My FHA heating duct in the basement of a rental unit is pretty noisy with a vibrating, rattling sound. The ducts seem to be tight to the ceiling joists but if you push on the bottom of the duct the rattle stops. Any idea what could cause this rattling? I was thinking that maybe something is inside the duct, like a metal screw (that’s kind of what it sounds like) and was considering cutting a hole in the bottom of the duct to clean it out, then patch it with an sheet metal patch. Is that as bad an ida as it sounds? Befofe I did that I’d like to eliminate other possibilities.
Thanks,
George
Replies
How's it hung? tabs or straps?
And is there a flexible boot at the furnace/duct connection?
If strapped, shove a shim in there to see if it just needs a bit of tightening.
Couplers might also rattle (doubtful), but can be shimmed to find out.
Flip dampers usually can be tightened (if that's the source). Tighten the nut.
I doubt that it's something loose inside -- for that to be the case the amplitude of the vibration needs to be above 1 G, and that's more motion than you'd typically see in a duct that wasn't directly attached to the air handler.
I would guess that it's "just vibration", perhaps the duct rattling against something next to it or above it, or simply microscopic "oil-canning". See if you can jamb something up next to the duct to stop the rattle. Or, as I've done in some cases, you can glue something like scrap vinyl flooring or self-stick floor tile to the duct to dampen it.
Something perty like pink with red roses would be nice.