ventilation fan vibration isolation help needed


I will be putting two exhaust and one injection fan in my cabinet to properly move air. Two will be mounted horizontally and one veritically. The trick is that I work so hard to get the cabinet isolated from vibrations that by adding a fan, I'm added micro vibs to the cabinet. The fans are 4" radio shack fans running at 6 volts instead of 12volts in order to slow them down and reduce noise yet still move air. I was planning on using placing a sorbothane grammet (if I can find some) around the screw that is screwed into the cabinet and it would hold the fan about 2mm off the cabinet. Any other suggestions. I want to keept it simple but yet very effective. Thanks Troy
troy_noel
I have done exactly what you are doing and tried several approaches to mounting the fans. If you make any kind of direct connection to the cabinet, it tends to amplify the noise of the fan and pick up the vibrations. What finally worked best was to use Velcro! While the fan is not rigid to the touch, it stays in place and can't be heard.
One simple solution is to glue a sheet of Dynamat on the cabinet wall, cut a hole big enough for the fan, and mount the fan on the dynamat. You can also glue Dynamat on any cabinet surface to damp its vibration, very effective. Take a look at their web site www.dynamat.com for more details.

BTW, Some Dynamat products are heavily discounted at Amazon.com.

Try Herbies audio labs and get the isolation devises he puts on the tube dampers as I think he sells them seperately, then I would install only exhaust fans away from any openings (doors, etc.) as I would think you would want the cool air pulled into the cabinet through the non sealed openings, across components then exit via the fans. Maybe one at each end on the sides of the cabinet.
Try Velcro. It's little hooks and loops make a perfect isolation barrier for the light hanging fan.
Isolation techniques are all well and good, but how about using some really good fans to start with (i.e. not RS crap)? I recommend Pabst, the original "whisper fan" they're so quiet and vibration free you won't even know they're there. It sounds like you already put in a lot of time and effort, so don't "cheap out" now!

http://www.ebmpapst.us/

There are many suppliers. Type:

pabst fans

into Google search.
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My suggestion is to start with the quietest fan you can get and I don't think Radio Shack fans are the best in that area. The quietest fan I have found is a fan by the name of Vantec Stealth available from nexfan.com. It comes in several sizes and is relatively inexpensive. Additionally, I found that the advice from Jsawhitlock above is spot on as well.
Look for Nexus fans.

The quietest mounts I have used on my computer are these fan mounts:

http://www.endpcnoise.com/cgi-bin/e/std/sku=Fanisolators.html

I think they are available at many online computer stores, as well as McMaster-Carr.
When I added a fan in my old cabinet I went through a bunch of different ideas. The best by far was to hang the fan from the shelf above with cord, so that it gently blows over the top of the ewuipment. Then get a dimmer switch and connect it to the fans so you can turn them down and reduce the noise factor from them.

You really don't need much air movement to cool things down. A little goes a long way, as long as there is some ventilation in the cabinet. I used to crack the front door open a wee bit when playing music.

Enjoy,
Bob
Thanks everyone for your help. You've given me some great ideas and the resources of where I can get the correct equipment. Thanks again, Troy