Trace each duct run, air handling unit, and terminal unit from the mechanical schedule into its equipment category, duct pressure classification, and fire or smoke damper rating, then confirm sound attenuation and testing references before treating the drawings as complete.
Assemble the review package
Gather the mechanical equipment schedule, ductwork plans with pressure-classification notes, the life-safety or rated-wall plan for damper locations, terminal-unit schedules, and the issued HVAC air distribution specification. This single section now covers what used to be separate ductwork, air handling unit, and terminal unit sections; review one system or zone completely, since a general note copied across the set may not carry the correct equipment category with it.
WBDG publishes UFGS 23 30 00: HVAC Air Distribution as a public guide-specification reference (accessed September 26, 2026). Use your project’s issued specification and amendments for the actual comparison; the guide specification does not automatically govern your project. The checklist below is an original suggested review workflow, not a reproduction of the UFGS requirements.
Eight checks to run against the issued set
Use one record per location or system. The CSV contains the same eight prompts plus fields for source revisions, observed evidence, the review owner, the decision, and closure references.
| Check | Sources to compare | Question to resolve |
|---|---|---|
| Equipment category assignment | Mechanical schedule tag + specified air handling unit, terminal unit, or fan category | Does the scheduled equipment resolve to a defined category — field-fabricated or factory-fabricated air handling unit, VAV or dual-duct terminal unit, fan-powered terminal unit, room fan-coil unit, or unit ventilator — rather than a generic “AHU” or “box” label? |
| Duct pressure classification | Ductwork plan pressure note + specified ANSI/SMACNA 006 construction and sealing requirement | Does the drawn duct pressure classification match the construction gauge and joint-sealing method the specification requires at that classification, including at points where the classification changes? |
| Fire and smoke damper rating | Life-safety/rated-wall plan + specified fire damper rating default | Where the drawings do not specifically call out a 3-hour rated fire damper, does the rated-wall plan confirm the specification’s 1.5-hour default is actually adequate for that wall, rather than the omission being an oversight? |
| Pressure relief at fire dampers | Ductwork plan + specified pressure relief door requirement | Where rapid closure of a fire damper could over-pressurize or collapse the attached ductwork, does the plan show the pressure relief door the specification calls for at that location? |
| Sound attenuation basis | System total pressure + specified sound attenuation equipment for systems above or below 1 kPa (4 inches water gauge) | Does the specified sound attenuation equipment match which side of the 1 kPa (4 inch water gauge) threshold the system’s actual total pressure falls on? |
| Terminal unit component completeness | Terminal-unit schedule + specified primary damper, flow sensor, and reheat coil type | Does the schedule identify the primary VAV damper or valve, flow sensor, and reheat coil type (hot water, steam, or electric) consistent with the heating source actually available to that unit? |
| Security diffuser and register selection | Room security classification + specified security ceiling diffuser or register option | In a detention or high-security space, does the schedule call out the specified security diffuser or register option rather than the standard type used elsewhere on the same sheet? |
| Testing and balancing cross-reference | Specified duct leak test and TAB reference + issued document set | Since ductwork leak tests, damper acceptance, and testing/balancing are specified in a separate testing-and-balancing section, is that section actually included in the issued set the review is comparing against? |
Worked example: a corridor wall without its rated fire damper
Illustrative example: a duct crossing a corridor wall is scheduled with a fire damper, but neither the drawings nor the specification edit specifically call out a 3-hour rating for that wall. The specification’s own default supplies a 1.5-hour rated damper unless a higher rating is specifically indicated, so the corridor wall’s actual rating needs to be confirmed before the default is accepted.
Check the life-safety or rated-wall plan for the corridor’s actual fire-resistance rating, confirm whether the 1.5-hour default damper is adequate or a 3-hour damper needs to be specifically called out, and recheck the pressure-relief-door requirement at the same penetration before closing the item.
Avoid a false conflict
A duct or terminal unit shown correctly on one sheet does not confirm every similar-looking piece of equipment elsewhere in the schedule shares the same category, pressure classification, or damper rating; this section now covers equipment that used to sit in several separate sections, so a generic label is more likely to hide the wrong category than before.
When requirements disagree, follow the project’s document-control and clarification process. Do not assume that drawings always override specifications, or the reverse. Identify the exact sources and request an authorized decision.
Close the issue across the affected documents
Record the location or tag, drawing and specification references, issue dates, observed difference, and the decision needed. Assign an owner and keep the item open until the response identifies the governing requirement. Check the revised drawings and specification references together; a response email alone may leave the issued package inconsistent.
For the overall process, use the guide to drawing and specification conflicts. Mark an inapplicable checklist row with a reason, and distinguish a verified correction from a question that still needs design information.
Where Groundbook fits
Groundbook’s drawing and specification review helps investigate potential disagreements in the documents you supply. Include the relevant specification sections and drawing references, then verify the cited evidence with the responsible reviewers before acting on a finding.