Radiator Fan noise
 

Im using 2 Panaflo L1A on my heatercore (shrouded) and am having a real problem with the noise of the air going through the core. The 2 fans running on their own are very quiet, but the moment I stick them on the shroud they get very loud.

Is this a problem due to the fins being too close together or that some are bent maybe? Or its normal for a fan's noise level to sky rocket when using them on the rad?

Yes.
You can limit this by dampening fan mounts (use rubber silentblocks), decoupling the fan casings from the shrouds (neoprene for example), of course *use* shrouds.
That way vibrations will not propagate through the heater core.

One other thing that I am going to try is to use sandpaper on the fan blades themselves! I read in one of my junk mails that I got that if you use 400grit sandpaper and sand down the edges of the blades that it can make a difference in how loud the fans are.

It MAY work, It my NOT work. I am going to give it a shot since I am going to have my entire PC torn to bits here soon and I would like a little less noise from my 108cfm fan @42dbls :(

Sanding the fans works, but dont expect too much. I sanded my 120 mm sunons with 400 and 600 grit paper and it took too much patience and nerves if you don't want to disassemble the fan. Just use exacto knife (scalpel) to carefully remove all remains of the molding in fan case and impeller, than sand all with some or none pressure with the paper. The thing is that you must pay attention not to disbalance the impeller.
It's much easier if you disassemble the fan and take the impeller out.
I removed all sharp edges on the impeller and smoothed fan case, than filled the row holding the wires with hot glue gun.

In the end, sunon working on 7 V WAS quieter, but not enough (it's a Sunon!).

Dunno if that is worth the effort, but the fun part is doing it...:D

Try and see (hear):p

btw, what payment method did you use when ordering tygon from BECooling (its www.aquastealth.com right?), and just for my info, how much money for sh+h?

thx.;)

I like my panaflos still:) They remain the best in terms of cfm/noise. Just finished reinstalling my shroud with rubber washers under the foam, and its a little better....

My only next option is to get some of the noise dampening matrial that you stick to the inside of your case and put it everywhere, although I dunno how much good that will do considering I have a window.

Use this link to get to BECoolings shopping area:
Payment method was just with a standard credit card; nothing special.
My shipping and handleing was somehting like $5.95 for ground.
The tygon was the most expensive thing; over $20 worth of tubing.

http://becooling.safeshopper.com/

Yes Aquastealth is the same place.

BTW thanks for the confirmation on the sanding of fan blades. I wasnt expecting a miracle but just something to tone the noise down a bit. Mines a Sunon too and if I could cut the noise down to 40dbls that would be great.

Not quite. Check out this link:
http://www.silentpcreview.com/module...rtid=25&page=1
(last news, they're getting an anechoic chamber to do noise measurements !!!)

NBM Tech, PAPST are the best compromise. PAPST fans are a bit more expensive out here, but quality comes at a price...

It will do next to nothing, save your money.
Read that article:
http://www.twistedmods.com/modules.p...icle&artid=172
The best method to silence things is:
- buy elements which are *already* silent
- decouple them, to avoid noise propagation
- insulate them (in the case of HDDs)
- get rid of fans !

Thx for the info on BECooling Jtroutma!

One thing comes to mind, the goal with sanding fans is to smooth the surface and gain less hiss of the air being pushed through the fan. Maybe you could try to lacquer the fan parts in one or two thin layers to fill the gaps (in the end, same thing you get with sanding). Two thin layers should do the trick and would not add much mass to the impeller.

Think that I'm gonna try it once my tygon arrives (thx again for link), and I dismantle my system for tube change...