Are there any quiet 120mm x 38mm fans?

ferdb · Post by **ferdb** » Wed Oct 13, 2004 10:15 am

I've been looking for 120mm x 38mm fan that's quiet when undervolted for a water cooled system. I have had no luck in finding a decent quiet fan of that size. I tried Panaflo FBA12G12L1A's, Papst 4212L and Sunon KED1212PMB3-6A. They all have a lot of motor and friction noise, the Papst is probably the worst. The Globe and Nexus 120mm fans I have are good, but only 25mm thick and weak on airflow in a restrictive system. Do I just have bad examples of the papst and Panaflo? or has the quality just gone to pot and they don't make any good ones anymore?

ferdb · Post by **ferdb** » Wed Oct 13, 2004 5:56 pm

Well I've started to dissect some fans to see if I can't modify the electronics to smooth out the switching pulses which seem to cause the 'diesel engine idling' noise out of these panaflo, papst and sunon fans. Maybe I can come up with something, I don't think I'm going to find an off the shelf 120x38 fan that's reasonably quiet.

Becks · Post by **Becks** » Wed Oct 13, 2004 6:16 pm

I doubt there is a very quiet 120x38mm fan, I've read before the 120mm panaflo wasn't very quiet... had thought it had to do with the hydrowave bearing, but I would have thought the 38mm thick papst would be similar to the 25mm ones- guess not :/

You could always switch to a transmission cooler ;P

pony-tail · Post by **pony-tail** » Wed Oct 13, 2004 9:26 pm

I have 4 x panaflo 120 x38 L fans - 1 is badly noisy (growls at all speeds)
1 clicks and two are very good (all Japanese) all bought from the same place but over a 6 month period .
I also have an EBM 120 x 38 low speed fan (in use at the moment ) Dead Quiet - but very little airflow . I do not know a lot about the EBM except , it has sleeve bearing and spins very slowly ( it came out of a Digital branded PSU that was made in Germany ) and is now 5 years old and still very Quiet .
But also probably not what you are looking for due to the low airflow.
I have 2 Nidec 120 x 38 fans (low speed) 3 blade ones 1200 rpm (they have speed monitoring) low airflow AND noisy (motor switching noise)

I also have a Maxima CH12S12M which is 120X30 and is Quiet at 6volts but do not know where it came from originally as it was purchased for $2 at the local Computer Market (kind of ,like a Swap meet)
But no matter what brand fan you get in the 120mm x 38mm out of each batch there seems to be a couple of very good ones and the rest scale from good to bad .
I suppose if you buy a Fonsan or a Delta you get 100% as you know they are all going to be loud .

But even that is in doubt as Delta is doing research to try to make quieter high performance fans - I hope they succeed too as their fans last for years .
I could be wrong here , but if big companies like Delta are starting to see a market for Quieter components , then maybe a market shift is happening
While we watch .

ferdb · Post by **ferdb** » Thu Oct 14, 2004 4:25 pm

Of the Sunon, Papst, and Panaflo the Sunon has the lowest motor impulse noise, probably because it's a 6 pole motor instead of 4. The Papst has the most bearing noise, followed closely by the Sunon, scrape...scrape. The Panaflo is by far the quietest on bearing noise, soon as you remove power from and let it spin down it gets pretty quiet, applying power though and the diesel engine starts chugging away. I've been carefully tearing open one of each of these fans. You must remove the blade assembly to get to the Papst circuit board so fiddling around with it is a pain since you need to reassemble the fan every time you want to run it. The Sunon and Papst fan assemblies are easy to take off, you just remove a circlip. The panaflo looks like it has a swaged metal cap on the end of the shaft which I couldn't get off so I cut into the back of the fan to expose the PCB. I'm tinkering with the Panaflo atm since it has the lowest bearing noise and the best possibilities. The Sunon also may have possibilities but it has a lot of bearing noise. I tried packing the bearings with grease to reduce the bearing noise on the fans but with little effect. This may all lead to nothing and I'll be stuck with using 120x25 fans or stacking them or going with 120vAC fans and just vary the voltage on them to speed control them.

The fact that you got a couple good ones Pony-tail inspires me to order some more panaflos and hope I find some good ones.
EBM and papst merged I believe, maybe the only good EBM/Papst fans are the old ones.

thanks all for the feedback

Interitus · Post by **Interitus** » Fri Oct 15, 2004 11:52 am

Have you tried the OEM "Blue Label" Panaflos that Ralf used in his BQE?

They're very nice and don't click/buzz/whine when undervolted. Of course they can't be run quietly at 12v though.

Straker · Post by **Straker** » Fri Oct 15, 2004 3:48 pm

i was going to suggest simply stacking them too - even better if you can find two brands/models that rotate in opposite directions of course.
if it's a radbox or if space permits, push/pull may be worth trying too, if you're using a rad more than an inch thick.

DrCR · Post by **DrCR** » Fri Oct 15, 2004 9:02 pm

Hey ferdb, glad you made you way over here.

Posting in that thread at PC got me thinking. I started a topic in the watercooling forum here at SPCR you might be interested in (link).

On the side: There's always the Sunon MagLev 120mm 'squirrl cage' blower to look into. Never did find out just how quiet they are though. Do a search on my past postings, the thread titles should be obvious.

Feel free to send me PMs, and let me know if you ever find a 25mm+ thick quiet axial!

Cya Around,

DrCR

_________

ferdb · Post by **ferdb** » Sat Oct 16, 2004 12:00 pm

Interitus wrote:Have you tried the OEM "Blue Label" Panaflos that Ralf used in his BQE?

They're very nice and don't click/buzz/whine when undervolted. Of course they can't be run quietly at 12v though.

Where do you get the Blue label Panaflos? I'm willing to try anything.

After dissecting several 120x38mm fans I've found the source of the diesel engine idling noise. It comes from the rapid switching of the coils in the motor and the interaction with the strong permament magnets in the rotor. The large diameter motor hub in the 120x38mm fans also means there is a lot more torque generated when the coils are switched, generating a large rotational torque pulse that shakes the fan and causes the noise. I modified the coil drive circuits to smooth out the coil switching and it does reduce the 'engine' noise quite a bit at low rpm, at higher rpms though it cuts down on max rpm, overheats the coil drive transistors, and can cause some extra shake. So it runs much smoother and quiter at low rpm, but rougher when it gets up near full speed. Not perfect maybe but an interesting first try. Removing the spider and shroud and just running the central fan cuts down on the noise also, so it might be possible to add some damping to the back of the fan and the spider to reduce the noise. It might be necessarry to actually cut the spider loose and then remount it to the shroud with some damping material.
What I really wish is that Globe or Nexus would just make a 120x38 fan with the same drive motor as the 120x25s they make.

Fat Bunny · Post by **Fat Bunny** » Sat Oct 16, 2004 12:06 pm

ferdb wrote:Where do you get the Blue label Panaflos? I'm willing to try anything.

Only place I have seen is ThermalFX.

pony-tail · Post by **pony-tail** » Sat Oct 30, 2004 7:04 pm

I suppose if you buy a Fonsan or a Delta you get 100% as you know they are all going to be loud .Twisted Evil
But even that is in doubt as Delta is doing research to try to make quieter high performance fans - I hope they succeed too as their fans last for years .
I could be wrong here , but if big companies like Delta are starting to see a market for Quieter components , then maybe a market shift is happening
While we watch

Earlier in the thread I made the above statement .
If the fan on the new Cooler Master Hyper 48 is an indication of what is happening with Delta 's research , They might just start having their name appear in SPCR forums in a more positive light than in the past ("The Evil Delta Air-raid Siren " )
See this link :- http://metku.net/index.html?sect=view&n ... index_eng3

DrCR · Post by **DrCR** » Sat Oct 30, 2004 7:48 pm

Interesting Delta fan. Glad they're at least making an attempt. It's probably a pretty quiet fan, but I doubt it's SPCR quiet like the Nexus 92.

The Nexus 92
Claimed:
19.2 dBA
1500RPM
27CFM

The Delta from that review
Claimed:
18.5 dBA
"~1400RPM"
28.1CFM

Hum, the RPM to dBA looks about right compared to the Nexus, but do you really believe Delta has a tad quieter fan pushing a tad more CFM than the Nexus? I'm not saying I don't think it's possible, but I will say I'm very doubtful. It's true though, this fan doesn't fit the Delta sterotype.

DrCR

__________
On the side, perhaps you should have posted this as a new topic. I'm now an accomplice of a thread hack. lol

burcakb · Post by **burcakb** » Sat Oct 30, 2004 11:00 pm

May I remind you that the 60mm Delta fans that come on stock AMD coolers are pretty decent when undervolted.

My problem with any brand has been that the bearings are not well-balanced and they click when undervolted. Nexus is the only one (with Globe as second) I've noted that has fans that don't click. Those 60mm Deltas also didn't click when undervolted, so there may be hope there.

ferdb · Post by **ferdb** » Sun Oct 31, 2004 3:31 am

You have to have some spacing between the balls in a bearing so it doesn't bind up, so ball bearings are always prone to those clicking noises. For low noise it seems you need to use some variant of a sleeve bearing and avoid the ballbearings.