Static field route #19099

What do I do when back-to-back offsets feed directly into a VAV inlet?

Airflow/TAB Impacts From Installation⚠️ CHECK BEFORE YOU FIXV191 answer-gap expansion

📖 Verified core answer

Back-to-back offsets at a VAV inlet can spin and disturb the airflow before the sensor. Give the VAV a smoother approved inlet path instead of dumping turbulence into the box.

Open in Field Rescue Open category

Field verification checklist

Identify all offsets/flex bends immediately upstream of the VAV.
Check whether the box has unstable readings or noise.
Confirm manufacturer/submittal inlet requirements and coordination drawings.
Measure space for a smoother rigid inlet or box shift.
Get foreman/detailer direction before rerouting.

Ask foreman

VAV [tag] has back-to-back offsets right at the inlet and TAB readings are unstable. I checked the obstruction and inlet path. Do you want a smoother rigid spool/offset or box shift?

Text to foreman

Route options

AMake the field correction only if it is within your assignment and the approved method.

BHold and document the condition if the fix affects airflow, access, life safety, pressure class, rated assemblies, equipment, or another trade.

CBring the foreman/detailer the location, what you checked, and what decision you need before cover, startup, or rework.

Do not do this

Do not pile sharp flex offsets directly onto a VAV inlet and expect the flow sensor to read clean.

Why this matters

Bad inlet air profile creates erratic CFM readings, balancing problems, and comfort complaints.

Final verification

Use this as field training guidance. Final direction still comes from the foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements.

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