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.
Do not leave a sound attenuator reversed just because the bolt pattern matches.
Check
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.
Steps
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.
Say this to your 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?