extractor fan rubber mounting kits

[Fred]

Hi,

I have read here about using some sort of rubber mounting when you fit an extractor fan, so that the vibration of the fan doesn't shake the wall/ceiling it is mounted on, transferring the noise. The problem is I don't know the correct name for these rubber fixings, so google is not my friend. Can anyone tell me what they are called and where to get some?

TIA

[Alan]

In message , Fred wrote

Not the cheapest but once you can identify some key words search Ebay etc.

Example from a 2 Ebay second search

[geoff]

In message , Fred writes

Typing "Anti vibration mounts" into google will bring endless hours of fun for you to while away those summer evenings with

[NT]

Tap washers. Dont forget to use 2 per fixing screw, one each side of the fan case plastic.

NT

[DaveN]

For want of better materials to hand, I made a 40cm-square 'mounting table' for a fairly big loft extractor fan by sandwiching four foam scouring pads between a couple of pieces of 18mm chipboard, all held together with hot glue. It works fine - the fan is sitting on top of a ceiling joist, and is inaudible in the bathroom beneath.

I haven't had so much success with rubber isolators. Alternating materials of high and low stiffness in a sandwich is how some 'proper' vibration isolators work.

I think the other trick for a loft fan is to hang it on a loop of nylon string at each end, suspended from the roof structure (not in mid-air, just so it doesn't touch anything which will conduct the sound).

Dave

[NT]

do consider longevity of materials.

NT

[Chris J Dixon]

These can reduce conducted noise, though it is always possible that you might create a system which has a resonance in the frequency band(s) the extractor produces. What you will not do is reduce air movement noise.

Chris

[geoff]

Its what he asked for

and ...

strangely enough, its what they use in e.g. warm air fans just for the purpose

[Fred]

Thanks. I may try the tap washers before looking for anything else as they will be easy to get hold of. BTW, when was the last time anyone changed a tap washer? I can't remember having to.

[NT]

Also theyre very long lasting, which is important.

NT

[Fred]

Yes, it was noise conducted through the wall that I was trying to avoid. Any noise of the air on its way through the ducting, I hope will be minor in comparison and I can live with that. Thanks.