Panaflo: Noise of 92mm (low) vs. 80mm (low)

I want to get a Panaflo 92mm low for my heatsink and 80mm lows for 4 case fans. The 92mm is rated at 27db, and the 80mm at 21 db...so does this mean, effectively, that the 92mm will be heard above the noise of the 80mm's?

(...or is the 92mm actually quiter since it is larger....or...???)

I guess I'd like a comparison between the 2 types by someone who has them both. Or if you have a setup similar to the one I described, even better.

figure it will probly be about the same as another of the quieter rated 80's because the case its self will probly help to muffle the sound.... just a thought.

That's kind of what I was thinking, but I'm unsure since my case is all aluminum and doesn't really do much noise reducing (it's a Coolermaster Praetorian).

the larger fan may be noisier, but it may also be more tolerable at the same time. The larger fans seem to have more of a low pitched hum than a high pitched whine, even if actual dbas are different.

dB add together... Two of your 80mm together would work out to about 24dB; I am unclear how it behaves beyond that.

However I can tell you this. I have 4 80mm panaflos running in my coolermaster praetorian (2 bottom front, 1 below PSU, 1 HSF), and it is not terribly quiet for a computer in my bedroom - the plus is that you hear moving air, no whine or more annoying racket, just air movement. I changed out all the other fans first, and then I disconnected the blowhole fan because it was installed as an exhaust with a filter on it. I am not concerned about keeping dust from inside my computer out of my room. I was tired at that point and haven't gotten back to removing the filter and hooking up a panaflo there.

If you haven't purchased these fans already, you might want to look at bgmicro - they had the best price when I purchased 10 of them... http://www.bgmicro.com/prodinfo.asp...FAN1003&page=1&cri=FAN&stype=2&time_out=44:58

If you want to find out how loud your case fans are, just use:

dB = 10 log (x / 10^12) to find the sound intensity level (in W/m^2) of each fan, then add them together to find the total sound intensity, and plug back into the above equation for x to find the intensity level in dB.

The 21 dB fan has a sound energy output of 1.259e-10 W/m^2 and the 27 dB fan has 5.012e-10 W/m^2. Since you have (3) 21 dB fans, and (1) 27 dB fan, you add these sound energy output together. Plugging them back into the above equation, I got a grand total of 29.44 dB.

Okay, good responses.

I'm thinking that with my particular case, no matter what I do the heatsink fan will be a pretty big factor leaking noise. The case itself is great in terms of looks and excellent with cooling, but I've come to realize that it stinks with noise leakage.

So I think I should perhaps try experimenting with running all of the said panaflos fans at 7volt just to get the noise down a bit more. (To refresh my memory, 7volts is the min voltage for panaflos, right? ....or was it 5?)

It's 5. I've got a 92mm L1 and an 80mm and the 80mm is much quieter at 5v, 7v, and 12v, but that may be due to the fact that my 80mm is made in Japan and my 92mm is made in China. Panaflo's that are made in Japan are quieter than Panaflo's made in China.

5v is good...nice room to work with.

maybe, i need to go a different route with my heatsink fan though...like a variable speed fan that automatically adjusts...

Personally, I've never been a big fan of temperature controlled fans. I've found that they never really get up to a decent speed (unless your motherboard is on fire). I think I saw a test somewhere that the only time a thermistor-controlled fan got up to full speed was when the temperature was 65C. Not likely.

What I usually do is buy the high CFM Panaflo's and hook them up to a Sunbeam fan controller. This way, I control how fast they are going. If I'm only browsing the web, I turn them down for peace and quiet, and when I am doing something CPU-intensive I turn them up.