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Safety Cue
Task-specific safety guidance for ordinary work hazards.
Project 01
Identify and Document a Residential HVAC System
Trace and document the visible heating, cooling, air-distribution, ventilation, filtration, condensate, and control components serving a selected residence or training system, without opening energized or restricted equipment, so every later project in this book begins from a verified, written system map rather than an assumed layout.
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 identify and document the visible components of one residential HVAC system without opening energized equipment, refrigerant circuits, or restricted covers. The finished work product is one completed HVAC System Map and Existing-Condition Record: a written and photographed inventory of the heating equipment, cooling equipment, air-distribution paths, ventilation components, condensate system, and controls serving the selected system or zone.
You will define the system or zone included in the project; identify the heating and cooling equipment by type, location, and visible labels; trace visible supply and return duct paths; identify ventilation, exhaust, and condensate components; identify thermostats, disconnects, and breakers without removing restricted covers; mark unresolved components rather than guessing at their function; and prepare a schematic and existing-condition record comparing field conditions with any available drawings.
This is the first project in the book. Every later chapter — filter service, grille cleaning, duct inspection and sealing, insulation, register and return work, flexible duct, balancing, thermostat replacement, cabinet inspection, condensate maintenance, condenser cleaning, ventilation installation, indoor air quality, diagnostics, and the Chapter 20 capstone — depends on the system map produced here to correctly identify equipment, ducts, and components before any later work begins. Chapters 3 through 19 of this book are performed only on systems and components identified using this exact map.
Skills You Will Demonstrate
- HV-001 — Identify heating equipment by type, location, fuel or energy source, manufacturer, model, and visible service labels.
- HV-002 — Identify cooling equipment by indoor and outdoor components without opening the refrigerant circuit.
- HV-003 — Identify supply ducts, including plenums, trunks, branches, register boots, registers, and dampers.
- HV-004 — Identify return ducts, including return grilles, return boots, return trunks, and filter locations.
- HV-005 — Identify ventilation components, including outdoor-air intakes, bathroom and kitchen exhausts, dryer exhaust, and whole-house ventilation equipment.
- HV-006 — Create a basic HVAC system map showing equipment, airflow paths, controls, condensate, and unresolved conditions.
Where This Skill Fits
Every project in this book — from filter replacement in Chapter 3, to grille cleaning in Chapter 4, to duct inspection, sealing, and insulation in Chapters 5 through 7, to register, return, and flexible-duct work in Chapters 8 through 10, to balancing, thermostat, cabinet, condensate, and condenser work in Chapters 11 through 15, to ventilation, indoor air quality, and diagnostics in Chapters 16 through 19 — depends on correctly identifying the equipment, ducts, and components mapped here. A duct sealed, a filter replaced, or a breaker opened on a misidentified system is a hazard and a wasted repair.
The documentation habit established in this chapter — recording equipment, labels, photographs, and unresolved conditions — is the same discipline used for the shutdown and readiness record in Chapter 2 and the deficiency and diagnostic records required throughout the book.
Scope and Intended Use
This project covers:
- defining the exact system or zone included in the project
- identifying heating equipment, cooling equipment, air handlers, furnaces, fan-coil units, heat pumps, packaged equipment, boilers, radiators, or baseboards present, by type, location, and visible labels
- identifying visible supply and return duct paths, registers, grilles, filters, and dampers
- identifying visible ventilation, exhaust, and condensate components
- identifying thermostats, zone controls, disconnects, service switches, breakers, and equipment labels without removing restricted covers
- marking components whose function cannot be confirmed as unresolved rather than guessing
- preparing a schematic and existing-condition record and comparing it with any available drawings
This project does not authorize the learner to:
- open the refrigerant circuit or any sealed refrigerant component
- remove a restricted electrical, combustion, or equipment cover
- operate, adjust, or shut down equipment as part of this project
- diagnose, repair, or correct any observed condition beyond recording it for a later chapter
- proceed with any later chapter project when a condition identified in this chapter requires licensed inspection and has not been addressed
Any gas odor, scorch mark, damaged flue, suspected refrigerant leakage, electrical damage, or severe corrosion identified in this chapter must be recorded and escalated to a qualified professional; it is not corrected as part of this project.
Reference Conventions
Establish these references before beginning the system walk-through, and do not change the defined system or zone mid-project.
| Term | Definition |
|---|---|
| System or zone | The exact HVAC system, or the exact zone served by a defined portion of the system, that this project's identification and mapping apply to |
| Visible component | Any equipment, duct, register, grille, control, or condensate part that can be identified without removing a restricted cover, opening a refrigerant circuit, or operating equipment |
| Unresolved component | Any component whose function, connection, or condition cannot be confirmed by visual inspection alone, marked on the map rather than guessed at |
| Restricted cover | Any electrical, combustion, or refrigerant-component cover that this project does not authorize the learner to remove |
| Existing-condition record | The written and photographed record of equipment, ducts, ventilation, condensate, controls, and unresolved conditions produced by this project |
| Discrepancy | Any difference between field conditions and available mechanical plans, equipment schedules, or prior service records |
System Definition Record
Before beginning the walk-through, record the defined system or zone directly on the HVAC System Map and Existing-Condition Worksheet:
System or zone (address / unit / area served): ______ Heating equipment type: ______ Cooling equipment type: ______
Available plans or prior records: ______ (Yes/No, describe) Date started: ____________ Builder name: ____________
Prerequisites
- Available mechanical plans, equipment schedules, service records, owner information, or manufacturer labels for the system, if any exist
- Authorization from the property owner or responsible party to walk through and photograph the equipment, attic, crawlspace, and mechanical areas
- A defined system or zone that the assigned chapter project requires be identified and mapped first
- Safe, permitted access to the attic, crawlspace, basement, closet, or mechanical room containing the equipment
- 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
Every project in this book, from filter service in Chapter 3 to the capstone practice system in Chapter 20, depends on correctly identified equipment, ducts, and components. Learning to trace and document a system here, before any filter is pulled, any duct is sealed, or any breaker is opened, means every later project starts from a system you have identified rather than assumed.
Heating IDEquipment type, location, fuel or energy source, manufacturer, model, and labels identified
Cooling IDIndoor and outdoor cooling components identified without opening the refrigerant circuit
Supply-duct tracePlenums, trunks, branches, boots, registers, and dampers traced and recorded
Return-duct traceReturn grilles, boots, trunks, and filter locations traced and recorded
Ventilation IDOutdoor-air intakes, bathroom, kitchen, and dryer exhausts, and whole-house ventilation identified
Condensate IDDrains, traps, pumps, overflow devices, and discharge locations identified
Controls IDThermostats, zone controls, disconnects, breakers, and labels identified without removing restricted covers
DocumentationSchematic, existing-condition record, and discrepancy list completed for the defined system or zone
Restricted Covers, Refrigerant Circuits, and Unresolved Components
Every component identified in this chapter is identified visually, from accessible labels, nameplates, and observable routing. Do not remove a restricted electrical, combustion, or refrigerant-component cover, and do not open, cut, loosen, braze, or otherwise alter a refrigerant circuit at any point in this project. If a component's function cannot be confirmed without doing so, mark it unresolved on the system map rather than guessing.
HV-001 – HV-006
Identification / Documentation / System-Mapping Qualification
Identify and Document a Residential HVAC System
A. Finished-Project Specification
Quantity: one defined system or zone, identified equipment inventory, traced supply and return duct paths, identified ventilation and condensate components, identified controls and disconnects, completed schematic, and completed HVAC System Map and Existing-Condition Worksheet, with every unresolved component marked rather than guessed at.
B. HVAC Identification and Mapping Schedule
| Item | Target Condition | Verification Method |
|---|---|---|
| System or zone | Defined and does not change mid-project | Written record on worksheet |
| Heating equipment | Type, location, fuel or energy source, manufacturer, model, and labels identified | Visual confirmation and photograph |
| Cooling equipment | Indoor and outdoor components identified without opening the refrigerant circuit | Visual confirmation and photograph |
| Supply-duct path | Plenums, trunks, branches, boots, registers, and dampers traced and recorded | Visual trace and written record |
| Return-duct path | Return grilles, boots, trunks, and filter locations traced and recorded | Visual trace and written record |
| Ventilation components | Outdoor-air intakes, exhausts, and whole-house ventilation identified | Visual confirmation and written record |
| Condensate components | Drains, traps, pumps, overflow devices, and discharge locations identified | Visual confirmation and written record |
| Controls and disconnects | Thermostats, zone controls, disconnects, and breakers identified without removing restricted covers | Visual confirmation and written record |
C. Material Takeoff
- Documentation materials: one HVAC System Map and Existing-Condition Worksheet, one blank schematic sheet or grid paper.
- Field materials: labels or tags for marking unresolved components pending later identification.
- Photographic record: photographs of every equipment nameplate, duct configuration, ventilation component, condensate component, and unresolved condition.
D. Acceptance Standards
| Check | Standard |
|---|---|
| Equipment identification | Heating and cooling equipment identified by type, location, fuel or energy source, manufacturer, model, and visible labels |
| Duct tracing | Every accessible supply and return duct path traced from equipment to its termination or to the point access ends |
| Ventilation and condensate identification | Every accessible ventilation and condensate component identified and recorded |
| Controls identification | Every accessible thermostat, zone control, disconnect, and breaker identified without removing a restricted cover |
| Unresolved components | Every component whose function cannot be confirmed marked unresolved rather than guessed at |
| Documentation | HVAC System Map and Existing-Condition Worksheet complete with equipment, duct, ventilation, condensate, control, and discrepancy entries |
| Procedure | Heating identification, cooling identification, duct tracing, ventilation and condensate identification, controls identification, and schematic preparation completed independently and in sequence |
E. Preparation and Prior-Record Review
- Obtain available mechanical plans, equipment schedules, service records, owner information, and manufacturer labels. Record what exists and what does not before beginning the walk-through.
- Define the system or zone included in the project. State the exact system or zone in writing before proceeding to Step 3.
F. Heating and Cooling Equipment Identification
- Identify the primary heating equipment by equipment type, location, fuel or energy source, manufacturer, model, and visible service labels. Photograph the nameplate and surrounding installation.
- Identify the cooling equipment by indoor and outdoor components without opening the refrigerant circuit. Do not remove a refrigerant-line cover or access panel that exposes refrigerant components.
- Identify air handlers, furnaces, fan-coil units, heat pumps, packaged equipment, boilers, radiators, baseboards, or other system types present. Record every equipment type found, even if it is not the primary system.
G. Supply and Return Duct Identification
- Identify visible supply plenums, trunk ducts, branches, register boots, registers, and dampers. Trace each accessible supply path from the equipment plenum toward its termination.
- Identify visible return grilles, return boots, return trunks, filter locations, and return paths. Trace each accessible return path from the grille toward the equipment.
- Trace accessible duct routes and note changes in material, size, insulation, support, and condition. Record approximate duct sizes using the tape measure.
- Distinguish supply air, return air, exhaust air, outdoor air, combustion air, and natural building ventilation. Mark each traced duct or opening with its identified air type.
H. Ventilation and Condensate Identification
- Identify outdoor-air intakes, bathroom exhausts, kitchen exhausts, dryer exhausts, whole-house ventilation equipment, attic ventilation, and other ventilation components. Record the visible termination point of each, where accessible.
- Identify visible condensate drains, traps, pumps, overflow devices, and discharge locations. Record the visible routing and discharge point of each.
I. Controls Identification and Unresolved Components
- Identify thermostats, zone controls, disconnects, service switches, breakers, and equipment labels without removing restricted covers. Record the location and visible label of each.
- Mark components whose function cannot be confirmed as unresolved rather than guessing. Attach a label or tag where practical and record the location on the worksheet.
- Record equipment clearances, filter size, airflow arrows, service access, visible damage, corrosion, water staining, disconnected ducts, and blocked openings. Complete this record for every accessible area inspected.
J. Schematic and Existing-Condition Documentation
- Photograph representative components and labels. Confirm every equipment nameplate and each major duct, ventilation, and condensate component has a corresponding photograph.
- Prepare a schematic showing equipment, supply paths, return paths, ventilation components, controls, condensate, and exterior terminations. Use the blank schematic sheet or grid paper and label every component to match the worksheet.
- Compare field conditions with available drawings and record discrepancies. Note any difference between the schematic you produced and any available mechanical plans or prior service records.
- Identify conditions requiring licensed inspection, including gas odor, scorch marks, damaged flues, suspected refrigerant leakage, electrical damage, or severe corrosion. Record each condition and the recommended escalation; do not correct it as part of this project.
- Complete the final HVAC system map and existing-condition record. Confirm every field on the worksheet is filled in before authorizing later chapter projects to begin.
Common Readiness Inspection
Inspect every completed system map using the same checks regardless of which residence or training system the project involves.
- Heating check: confirm the heating equipment is identified by type, location, fuel or energy source, manufacturer, model, and visible labels.
- Cooling check: confirm the cooling equipment is identified by indoor and outdoor components without opening the refrigerant circuit.
- Duct check: confirm accessible supply and return duct paths are traced and recorded from equipment to termination or to the limit of access.
- Ventilation and condensate check: confirm every accessible ventilation and condensate component is identified and recorded.
- Controls check: confirm every accessible thermostat, zone control, disconnect, and breaker is identified without removing a restricted cover.
- Unresolved-component check: confirm every component whose function could not be confirmed is marked unresolved rather than guessed at.
- Documentation check: confirm the HVAC System Map and Existing-Condition Worksheet and schematic are fully completed.
Complete the HVAC System Map and Existing-Condition Worksheet in the Inspection Checklist section below before beginning Project 02.
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Failure Points and Troubleshooting
Cleanup
This project ends with the system map completed and the work area left undisturbed, not altered further until the assigned project begins.
- Confirm all photographs are labeled and stored with the worksheet
- Confirm every access panel, attic hatch, or crawlspace cover opened for inspection is closed and secured
- Confirm labels or tags applied to unresolved components remain in place
- Store the tape measure, flashlight, and camera in a protected, undamaged condition
- Store the HVAC System Map and Existing-Condition Worksheet and schematic for reference by later projects
Field Terms
- System or Zone
- The exact HVAC system, or the exact zone served by a defined portion of the system, that this project's identification and mapping apply to.
- Visible Component
- Any equipment, duct, register, grille, control, or condensate part that can be identified without removing a restricted cover, opening a refrigerant circuit, or operating equipment.
- Unresolved Component
- Any component whose function, connection, or condition cannot be confirmed by visual inspection alone, marked on the map rather than guessed at.
- Restricted Cover
- Any electrical, combustion, or refrigerant-component cover that this project does not authorize the learner to remove.
- Existing-Condition Record
- The written and photographed record of equipment, ducts, ventilation, condensate, controls, and unresolved conditions produced by this project.
- Discrepancy
- Any difference between field conditions and available mechanical plans, equipment schedules, or prior service records.
- Supply Path
- The airflow route from equipment plenum through trunks, branches, and boots to a supply register.
- Return Path
- The airflow route from a return grille through boots and trunks back to the equipment, including the filter location.
Skill Check
- Why must equipment be identified from visible labels and observable routing rather than from assumptions based on size or appearance?
- What must the learner do when a duct or component's function cannot be confirmed by visual inspection alone?
- Why does this project not authorize opening the refrigerant circuit or removing a restricted electrical or combustion cover?
- What conditions observed during the walk-through require the learner to stop mapping an area and escalate rather than continue?
- Why must supply air, return air, exhaust air, outdoor air, and combustion air be distinguished rather than treated as one airflow category?
- What hazards must be checked before entering an attic, crawlspace, or mechanical closet for this project?
- What information must be recorded on the HVAC System Map and Existing-Condition Worksheet before a later chapter project may begin?
- Why must a discrepancy between field conditions and available mechanical plans be recorded rather than resolved by editing the schematic to match the plan?
- Why must the system or zone be defined in writing before equipment identification begins?
- Why does this project not authorize diagnosing, repairing, or correcting an observed deficiency?
Competency Rubric
| Competency | Independent Pass Standard | Not Demonstrated | With Assistance | Independently |
|---|---|---|---|---|
| HV-001 | Identifies heating equipment by type, location, fuel or energy source, manufacturer, model, and visible service labels | |||
| HV-002 | Identifies cooling equipment by indoor and outdoor components without opening the refrigerant circuit | |||
| HV-003 | Identifies supply ducts, including plenums, trunks, branches, register boots, registers, and dampers | |||
| HV-004 | Identifies return ducts, including return grilles, return boots, return trunks, and filter locations | |||
| HV-005 | Identifies ventilation components, including outdoor-air intakes, bathroom and kitchen exhausts, dryer exhaust, and whole-house ventilation equipment | |||
| HV-006 | Creates a basic HVAC system map showing equipment, airflow paths, controls, condensate, and unresolved conditions |
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 — HVAC System Map and Existing-Condition Worksheet
| Item | Target Condition | Result | Pass/Fail | Correction (if any) |
|---|---|---|---|---|
| System or zone | Defined in writing before equipment identification began | |||
| Heating equipment | Identified by type, location, fuel or energy source, manufacturer, model, and labels | |||
| Cooling equipment | Identified by indoor and outdoor components without opening the refrigerant circuit | |||
| Supply and return ducts | Traced and recorded from equipment to termination or to the limit of access | |||
| Ventilation and condensate | All accessible components identified and recorded | |||
| Controls and disconnects | Identified without removing a restricted cover | |||
| Schematic and discrepancy record | Completed and compared against available plans |
Unresolved components and escalation notes: ____________________________________________
System map declared ready: ______ (Pass/Fail) Date: ____________ Builder name: ____________
Performance Check
With the heating and cooling equipment identified, supply and return duct paths traced, ventilation and condensate components identified, controls and disconnects identified, unresolved components marked, and the schematic completed, review the finished system map against the Acceptance Standards table and confirm the equipment is identified by type, location, fuel or energy source, manufacturer, model, and labels, every accessible duct path is traced to its termination or to the limit of access, every accessible ventilation and condensate component is identified, every accessible control and disconnect is identified without removing a restricted cover, every unresolved component is marked rather than guessed at, and the schematic and discrepancy record are complete. Complete the HVAC System Map and Existing-Condition Worksheet and correct any failed item before beginning Project 02. If an item fails, identify whether the error occurred in equipment identification, duct tracing, ventilation or condensate identification, controls identification, or documentation before correcting it and re-running the affected check.
Project Closeout
You have completed the first project in the residential HVAC sequence: identifying and documenting a residential HVAC system. This project required you to identify heating and cooling equipment, trace supply and return duct paths, identify ventilation and condensate components, identify controls and disconnects without removing restricted covers, mark unresolved components, and complete a documented system map and existing-condition record (HV-001 through HV-006).
You now have a verified system map and existing-condition record you can reference for every later project. That record carries directly into the next project: shutting down and preparing this same system's work area using the identified equipment, disconnects, and hazards recorded here.
Retain your HVAC System Map and Existing-Condition Worksheet and schematic. You will reference this exact identification record before every project in the rest of this book, beginning with the shutdown and readiness procedure in Chapter 2.