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FOP's and 80mm fans, which fan is best?

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AKDUDE

Senior Member
Joined
Feb 13, 2001
Subject line says it all. Basically im looking for the most CFMs at the same sound level as my FOP 32 is at.
Weres a good site that I can buy a fan from, that shows CFMs, and DBa?
Thanks!
AKDUDE
 

Nagorak

Senior Member
Joined
Dec 19, 2000
Fan listings

Here are some links to fans found at 2CoolTek and Pham Computer. Basically all but the Adda fans are listed at 2CoolTek, the Adda fans being at Pham. You can click on the links below to go straight to the fan information page at each of the sites.

Panaflo 80mm- 24.0cfm at 21.0 decibels

Panaflo HO 80mm- 39.6 cfm at 32 decibels

Sunon Quiet 80mm- 30cfm at 28 decibels

Sunon 80mm- 36cfm at 32 decibels

Sunon HO 80mm- 42.5cfm at 36.5 decibels

Adda Quiet 80mm- 26.2cfm at 22.5 decibels

Adda HO 80mm- 50.0cfm at 40.6 decibels

As far as I can tell the YS Tech 60mm fan (on the FOP 32) is 26 cfm at 36 decibels. So you could go with either the Sunon HO (High Output) 80mm fan or the Panaflo HO 80mm fan without increasing your noise level(the Panaflo would actually decrease it). For some increase in noise, you could go with the Adda HO fan. I have the Panaflo HO myself and I can personally vouch for the fact that it is MUCH quieter than the YS Tech.

One thing to keep in mind is decibels scale exponentially. Thus an increase of 3 decibels actually results in double the sound volume. This is just about right in line with my experiences because the YS Tech is at least twice as loud as the Panaflo 80mm HO fan, and it also has an annoying high pitched whine (of course you have the fan so you know).

I have also discovered that it is possible to attach a 92 mm to the top of the WBK/FOP using a metal fan guard. Attach the fan guard to the bottom of the fan (the part facing down towards the heatsink) and then attach the heatsink's fan clips to the grill. This would allow you to use even larger 92 mm fans with the FOP and get even more cfm for fewer decibels.

The only problem is the 92mm overhangs the heatsink quite a bit. To counter this, I created a shroud out of duct tape, to make sure the air is flowing over the heatsink. I suppose you could also do this with a 120mm fan, but I think that would be mostly pointless since a 120mm is so much larger than the heatsink.
 
OP
AKDUDE

AKDUDE

Senior Member
Joined
Feb 13, 2001
Thanks for the great post Nagorak!
I certainly do not want to get any louder, so Ill follow your tips. I tried mounting a ANTEC 92mm case fan on it, but the temp just went up 3 degrees and was still climbing when I shut down to switch back. I got the ANTEC at a Comp USA during a spell of idiocy. It doesn't actually move that much air at all, but it sure is quiet. I was able to mount it without a guard with zip ties.
I guess your right on the 120mm, you could use one, but ducting it would be no fun. If I did something like that, I would mount it to side panel of the case, and duct it into the heatsink, with no risk of the extra weight and stuff damaging the cpu.

Another problem I have is that since the heatsink fins are up and down, it blows hot air on the back of the video card. I notice that if I put a fan at that location, pointing outward from the case, the temp drops down 1c.

Anyway, thanks again for advice!
AKDUDE
 

Hoot

Inactive Moderator
Joined
Feb 13, 2001
Location
Twin Cities
Try to remember that CFM ratings are based upon the fan hanging in the air, with no resistance to airflow. With most fans, the CFM plummets in the presence of back (static) pressure. That is the resistance to airflow one might encounter blowing down into a heatsink, or trying to suck air into you case through an escutcheon with tiny holes or slits.
Generally, the thicker the fan, the better it's performance in the presence of back (static) pressure.

Note: Spraying your fan blades with Clingfree will not reduce static pressure :)

Hoot
 

Nagorak

Senior Member
Joined
Dec 19, 2000
If you decide to go with a 92mm, the Sunon 92mm (44 cfm, 33 dBA) is pretty good. Not quite as quiet as the Adda Quiet (41.6 cfm, 29.8 dBA) or Panaflo 92mm (42.7 cfm, 270. dBA), but it is still pretty quiet and moves a little bit more air. There's also the Sanyo Denki 92mm which moves 55cfm, but it's getting up into the disagreeable (to me anyway) 36 decibel range.

I'm actually quite impressed by the Panaflo fans in general. I've considered swapping out all my fans for Panaflo fans in an effort to decrease noise. The only thing is, I don't know what I would do with all of the fans I have left over then. Unlike processors/video cards, selling fans on Ebay is a pain...
 
OP
AKDUDE

AKDUDE

Senior Member
Joined
Feb 13, 2001
Well, I started digging around, and I found a sunon 36cfm fan that is 80mm.
Mounted it up, and pretty much got the same temp rating. BUT it is ALOT quieter than the 30. Now I can't hear my computer from across the house, and thats a good thing. I could stand some more noise for lower temps though.
I have a EPOX 8kta3 and the capacitors and mosfets next to the cpu get really hot. So I offset the mounting of the fan to blow on them as well.
Thanks for all the input guys, now im starting to think about duckting a 120mm into the cpu... now how cool would that be eh?
:D :D :D
AKDUDE
 

Hoot

Inactive Moderator
Joined
Feb 13, 2001
Location
Twin Cities
A caveat when mounting increasingly bigger fans on a blow-down type HSF.

Make sure not too much air blows down the outside of the perimeter of the HS. The idea behind blow-down HSFs is air travels down the fins hits the baseplate deflects and exhausts out of the HSF. If too much air is blowing down alongside the perimeter of the HSF, when it hits the motherboard surface and deflects, it may impede the air trying to exit at the baseplate.

Yet, again, my $.02 worth...

Hoot
 
OP
AKDUDE

AKDUDE

Senior Member
Joined
Feb 13, 2001
Good point, makes even a better case for ducting the fan.
Sometime awhile back I heard about someone selling a sheet metal cowl, or duct or whatever you want to call it, that would duct a 80mm fan down to a regular sized heatsink. May be worth looking into or copying.
I havn't bent sheet metal since highschool :D
AKDUDE
 
OP
AKDUDE

AKDUDE

Senior Member
Joined
Feb 13, 2001
Heres a pic of it.
[img="[URL]http://albums.photopoint.com/j/View?u=895064&a=6514152&p=43937579&Sequence=0&res=high[/URL]"]
[img="[URL]http://albums.photopoint.com/j/View?u=895064&a=6514152&p=43938642&Sequence=0&res=high[/URL]"]

Heres a pic of it.
AKDUDE
 

Nagorak

Senior Member
Joined
Dec 19, 2000
Hoot (Mar 16, 2001 10:38 p.m.):
A caveat when mounting increasingly bigger fans on a blow-down type HSF.

Make sure not too much air blows down the outside of the perimeter of the HS. The idea behind blow-down HSFs is air travels down the fins hits the baseplate deflects and exhausts out of the HSF. If too much air is blowing down alongside the perimeter of the HSF, when it hits the motherboard surface and deflects, it may impede the air trying to exit at the baseplate.

Yet, again, my $.02 worth...

Hoot

Yea, I am kind of concerned about this myself, to be honest. Not sure exactly what can be done about it though :-/
 

Nagorak

Senior Member
Joined
Dec 19, 2000
Here's an update on my experiences with the FOP + hack. I was running it with a 92mm for a while and now I have gone back to an 80mm instead. It seems that my temps are slightly lower with the 80 (or about the same) with the 80 even though it is blowing slightly less air. This leads me to believe that the 92mm is just not working as efficiently because it is too large for the heatsink. Seems like the best bet is probably to go with the 80mm and not the 92.