I have a VAH. I think it's loud too and only use it when absolutely necessary. We have a small TV in the kitchen and when the VAH is on you can't turn the volume loud enough to hear it over the fan noise - and I have a relatively small kitchen so I'm pretty close to the TV. I think it's normal for these hoods to be loud just that some people find the level of noise to be acceptable and others, like me, can't stand it.

It depends on the duct length, number of bends, and other factors but yes, in general, hoods make noise. My hood has 3 settings and the lowest setting is what I consider to be quiet but you can hear it. When I go to medium or high it gets reasonably loud. I tend to use it on low when I can but do crank it up when necessary.

OK, you guys are making me feel a little better. Thank you for your responses.

Even the lowest setting is quite loud (compared to the dinky Broan we used to have with our electric range) so I hope I will actually use it and not wreck my new cabinets with steam because I don;t turn on the noisy hood!

I may call Thermador and see if they will send a tech to look at it, just to make sure there's nothing actually woring with it. Do you think thats a good idea?

The noise level is measured in sones. The higher the number, the louder the hood. You may want to check your specs to see what the sone level is. I have a range hood which is 695 cfm's and is 5 sones. It's pretty quiet compared to my old hood.

How many CFMs? How large is your duct? How many turn does your duct have? How long is your run?

Is the noise more "rushing air" or is there a mechanical component that you're concerned with?

All in all, a hood should not be quiet except on low. But it should not be " SOOO loud" either unless there are significant problems with the venting run or you just purchased a unit that isn't that quiet.

Yes, I was surprised at how loud my hood is when it is on hight, but I think it is normal. I am more used to it now. My range is all the way across the room from the eating area, and I'm glad. We had toyed with having the cooktop right across from the eating area, which would have been nice to be able to speak to people at the table as I cooked, but now I'm glad I didn't do it, because it keeps the noise away.

OK, we did some more research and there's clearly a problem.

On the appliance forum theres a good vent blower overview that states that the majority of the sound from the hoof should be airflow, and the secondary component of the sound is the motor.

In our case the majority of the sound seems to be from the motor.

1) The ducting installation is very clean. One 90 elbow and then a straight 5-foot shot to the roof cap. Solid ducting, very well secured.

2) We turned the blower on BEFORE any ducting was installed or filters in place. The sound was atrocious. After ducting hooked up and filters in place, sound was exactly the same. It seems in a normal situation, the increased airflow resistance of ducting and filters should have INCREASED the noise level. On this case it did not. I suppose it could be the airflow over the ventilator motor's blades? (It is a dual-blower model.)

3) Even on the lowest setting, you can feel the floor and cabinetry around the range vibrating slightly. On high the vibrations are easy to feel. That doesn't seem right.

4) I cannot find noise level specs for our model (discontinued model). But other hood manufacturers and even other Thermador models have specs such as 2.0 sones to 6.5 sones, low-high. Where one sone is roughly the equivalent of a refrigerator, 4 is normal conversation, 8 is city traffic. Although of course it's subjective without a meter of some sort, I would say we've got about 6+ at low and well over 8 at high.

We talked about getting a remote blower. perhaps that would help. But it seems like maybe it's actually a problem with the motor itself....?????

I am going to call Thermador tomorrow. I really hope they will honor the warranty and send someone out to look at it!

"2) We turned the blower on BEFORE any ducting was installed or filters in place. The sound was atrocious. "

VERY smart move! And this will save you enormous grief and allow you to get the problem fixed as easily as possible.

Don't know if it's possible, but two 45's would be quieter than one 90 elbow, and if you're transitioning from round duct to square (or the reverse), the place to do it is in the turn.

Thanks sweeby. The trasition (from 3.5 x 18 to 8" round, a special Thermador piece of course) comes directly off the motor -through the wall- and then into the 90* elbow and straight up.

However, as noted the sound was the same before ducting was attached, so it probably wouldn't help us appreciably to change to to 45s...

Our vent was way too loud when first installed, and it turned out that there was some kind of vibration problem from the installation, and we got that taken care of. That being said, it is still louder than I expected it would be.