whats most quiet/effective

What would be the most silent and/or efficent:

A. A slow fan at full speed

B. A fast fan at low speed

?

Or can you not make such generalizations

If they're the same size, I don't know if it makes a difference. A slow fan, at say 2000 rpm at full speed will produce a certain amount of noise, right? A fast fan at low speed will be turning at the same rpm, or something close to it, should be similar Dba produced. The only variable I can think of would be the bearings on the fan...if the slower fan has different bearings, at full speed could be a bit louder, but not noticeably.

Generally they are the same.

ie- Take an 80mm panaflo high and low. The high at 7v is about 2k rpm's, While the low at 12v is about 1.9k rpm's. So they are basically the same then. The only difference being if you have a low you can taken slower/quieter than the high could ever be with undervolting.

If your looking for a quiet fan, I'd pick up some low-speed ones. That way if they aren't quiet enough, you can undervolt them. If you pick up some high-speed fans and run them at 5v/7v, that's around the lowest they can go. Which leaves you no headroom for noise.

Im running 2 x 120 mm 55 cfm case fans now, they dont push much air honestly. Its only a slow breeze Cant imagine what use even slower fans would be.

id recccomend some moderately noisy fans (around 30-35dba) and use a fan controller, it really does work best, well for me anyway.
im running a 70mm evercool, and with it running at just 80% its inaudible!

some high speed fans will have more motor noise audible when running on lower voltage than a low speed/low noise version.

slow fan will move more air while being quieter then a modded fast fan

If you want the quietest setup get 120mm x 38mm case fans that push about 85 cfm at 12 volts @ around 35 db. Then get a fan controller turn them all the way up for great cooling and down to the low setting for ultra quiet operation.

Hmm seem to be a pretty narrow choice at those specs. In my country I can only find the Papst 4412FGM: 120x25mm, 2400rpm, Sleeve Bearing, 82.4 cfm, 38 dB. Priced about as the same as any other 120mm around. Papst is the most common brand here as it seems.

Other than that, I can only find Sunon and Deltas overseas and its too much of a hassle to import for just 3 fans
Doesnt sleeve bearing sound a lil weak for a 82 cfim fan??

Which country do you live in?

Papst are good and usually have little motor noise.

Shadowknight281 said:

Which country do you live in?

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Im in Sweden...very small, cold and boring communist country in northest part of Europe. Located at about the same latitude as Anchorage, Alaska.

Hmm teh higher sound of slowed down high speed must be due to the ball bearings? Papst makes 100 cfm sleeve bearing fans

Any word on fan controllers?

Tomatosaurus[RE said:

Any word on fan controllers?

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One word, "Sunbeam", 1.6a per channel. One of the best on the market. Sturdy, well made and looks fantastic. Also allows one to change the LED's if one would want to.

I got an Aspire 120x25mm exhuast fan pushing about 89CFM at max speed, even at 12v it is still very quiet, but running it about 5 ~ 7v keeps it almost dead silent, at the same time as moving alot of air.

Son1990 said:

One word, "Sunbeam", 1.6a per channel. One of the best on the market. Sturdy, well made and looks fantastic. Also allows one to change the LED's if one would want to.

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Rheobus 20w x 4 rev 3 ?

Tomatosaurus[RE said:

Rheobus 20w x 4 rev 3 ?

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Not a bad choice.

K Ill try the Rheobus + 2 x 120mm Papst 82 cfm + 1 x 80mm Papst 47 cfm. Maybe it will do the trick for both good & silent cooling.

Thx for advice.

Awright, I got the setup now. I bought the 3.5" black version of the Rheobus, it handles 10 watts per channel instead of 20 as the 5.25" version, but it has no ugly text printed on it and 10 watts is plenty more than I need anyway so.

I can highly recommend this product!! It will look great in any black case, propably especially in a lian-li cause it has the exact same surface. Also construction quality is great. Comes with 2 fan cable extenders aswell. Very stylish and with cool blue LED:s to light up the dark! Cost me 18 euro including shipping.

As for the fans I can say that the 82 cfm 38 dB fan will run even quieter than than the 55 cfm 26 dB does at full speed. I tried to compare their soundlevel at the same cfm and they seem to have the exact same sound level.

Big for this product aswell. Product name is Papst 4412 FGM. Specs 82 cfm 38 dB 270 mA 7-12.6 V 3.2w@12v. Its pretty silent even at full speed, I guess this is because it doesnt have a ball bearing like most other 80+ cfm fans. At 7 volts its very silent.

Im not sure the 80mm fan is OK, I never had such a powerful 80mm before, but it sounds like the motor makes more noise in it than in the 120mm fan, even tho its 2.8w instead of 3.2w. Even at the lowest setting on the rheobus its abit louder than the other 2 80mm fans I have at hand - a papst at 19db and an adda wich is even more silent. But it also moves more air.

More testing is upcoming.