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View Full Version : Fan CFM, finding that optimal number.


sunrunner20
10-18-04, 05:38 PM
Im wondering what fan CFM I should have for the two 120mm fans I will be attaching to a 2-302 Heater core, I am currently looking at two $20 ea 114CFM Panaflo fans. The reason I ask is, I know that more CFM = more noise, and I am wondering if a total of 228 CFM(peak) would be over kill. I also plan on useing a fan controller, becuase I know that will help with the noise level, but $20 a fan if you won't need it is kind of a waste.

PS: the watercooling loop will have a P4, my NB, and my 6800U(once i get the $$) on it.

Achilles17
10-18-04, 06:10 PM
find out the dba of the fan, thats how loud it is. The best your going to find are the $5 sanyo denki fans in the classifides, 105 cfm 39 dba. Plus they are just damn cheap on ebay (search for sanyo denki, buy it now for 4.99). $20 each for fans is rediculous.

Alacritan
10-18-04, 06:20 PM
Get 120mm Sanyo Denki's (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3673&item=6715723763&rd=1). They're 102cfm, which is plenty, but they have a higher static pressure than the Panaflo's, which is important when using a heatercore. The dense fins of a heatercore combined with it's depth prevents low static pressure fans from effectively penetrating all the way through. 100cfm fans are plenty. You won't notice much difference in temps above half speed unless your rig runs really hot.

[KX3]rAge
10-18-04, 06:22 PM
Get 120mm Sanyo Denki's (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=3673&item=6715723763&rd=1). They're 102cfm, which is plenty, but they have a higher static pressure than the Panaflo's, which is important when using a heatercore. The dense fins of a heatercore combined with it's depth prevents low static pressure fans from effectively penetrating all the way through. 100cfm fans are plenty. You won't notice much difference in temps above half speed unless your rig runs really hot.
Just out of interest does anyone have a guess on the specs of the Sanyo's at 7v??

Alacritan
10-18-04, 06:27 PM
I really couldn't say. I run mine at 5V and temps only increase by 1-2C at most compared to 7V. If I had to guess I'd say maybe 70-80cfm at 33dba. But that is one hell of a guess. I really have no idea. Suffice to say they're nearly dead silent at 5V and the only reason they're louder at 7V is that they're pushing more air. There is no motor noise I can hear.

[KX3]rAge
10-18-04, 06:48 PM
I really couldn't say. I run mine at 5V and temps only increase by 1-2C at most compared to 7V. If I had to guess I'd say maybe 70-80cfm at 33dba. But that is one hell of a guess. I really have no idea. Suffice to say they're nearly dead silent at 5V and the only reason they're louder at 7V is that they're pushing more air. There is no motor noise I can hear.
Awesome, thanks :)

sunrunner20
10-18-04, 07:09 PM
Achilles17: I do belive that i am unable to get to the classifides becuase im under ~60 posts :-\ I don't like this ranking system

sunrunner20
10-18-04, 07:17 PM
spec sheet?
Edit: nevermind I found it

Modle number? the one on the ebay is not valid.

ls7corvete
10-18-04, 07:47 PM
The ones in the classifieds are the same as some of the ones on ebay.

Try silentPCreview.com for specs of fans at 5v and 7v. It may or may not have the sanyos.

http://silentpcreview.com/article25-page1.html

Alacritan
10-18-04, 08:05 PM
The ones I linked are the same ones as in the Classifieds, same seller too. $5 a piece.

sunrunner20
10-18-04, 08:10 PM
well, the panaflo(the $20 one) has 114 CFM at 78 Pa at 45.5 dB-a , It would also be nice to know a retailer for all of the Sanyo Denki fans.

Alacritan
10-18-04, 08:11 PM
This is the closest I could find to the ones on Ebay.

http://sanyodb.colle.co.jp/product_db_e/coolingfan/dcfan/dc_fan_detail.php?master_id=1140

Also where did you get those numbers for the Panaflo H1A? I've seen completely different numbers than those. I saw the 120mm H1A rated at 103cfm, 42dba and 66 Pa, but when I compared it to my Sanyo's I can honestly tell you they're a bit optimistic. It certainly wasn't 114cfm and 70+ Pa coming out of the Panaflo, but 40+ dba might be accurate. Louder than my Sanyo's at least.

Jbroad572
10-18-04, 08:44 PM
Guess these fans I bought are not going to cut it, lol. I knew it was too good to be true, they are just too quiet. Maybe they will make good case fans....
http://svc.com/tlf-s12-ew-19.html those are the ones I bought hoping they would work nicely.
They are only 42cfm though.

sunrunner20
10-18-04, 08:46 PM
FBA12G12U1A
http://www.panasonic.com/industrial/appliance/pdf/fba12g.pdf :santa2:

Alacritan
10-18-04, 09:04 PM
That's the U1A, not the H1A. The U1A is difficult to find, not much better and WAY the hell louder.

But I suppose if you don't mind the incredible noise, they are technically better than the Sanyo's (though not from a noise to performance or even price to performance ratio). The Sanyo's are also much better built fans than the Panaflo's in my opinion.

sunrunner20
10-19-04, 05:40 AM
least I can find an offical resaler for the panaflo's....

care to link me to one?

Alacritan
10-19-04, 08:04 PM
Official resaler? Why bother? That just means you'll pay retail price for it. They guy who sells 'em on ebay is a fan wholesaler who also lists stuff on ebay. Plenty of computer sites do that with hardware.

Everyone on OCForums who uses Sanyo Denki's has bought them from this seller.

sunrunner20
10-19-04, 08:24 PM
I normally try to avoid places like ebay.

JeffP
10-19-04, 08:29 PM
least I can find an offical resaler for the panaflo's....

care to link me to one?

Ummm here. http://www.directron.com/fba12g12h1a.html

Achilles17
10-19-04, 08:33 PM
I normally try to avoid places like ebay.

But when you know this guy is good, and considering around 50% of the people on the WC forum have the Sanyo Denki fans, and bought them from THAT seller (I just got mine a few days ago, theyre great), theres no reason to be scared. Plus, they are way better than the panaflo's for much less.

sunrunner20
10-19-04, 08:47 PM
from the spec's I saw, they aren't as good as panaflo's. And 1. not the panaflo im looking at, and I im refering to the Sanyo Denki distrib.

Alacritan
10-19-04, 10:01 PM
And I'm telling you, as I've owned both fans, the Sanyo's are decidedly better. They're quieter, push more air and are much better built. The Panaflo stats are overrated. It does not push more air than the Sanyo. I used to use Panaflo's but side by side comparison has proven that Sanyo's are the better fan.

But hey, if you seriously want to spend three times as much for a fan because you're paranoid, it's not my money. I'm just giving you advice. It's up to you to ignore or disregard it.