alternative to sorbothane washers? (vibration control)
 

So I want to install an attic vent fan in my house (1600 s.f.). I bought one for $88. I've done this in my old house, but didn't like the noise transmitted to the frame. I could hear it in the house.

So this time I want to mount it with rubber washers. I thought, well, Sorbothane should work great! Um, $30 worth of rubber washers to mount an $88 fan:


http://ecx.images-amazon.com/images/...XL._SX522_.jpg

Would regular rubber work as well?
Does anyone know a cheaper source of Sorbothane washers?
Why are they so pricey anyway? Active patent?

Cable grommets, like for through a firewall?

I've used these at work with positive results. Not much cheaper i guess...

McMaster-Carr

McMaster has a pretty big selection of vibration reducing washers. I've also used specialty rubber isolators that you cut dow to your own desired thickness. But now i can't find it. Maybe i bought it off ebay.

Edit* This fan has 8 mounting points?

McMaster-Carr


These are excellent. They'll absorb your vibrations.

What vehicular posted. I have used them with amazing results.

Thanks for the ideas. I went and got these from ebay:
Set of 4 Universal Vibration Mount Isolator 3 4" | eBay

Also consider a mass damper. I made one for a valve grinding machine I built a while back, just used 10% the mass of the system, glued it to a piece of rubber and glued the rubber to the system. Very nice level of dampening and super easy to do in my case. Also did rubber feet too

The project is done. I'm quite pleased with the results using the eBay isolators I linked.
From inside the house under the fan, the cat fountain pump is louder.

https://www.miataturbo.net/attachmen...ine=1423257732