Extractor fan noise and vibration

[themoo]

I have moved into a ground floor flat. There was an extractor fan in the bathroom but it only went on and off when the light went on & off, so I asked my electrician to fit a new one which he did. The fan is very quiet but my neighbour upstairs complains of vibration through the walls. The electrician loosened a few screws which reduced the vibration yesterday and the neighbour was happy, but I had a bath last night and shower this morning. Now the neighbour is saying it's still vibrating and is very noisy. I don't know what to do to make this better. The fan is in the same place as the previous one and he didn't complain about that. Please can anyone help? He is a nice guy and I don't want to disturb him but I also need to be able to use an extractor fan! Thank you.

 

[BIGbadmarky]

You need to isolate the new fan from the structure of the building to stop the transfer of energy in to the walls. Does the fan manufacturer have any proprietary equipment for resiliently mounting the fan? Failing that, maybe look at some rubber grommets or something. You need a material which will deform enough to isolate the fan but not allow the fan to wallow around when operating.

Was your old fan attached with any isolation mounts? Your neighbour might have had an issue with the old fan but not had the stones to discuss it with the old occupant.
Cheers,
BBM

 

[themoo]

Thank you for your reply. I don't think it was as they seem to have done a rather botched job with it hence I thought if anything this one would be better! The electrician recommended some weatherstrips from Screwfix; is that the kind of thing you mean?

 

[JohnD]

please post a pic of the fan, and how it is attached.

 

[themoo]

After much fan-nying around it appears to be that the case for the fan is vibrating against the wall. When I removed the case the vibration was much reduced. Obviously I can't use it without a case but hopefully I can put the weather strips on it?

 

[denso13]

Obviously I can't use it without a case but hopefully I can put the weather strips on it?

Worth a try.

 

[JohnD]

I suppose the wall is not flat, so tightening the screws distorts the case.

If you can puzzle it out, you might be able to tighten two or more screws where the case meets the wall without distortion, which should hold it steady enough not to vibrate, and pack rubber sealant strip to seal all round.

it's possible that the duct in the wall is not at 90 degrees to the wall, so that you can't have both the spigot and the backplate tight. You might see this if you undo the screws and gently pull the fan out of the duct.

Some modern fans have slightly larger spigots than old ones, and will not fit freely in an old duct.

I had this, and had to slit the duct with a multicutter and pull part of it out. It was a tiresome job.

There are a few high-quality fans with ball bearing motors mounted in flexible rubber blocks, which are very quiet. If you don't mind changing your existing fan, which is listed as
• Airflow: 88m3/h, 24L/s.
• Sound:32dBA at 3m

you can get a better one; quieter and more powerful.
.

 

[themoo]

Thanks again for your replies. I have stuck a load of weatherstrips underneath the fan casing and my neighbour seems a lot happier. Tomorrow morning (it wakes him when I have a shower) will be the crux, but I have it on at the moment and he said he couldn't hear it at all. Fingers crossed! I would in time get a more expensive fan, but I must say I am a bit sick of spending money I don't have on it at the moment.

 

[themoo]

Thrilling fan update: all sorted! Neighbour very happy. Thank you all for your help.