Static field route #19076

What do I do when a fan coil is hard-connected and vibrating the ceiling grid?

Equipment Connections: RTU, AHU, VAV, Fans & Louvers✅ STANDARD FIELD CORRECTIONV190 answer-gap expansion

📖 Verified core answer

A fan coil or fan-connected unit hard-piped to duct can transmit motor vibration. Add the approved flexible connector/isolation detail and make sure the duct is independently supported.

Open in Field Rescue Open category

Field verification checklist

Confirm the vibration source is the unit, not loose ceiling, hangers, or duct rubbing.
Check whether a flexible connector/isolation detail is shown on the submittal/drawings.
Make sure ductwork is independently supported and not hanging from the unit collar.
Check connector material, slack, alignment, and access.
Recheck vibration/noise after startup.

Ask foreman

This fan coil/unit is hard-connected to duct and vibrating the grid. I checked supports and the submittal detail. Do you want a flexible connector/isolation break installed at the discharge/return 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 use the rigid duct connection as the vibration isolator.

Why this matters

Hard connections can spread motor hum, loosen joints, crack sealant, and create noise complaints after occupancy.

Verification basis

Approved drawings/specs, project coordination drawings, manufacturer instructions/submittals, shop standards, foreman/detailer direction, employer policy, and AHJ/code requirements.