I'll offer some suggestions to get this conversation rolling. Sometimes it helps attract interest to get a few responses listed under your topic.

I don't know about Faber hoods, but I have seen a couple of things "like that."

Once in a while, I experience something like you describe but it only happens when I'm also running the oven convection fan while we have strong, gusty winds from one specific direction that creates a vortex between my house and my neighbors' and seems to push against and affect the exterior vent-cap and impede the exhaust. We rarely get that kind of wind and your description doesn't mention any environmental factors, so this info is probably of no help to you. But it does suggest that you check to be sure that the exterior venting is working properly, if that already has not been done.

Next thing I would want to figure out is if you have an installation problem or if the problem might be a defective hood or if it might be a combination of the two.

if you feel the vibration when you put you hand on your hood while it is running, you want to find out if other Faber hoods do that. Have you called Faber to find out if their hoods vibrate? I don't know if the fan mounting in the hood is a bit loose or if it is supposed to have vibration dampers (and maybe they got left off), but that is worth checking. Also, Is there a store near you with one of these hoods installed? If so, run the hood in the store and put your hand on it. If you do not feel the same vibration, then you may have a defective or loose unit or maybe a bad bearing on the fan shaft.

You mention asking your contractor to recheck this. Are we talking about a newly built house or just a kitchen remodel or maybe just somebody hired install the hood? I ask because you say "it is all wood and drywall here." If it is an older house and the vent hangs on an interior wall, the stud bays may be empty. Empty stud-bays can act like a drum ("resonance chamber") which amplifies the vibrations from the hood. If your hood is cabinet-hung, then the cabinets could be combining with the walls to produce that, as well.

Your contractor could try some vibration damping material between the cabinets and the hood if you have a cabinet hung hood. If it is a wall hung hood, you might try remounting the hood to a 3/4" piece of plywood (which would require some futzing to get your ducting to line up correctly.) The plywood would help deaden some of the vibration.

Another thing to check is the ducting itself. Were the joints and seams taped so they don't leak? If not, they could be vibrating. Is the ducting buried in a wall where you can't get at it easily?

There also may be baffle ("flapper") at the top of the hood. Where I live in Montana, we want to keep cold air from backflowing through the ducting into the house, so hoods generally have "flappers" at both the hood and at the outside wall. I've seen one instance where a loosely mounted "flapper" vibrated pretty badly, although those vibrations didn't transmit to the floor.

With these comments, hopefully somebody more knowledgeable will jump in with better advice.

This post was edited by JWVideo on Wed, Sep 25, 13 at 13:36