Static field route #19093

What do I do when a sound attenuator is installed backwards?

Equipment Connections: RTU, AHU, VAV, Fans & Louvers⚠️ CHECK BEFORE YOU FIXV191 answer-gap expansion

📖 Verified core answer

Many sound attenuators are directional. Match the airflow arrow/submittal orientation before final connection so the baffles do not create extra pressure drop or noise.

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Field verification checklist

Find the airflow arrow or manufacturer label on the attenuator.
Confirm actual system airflow direction from drawings and duct path.
Check whether baffle noses/tails are oriented per submittal.
Verify hanger support before dropping or rotating the unit.
Recheck gasket, flange alignment, and clearance after reinstall.

Ask foreman

The sound attenuator at [location] appears reversed compared with the airflow arrow. I checked the duct direction and tag. Do you want it dropped and spun before final connection?

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 leave a sound attenuator reversed just because the bolt pattern matches.

Why this matters

Reversed acoustic equipment can create unnecessary pressure drop, turbulence, noise, and balancing problems.

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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