Need QUIETEST 80mm fan that pushes the MOST air!!

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003
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Need QUIETEST 80mm fan that pushes the MOST air!!

Post by 003 » Sun May 13, 2007 10:20 am

Ok so basically I need a new fan for my power supply. I made this thread at another forum, so I will link to it instead of typing it again:
http://www.head-fi.org/forums/showthread.php?t=240376

Also, if anybody is interested in knowing what the other fans in my case are, it would be:

(3) Scythe S-FLEX SFF21D

(1) Coolink SWiF 1202

(1) AeroCool Aerolite BB

(1) Zalman VF700-Cu video card cooler, fan set to the quiet setting

Unless anybody happens to know any of these fans are noisy and/or problematic, I am pretty sure the AeroCool is the only one making a lot of noise.

Please, anybody help me. I need to silence the PSU. I read something on XtremeSystems about somebody finding a 80mm to 120mm fan adapter and using it to have a 120mm fan sticking out of the back of the turbo cool 510 psu. I would love to do something like that because there are plenty of 120mm fans that push enough air and are quiet enough but I can't find any kind of "80mm to 120mm" adapter.

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Post by Bluefront » Sun May 13, 2007 10:59 am

Hummm.....don't we all. Here's the quietest 80mm fan I ever heard, that pushes a decent amount of air. The thing here is......."quietest" and "pushes the most air" don't go together. You get one or the other....never both, despite the claims of the SilenX-type companies. Normally sleeve bearing fans are quieter than ball-bearing fans. And a Yate Loon is a good brand. These fans are really quiet.....whether they push enough air for your project is another matter.
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003
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Post by 003 » Sun May 13, 2007 11:03 am

What about using an 80mm to 120mm adapter? I finally found something:
http://www.svc.com/fa80120-uvblu.html

Will that allow me to have a 120mm fan sticking out the back of the PSU?


Also, I am in need of the quietest possible 80x80x15mm fan there is. I run a small server, and it's PSU uses one of these fans. It's not the noisiest thing ever but it's not the quietest, either. I'd like to replace it with a quieter one if possible.

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Post by Bluefront » Sun May 13, 2007 11:25 am

IMHO...don't waste your time with that sort of adapter. They don't work very well. Here's the quietest 80x15mm fan. Also the most expensive. But there is no comparison between this fan and the other thin fans. It's worth the extra cash......
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Post by YugenM » Sun May 13, 2007 12:00 pm

Pair of Panaflo L1's at 10.5V-ish in my Powerstream 520 have been performing well for the last couple of months; PC draws about 240W.

003
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Post by 003 » Sun May 13, 2007 12:13 pm

Thanks. Quick question. To determine the noise level of a PC, lets say you have two fans in it that are both rated at 20dBA (lets assume that is accurate). Would the total noise level be 20dBA or 40dBA?

Also, while searching for quiet fans, I see some with the airflow measured in m³/h instead of cfm. How do you convert that to cfm?

And lastly, if I put two 20cfm fans on top of each other, each blowing the same direction, would that then turn into 40cfm?

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Post by qviri » Sun May 13, 2007 12:31 pm

003 wrote:Also, while searching for quiet fans, I see some with the airflow measured in m³/h instead of cfm. How do you convert that to cfm?
Google is of help.
And lastly, if I put two 20cfm fans on top of each other, each blowing the same direction, would that then turn into 40cfm?
No, it would turn into 20 cfm with a greater ability to combat obstructions (fan grills, etc). To turn it into 40 cfm you'd need to place them side by side.
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Post by jaganath » Sun May 13, 2007 12:39 pm

both rated at 20dBA (lets assume that is accurate). Would the total noise level be 20dBA or 40dBA?
neither, it would be 23dBA. check out this stickied thread.

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Post by Sylph-DS » Mon May 14, 2007 3:18 am

jaganath wrote:
both rated at 20dBA (lets assume that is accurate). Would the total noise level be 20dBA or 40dBA?
neither, it would be 23dBA. check out this stickied thread.
Not quite, two times 20dB would turn into 23dB, but dBA isn't dB. Besides that, this rule only counts when the two sources of sound do not effect eachother, in fans, they most likely do.
Try this little article.

Edit: Ok, that was careless of me. The article I have here is the same as was posted before. My apologies. The other comments in this post still stand though..
Last edited by Sylph-DS on Mon May 14, 2007 5:30 am, edited 2 times in total.
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Post by jaganath » Mon May 14, 2007 3:29 am

you linked to exactly the same thread I did. my god this forum is full of nitpickers.

003
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Post by 003 » Mon May 14, 2007 4:24 am

Ok, now I am getting somewhere. My system used to have the following fans:

(3) Scythe S-FLEX SFF21D (8.7dBA each)

(1) Coolink SWiF 1202 (24 max dBA)

(1) AeroCool Aerolite BB (rated at 26dBA, but sounds louder)

(1) Zalman VF700-Cu video card cooler, fan set to the quiet setting (20.35 max dBA)

It will now have the following fans:

(3) Scythe S-FLEX SFF21D (8.7dBA each)

(1) Zalman VF700-Cu video card cooler, fan set to the quiet setting (20.35 max dBA)

(2) Scythe S-FLEX SFF21E (20.1dBA each)

Is that pretty good? Is there any way I can calculate the total noise from all these fans? I know you don't just add up each dB rating, and I also know that having two or more fans of equal dbA will be more than the original noise level. Its something like +3dBA for each identical noise source, but what about non-identical noise sources?

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Post by thejamppa » Mon May 14, 2007 4:38 am

it seems you have taken some fan's specs quite literally. I think S-FLEX SFF21E noise levels are closer to 25 dBA in real life. Considering with that many fans, your noise around 32 to 35 dBA, estimating all your fans ( except Zalman ) are at full speed.
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Post by NeilBlanchard » Mon May 14, 2007 4:50 am

Hello,

The noise ratings on most fans are crap, frankly. There is NO WAY that the Scythe fans are 8.7dBA, for example. At least, not if you measure it with a standard method. I would be very surprised if they are 18.7dBA at one meter.

So, no you cannot just "add up" the noise ratings to find out how loud your system is. Going by the RPM's of each fan is a better way to gage noise.

You'll have to make the judgment for yourself -- can you hear it during the daytime? Can you hear it when it at night (or whenever it is quietest) in your room? What is the loudest component in your system?

Six fans in a system is a lot. Are you counting the PSU fan, and/or the northbridge? I have three in mine -- including the PSU fan, and the case exhaust fan only runs part of the time:

1)SeaSonic S12 430 (Adda 120mm ball bearing) averages 700-800RPM.

2)Scythe DF 120mm case, it runs when the CPU above 52C and averages 800-900RPM when it is running at all.

3)Scythe DF 92mm medium speed at 5volts, and runs about 1300RPM IIRC This fan is only required because I have a Seagate HD that gets fairly warm.

I have an Athlon 64 X2 4200+ with a Scythe Ninja (original version) with no fan, on a Gigabyte SLi Pro mobo with passive cooling, and I have two 7600GS video cards with stock passive cooling. All installed in an Evercase 4252: viewtopic.php?p=319124&highlight=#319124
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003
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Post by 003 » Mon May 14, 2007 1:08 pm

Awwww crap... so the S-flex fans are not the quietest 120mm? Ok, then I have two questions. First, what is the QUIETEST 120mm fan PERIOD, and second, what is the quietest 120mm fan that pushes a halfway decent amount of air?

And for reference, what is the quietest 80mm fan PERIOD, and what is the quietest 80mm fan that pushes a halfway decent amount of air?

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Post by Bluefront » Mon May 14, 2007 3:04 pm

Heh....Again. It's pretty easy to pick out the quietest fans. According to the latest SPCR testing, most 120mm fans push about the same amount of air at a given rpm. And since it's the amount of airflow that determines the noise for the most part, the quietest 120mm fan is the one that will run the slowest RPM. If you don't control the fan voltage, the Nexus is probably one of the quietest at 12V, since it only turns 1000rpm@12v. I think there are several that turn about 800rpms at 12V. They may be quieter than the Nexus.
Last edited by Bluefront on Mon May 14, 2007 4:36 pm, edited 2 times in total.
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003
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Post by 003 » Mon May 14, 2007 3:14 pm

Ok, I just ordered two of the Nexus fans which I will use on my CPU and PSU. The other S-flex fans I will keep, the ones rated at 8.7dba, which is probably not true, but I am going to guess, they ARE quieter than the nexus, and they are indeed 800rpm.

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Post by NeilBlanchard » Mon May 14, 2007 3:51 pm

Hello,

How do the 800RPM S-Flex sound -- are they smooth with the "whoosh" dominant, or do you hear some bearing noise and/or a growl and/or any ticking? What are the qualities of the sound they make?

Are you using 80mm fans, or 120mm? What is the case, and have you considered improving the air flow, so you can use fewer fans?
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003
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Post by 003 » Mon May 14, 2007 4:39 pm

The 800rpm S-flex fans are inaudible over the AeroCool and Coolink. All 120mm except the AeroCool which is going to be replaced with a 120mm using an 80 to 120mm adapter.

The case is an NZXT Lexa. I can't remove any fans, I am skimping as it is. The PC is:

Opteron 165 overclocked to 2.8GHz, with a Noctua NH-U 12 heatsink, DFI LanParty nF4 Ultra D mobo, evga geforce 7800GTCO, 2x1GB RAM, etc...

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