QUIETIEST 80mm fan with AT LEAST 50CFM?

003 · Post by **003** » Sat Jan 19, 2008 10:52 am

I like the S-Flex fans, I use 3 of the 49cfm version of them on my PA120.3. The only thing with the 1600rpm version is that it's only 63cfm, and I worry if that will be enough to compensate for the adapter and still maintain ~50CFM.

I also found a Yate Loon 70CFM 120mm fan rated at 33dB which looks pretty good, the D12SM-12.

I have read bad things about the higher speed papst fans so it's between the s-flex and the yate loon... which one should I use?

Shaman · Post by **Shaman** » Sat Jan 19, 2008 10:57 am

You should be looking at the SPCR own numbers in the fan round-ups. SPCR measured 70CFM for the S-Flex at 31dBA.

SPCR's Fan Testing Methodology is a good read.

003 · Post by **003** » Sat Jan 19, 2008 11:27 am

Well that settles that. I'm getting the S-Flex

dhanson865 · Post by **dhanson865** » Sat Jan 19, 2008 11:29 am

I think you are crazy for doing it but if you want a literal answer to the question of best 120mm fan near 70CFM I'd answer this:

SY1225SL12M (1,200 rpm version) 68CFM
http://www.scythe-usa.com/product/acc/0 ... etail.html

It should be about the best you'll do for noise to airflow ratio. If you put it on a fan controller it should be reasonable when you aren't running it full out.

The cheapest option I'd consider would be:
YATE LOON D12SM-12 (1650 RPM) 70CFM

The Slipstreams are about $8 and the Yate Loons are about $4 (both of those are before S&H). You are getting a better fan with the slipstream.

I personally don't see much reason to look past Yate Loon and Scythe. I tend to buy more on price than anything else but even then these are not low quality parts.

For example when you want a fan to run at 600-700 RPM you can just buy YATE LOON D12SL-12 (1350 RPM) 47CFM and put it on a lower voltage or speedfan and save the money vs a fan that costs several times as much.

If I had money to burn I'd instead go for the SY1225SL12L (800 rpm version) 40CFM and have a slightly slower fan that I'd have to run at a higher voltage to get to the same point. Either way I wouldn't be running it at 12v.

003 · Post by **003** » Sat Jan 19, 2008 12:03 pm

I had looked at the slip streams but I am partial to the S-flex fans. Would a slip stream push more air or be quieter than the s-flex? Maybe it would be a better idea because of the smaller diameter taken up by the motor compared to the s-flex, and more air would go through the adapter.

Now I'm stuck again. Which to get?

dhanson865 · Post by **dhanson865** » Sat Jan 19, 2008 12:23 pm

Well you know they are both made by the same company and That company claims lower noise on the slipstream. I'm usually hesitant to quote dba numbers from anywhere but SPCR but since we are comparing scythe to scythe...

SY1225SL12M (1,200 rpm version) 68CFM 24dBA
SFF21F (1,600rpm version) 64CFM 28dBA

Just realize quoted numbers for CFM and dBA are usually inaccurate.

Seems like I read a review on SPCR recently where they hinted that the slipstream was going to be the new choice for quiet (if only I could remember which one). Of course you are pushing the loud end of the slipstream family so it may be a tossup between it and the sflex.

003 · Post by **003** » Sat Jan 19, 2008 1:58 pm

I've ordered one of each. Now I'm going to leave this site and not look back. I don't want anymore confusion!

Post by **NeilBlanchard** » Sat Jan 19, 2008 6:44 pm

Hello,

The Slipstream is probably the quieter one, as it may blow more air at lower RPM's. It has 9 blades, and the struts are curved, which reduces turbulence aka noise.

Tell us how your new PSU works?

ryboto · Post by **ryboto** » Sat Jan 19, 2008 6:49 pm

I don't know what the CFM rating is, but I bought a 80mm Enermax Marathon because it was only $6 shipped, and because I'd had amazing results with the 120mm versions. All fans are incredibly quiet. The 80mm at 1500rpm adds zero noise to the system. It may even be quieter than the 900rpm 120's, or the same volume, regardless, I can't hear any of them from my desk chair.

Post by **NeilBlanchard** » Sat Jan 19, 2008 8:16 pm

Hello,

The one 80mm Enermax Enlobal Marathon I have is very quiet, but it vibrates pretty badly.

It is rated at 24 CFM, though.

To the original poster -- you may not really need 60CFM to keep the PSU cool.

ryboto · Post by **ryboto** » Sat Jan 19, 2008 9:04 pm

NeilBlanchard wrote:Hello,

The one 80mm Enermax Enlobal Marathon I have is very quiet, but it vibrates pretty badly. It is rated at 24 CFM, though.

I read a few newegg user reviews that claimed of vibrations, but I held the fan in my hand and turned it on and it was almost no different from holding it while it was off. Must be weak quality control.

Post by **MikeC** » Sat Jan 19, 2008 9:34 pm

If you're really committed to going the 120mm w/adapter route, then you could try one of the high pressure Scythe Ultra Kaze 120x37mm fans. The higher pressure will help push the air through the high impedance of the PSU interior. Otherwise, go for the Slipstream 120x25 1200rpm model.

003 · Post by **003** » Sat Jan 19, 2008 10:40 pm

Actually, the fan won't be blowing into the PSU, it will be sucking air out. And I already ordered a 1600rpm S-flex and the 1200rpm slipstream. I will see which works best. I like the S-flex because of the very long MTBF. But the new Minebea series has an even longer MTBF and a 75cfm/31dB model:
http://www.scythe-usa.com/product/acc/0 ... etail.html

How would it have done? Or is the slipstream and/or s-flex I got a better choice?

SebRad · Post by **SebRad** » Sun Jan 20, 2008 4:06 am

Hi 003, I think going down the route of 120mm fan on adapter out the back of the PSU is good. I've done a couple of PSU fan swaps (simple 80mm with slower 80mm) and in both cases I've connected the new fan to the PSU's fan header so the PSU retains control of the fan speed. That way it can slow the fan and be quieter when under less load and still ramp the fan up when more cooling is needed under load. I would suggest this to be a good idea with your fan swap if you possibly can. Also as the fan(s) you're swapping in have speed monitoring I would suggest monitoring the fan speed to see how close to maximum it's being pushed. If it's going to full speed you might need to think about a faster fan. To monitor the fan speed you can separate the 3rd wire from the 2 +/- power wires and route to motherboard fan header.
You can see how I did it here.
Good luck, Seb

Bluefront · Post by **Bluefront** » Sun Jan 20, 2008 5:04 am

My 2c........the 120/80 adapter idea is a poor work-around for a problem that may not even exist, on a PSU you haven't even tried out in your setup. The pieces are cheap, except the PSU I guess, so no big loss if it doesn't fit, or makes things worse.

Frankly trying to suck 70CFM through an 80mm hole, using a 120mm fan.....totally defeats the purpose of using a 120mm fan. It certainly won't be any quieter than running the thing stock, and might be much noisier, with little added cooling ability. There are plenty of other ways to keep a PSU cooler. How about a ducted intake from the outside directly to the PSU? Plenty of options exist......other than the one you seem to be stuck on. Good luck....you'll need it.

fri2219 · Post by **fri2219** » Sun Jan 20, 2008 9:14 pm

NeilBlanchard wrote:Hello,

There is absolutely NO WAY that any desktop computer can come close to requiring a 690watt PSU!!!

But wait, the reviewers at 3Dxxxxxxn said I need a 1Kilowatt supply!

Please don't tell me it's marketing hype, or some reviews are influenced by advertising revenues!

Post by **MikeC** » Sun Jan 20, 2008 11:16 pm

Bluefront wrote:My 2c........the 120/80 adapter idea is a poor work-around for a problem that may not even exist, on a PSU you haven't even tried out in your setup. The pieces are cheap, except the PSU I guess, so no big loss if it doesn't fit, or makes things worse.

Frankly trying to suck 70CFM through an 80mm hole, using a 120mm fan.....totally defeats the purpose of using a 120mm fan. It certainly won't be any quieter than running the thing stock, and might be much noisier, with little added cooling ability. There are plenty of other ways to keep a PSU cooler. How about a ducted intake from the outside directly to the PSU? Plenty of options exist......other than the one you seem to be stuck on. Good luck....you'll need it.

I tend to agree. But the OP has already admitted his standards for quiet are probably much different than most SPCR forum regulars... and the level of sophistication in design you suggest may be more than he wants to tackle.

003 · Post by **003** » Mon Jan 21, 2008 1:46 am

I'll bite. What is a ducted intake from the outside directly to the PSU, and how would I set one up?

Bluefront · Post by **Bluefront** » Mon Jan 21, 2008 2:26 am

There are examples of this posted here. MikeC wrote an article on maybe the easiest method. He used the top 5.25" bay. He constructed a mesh (I think) cover for the bay front opening. Then he built a duct (an air channel) from this front opening back to the PSU intake. He lined it with acoustic foam to keep the noise down.

These ducts can be made of anything stiff enough to hold their shape.....cardboard, thin aluminum sheets, plastic cut out of a "for sale" yard sign, etc. Cheap and easy way to feed a PSU cool air.

I wouldn't do that however. I'd build a short duct with a 90 degree bend, and cut a new intake on the right side of the case. Different method, same result, but quieter since the intake wouldn't be facing the front.

Post by **MikeC** » Mon Jan 21, 2008 8:04 am

003 wrote:I'll bite. What is a ducted intake from the outside directly to the PSU, and how would I set one up?

Ducted intake PSU in a Quiet PC for Torrid Thailand.

Shaman · Post by **Shaman** » Mon Jan 21, 2008 12:43 pm

However this duct solution assumes you give up the crazy 120mm-80mm adpater idea and use the stock 80mm PSU fan.

bonestonne · Post by **bonestonne** » Mon Jan 21, 2008 1:17 pm

the only time a PSU would ever need that kind of airflow is if its under a steady high load.

also, you mentioned power supply calculators, they're not completely accurate. some say my computer needs between 306 and 340W, but its only got a 300W power supply, and i've never had an issue with it.

and my PSU and exhaust fan are kicking out cool air, so i don't think you need 800+ at all.

003 · Post by **003** » Tue Jan 22, 2008 7:49 pm

MikeC wrote:and the level of sophistication in design you suggest may be more than he wants to tackle.

Yep you were right! Back to the mounting of a 120mm fan!