Ball vs Sleeve Bearing

dazzerd · 25 May 2010 at 20:22

Hi I am currently looking to replace my 3 120 m sharkoons on my pa 120.3 which is mounted horizontally at the top of my 700d.

After doing some research it seems like sleeve bearing fans should not be mounted vertically, i.e. blowing air up or down. This was news to me as my sharkoons have been mounted that way for a long time. Allegedly any reduction in noise which would normally be accounted for by using a sleeve bearing fan can be negated by not mounting them horizontally, i.e. they should be blowing left or right.

As most silent fans seem to be sleeve bearings has anybody any experience of using ball bearing fans in a vertical position on a pa 120.3. If so which ones?

Sorry after reading more it seems that rifle bearing fans or fluid bearing fans may be the quietest and best suited fans for rads. Do these even exist for pcs?

cheers

Ordokai · 25 May 2010 at 20:39

Selecting (or not) a fan for it's bearing alone is silly, regardless of positioning. The differences between fans even of the same type are substantial, you get loud and quiet fans in all categories. It's mostly the fin design, motor and size of a fan that determine its sound pressure profile, the bearings themselves play a minuscule role because they're all designed specifically to interfere with rotation as little as possible.

These three links here, here and here may be of relevance. Granted, not all of the covered fans are available here, nonetheless trends and tendencies can be readily seen across differing designs.

- Ordokai

liquidex · 25 May 2010 at 21:15

Good fans for rads using ball bearings are the Scythe Gentle Typhoons. Also The Scythe S-flexes as they use fluid dynamic bearings (FDB). Here is another round up of fans used on a rad.

http://www.madshrimps.be/?action=getarticle&articID=936

Ordokai · 25 May 2010 at 21:34

liquidex said:
[snip] http://www.madshrimps.be/?action=getarticle&articID=936

The exact same information as my first link, only better presented and paced. Neat, nice find.

- Ordokai

dazzerd · 25 May 2010 at 21:52

Thanks guys really useful information.

Ordokai, I realise that basing a decision on fan type maybe silly. However from what I hear placing sleeve bearing fans vertically "can" lead to wear and tear which in turn can lead to added noise/grind.

My goal is silence (well as near as possible). I wouldn't want to have to replace my fans each year just because of wear and tear.

After doing a little more research my assumption is that fluid, rifle and magnetic bearings tend in "general" to be less likely to be noisy and have less tendency to wear and tear when placed in a non horizontal position.

NZXT (9 blade) have just brought some rifle mounted fans out so I may look at these, although from looking at the links the zalmans may be of use, especially on a fan controller.

ta