limit of access.
- Deficiency check: confirm every disconnection, crushed section, sag, and damaged boot is recorded with location and confirming evidence.
- Return-path check: confirm every undersized-return symptom is recorded with a confirming observation.
- Airflow-comparison check: confirm room airflow was compared using the same method and operating condition for every selected room.
- Scope check: confirm every finding is classified as book-scope or professional-referral, with no unsupported recommendation to add ducts, enlarge returns, or change equipment.
- Documentation check: confirm the Duct and Airflow Deficiency Report is fully completed.
Complete the Duct and Airflow Deficiency Report in the Inspection Checklist section below before beginning Project 06.
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Failure Points and Troubleshooting
Cleanup
This project ends with the deficiency report completed and the work area left undisturbed, not altered further until the assigned correction chapter begins.
- Confirm all photographs are labeled and stored with the deficiency report worksheet
- Confirm every access panel, attic hatch, or crawlspace cover opened for inspection is closed and secured
- Confirm labels or tags applied to deficiency locations remain in place
- Confirm equipment has been restored to normal operation with all panels reinstalled
- Store the tape measure, flashlight, camera, and any airflow-comparison instrument in a protected, undamaged condition
- Store the Duct and Airflow Deficiency Report for reference by Projects 6 through 11
Field Terms
- Selected Rooms
- The exact rooms and their supply and return paths that this project's inspection and deficiency report apply to.
- Accessible Duct
- Any duct section, joint, boot, or fitting that can be inspected without opening a finished surface, entering a restricted space, or disturbing hazardous material.
- Disconnected Joint
- Any duct connection separated far enough to allow visible air leakage or physical gap at the joint.
- Crushed Duct
- Any duct section, most often flexible duct, whose cross-section is significantly reduced by collapse, sharp bending, or external pressure.
- Undersized-Return Symptom
- An observable condition consistent with insufficient return-air capacity, without a design calculation confirming undersizing.
- Confirmation Evidence
- The specific observation, measurement, or comparison that supports a recorded deficiency, as distinct from an assumption.
- Priority
- The recorded urgency of a deficiency based on its effect on safety, comfort, or equipment condition, used to sequence correction in later chapters.
- Deficiency Report
- The structured written record of every duct and airflow finding, including location, symptom, confirmation evidence, recommended correction, and priority.
Skill Check
- Why must the supply and return paths be traced continuously from equipment to register or grille rather than spot-checked at a few points?
- What confirming evidence is required before a duct condition may be recorded as a deficiency?
- How does an undersized-return symptom differ from a confirmed undersized-return design condition, and why does this project record only the symptom?
- Why must equipment be shut down before physical duct inspection begins, and why is airflow comparison performed only after equipment is restored with all panels installed?
- What must the learner do when a duct cannot be traced to its termination because access ends?
- Why does this project not authorize adding ducts, enlarging returns, or changing equipment capacity?
- What conditions observed during the inspection require the learner to stop work in an area and escalate rather than continue?
- Why must every deficiency be classified as either within the scope of Projects 6 through 11 or as requiring professional design or licensed service?
- Why must airflow comparisons use the same method and operating condition across every selected room?
- Why does the completed deficiency report control the work performed in later chapters rather than allowing those chapters to redefine the problem?
Competency Rubric
| Competency | Independent Pass Standard | Not Demonstrated | With Assistance | Independently |
|---|---|---|---|---|
| HV-025 | Traces duct runs from equipment plenum to selected registers and from selected return grilles to equipment | |||
| HV-026 | Identifies crushed ducts, including collapsed flex liners, sharp bends, and structurally damaged sections | |||
| HV-027 | Identifies disconnected ducts, including open seams, separated joints, and detached boots | |||
| HV-028 | Identifies undersized-return symptoms with confirming observation under defined conditions | |||
| HV-029 | Locates airflow restrictions using approved comparison or measurement methods without altering the system | |||
| HV-030 | Documents duct deficiencies in a structured, evidence-based report with recommended correction and priority |
Mark one column per competency. Only Demonstrated Independently awards the competency; Demonstrated with Assistance authorizes additional supervised practice but does not complete the requirement.
Inspection Checklist — Duct and Airflow Deficiency Report
| Item | Target Condition | Result | Pass/Fail | Correction (if any) |
|---|---|---|---|---|
| Scope definition | Selected rooms and zone defined in writing before inspection began | |||
| Supply-path trace | Traced from equipment plenum to each selected register or to the limit of access | |||
| Return-path trace | Traced from each selected return grille to equipment or to the limit of access | |||
| Duct deficiencies | Disconnections, crushing, sagging, and damaged boots recorded with location and evidence | |||
| Return-path symptoms | Undersized-return symptoms recorded with confirming observation | |||
| Airflow comparison | Completed using the same method and operating condition across selected rooms | |||
| Scope classification | Every finding classified as book-scope or professional-referral |
Unresolved conditions and escalation notes: ____________________________________________
Deficiency report declared ready: ______ (Pass/Fail) Date: ____________ Builder name: ____________
Performance Check
With the supply and return paths traced, duct deficiencies identified with confirming evidence, undersized-return symptoms recorded, airflow comparison completed, and every finding classified, review the finished report against the Acceptance Standards table and confirm every selected path is traced to its termination or to the limit of access, every deficiency has recorded location and evidence, every undersized-return symptom is supported by a confirming observation, the airflow comparison used a consistent method and operating condition, and every finding is correctly classified as book-scope or professional-referral with no unsupported recommendation to add ducts, enlarge returns, or change equipment. Complete the Duct and Airflow Deficiency Report and correct any failed item before beginning Project 06. If an item fails, identify whether the error occurred in path tracing, deficiency identification, return-path evaluation, airflow comparison, or scope classification before correcting it and re-running the affected check.
Project Closeout
You have completed the fifth project in the residential HVAC sequence: inspecting ductwork and diagnosing airflow problems. This project required you to trace supply and return duct paths, identify crushed and disconnected ducts, identify undersized-return symptoms, locate airflow restrictions using approved methods, and document every finding in a structured, evidence-based deficiency report (HV-025 through HV-030).
You now have a verified deficiency report you can reference for every duct-correction project that follows. That record carries directly into the next project: sealing the accessible leakage points this inspection identified using mastic and HVAC-rated tape.
Retain your Duct and Airflow Deficiency Report. You will reference this exact report before beginning Project 06 and throughout Projects 6 through 11.