Case fans

[Flounders98]

I have a mini-itx case that gets extremely hot inside...i have installed a couple of 40mm fans but they keep failing within a month because of dust or bearing failure. Does anyone have a suggestion on replacement fans? thanks

[Scenic]

Re: Case fans

Delta, Sunon, Adda and Papst fans should last a lot longer than generic ones.
most of them aren't the quietest though..

edit: oh and ball bearing fans usually last longer than sleeve bearing ones..

[momaka]

Re: Case fans

Running the fans at a lower voltage (5v-7v) would also help their life (especially small fans like the ones you have), however they will be pushing less air, which might be a concern for you. If you can fit bigger fans somehow and run them at lower voltage, that would be the best thing to do.
As for dust - all fans catch dust eventually (those that spin slower catch dust slower), so you'll just have to clean the computer regularly when you see dust accumulate on the fans.
...
By the way Scenic, I think you forgot Nidec (they seem to be ok too).

[gdement]

Re: Case fans

I have a bunch of DFB0412M fans I use (40mm). They seem very reliable, no failures yet.
They're made by Delta, although mine use Fonsan as the brand name.

Several people seem to be selling them on ebay. I got mine a long time ago, not sure if it was from any of those sellers.


Caveats:
- They're 2-pin fans, and the plug doesn't fit a typical 3-pin connector properly. But it works if you remove the shroud on the motherboard side, bend it, or whatever.
- They're 20mm deep, which is probably a good thing for reliability but you'll need longer screws.
- They run at 6000rpm, so not quiet. For one computer I soldered some resistance into the wire to slow it down. Be mindful the fan draws about 1W so a single cheap resistor won't handle that. I think I used 8x 620ohm 0.25W in parallel, just because I already had them.

[Scenic]

Re: Case fans

By the way Scenic, I think you forgot Nidec (they seem to be ok too).

yeah.. my bad... haven't seen those for a while.. that's probably why

oh ...Panasonic/Matsushita fans ("Panaflo") also seem to be very reliable.
but they make some strange motor noise while running... at least the ones i've got here o.O

[kc8adu]

Re: Case fans

dont forget sanyo.

[linuxguru]

Re: Case fans

NMB, Panaflo, Nidec, Papst in decreasing order of my preference, ball-bearing only. Not sure if you can get 40mm sized fans in all these brands. I think Panaflo and Nidec have merged some years ago; Panasonic has acquired Sanyo recently, but may retain the Sanyo brand.

[Wizard]

Re: Case fans

Thumb up on NMB, Nidec and one San Denki (also makes fans for intel). Panasonic have been manufacturing sleeve fans only with their non-standard design on the bearing.

You'll need to find a way to fit 60mm fan and slow it down to around 5V to 6V. Cuts down on whoosh and whining noise.

Cheers, Wizard

[bgavin]

Re: Case fans

For all my case fans, I switch the Molex connector leads from 12v to 5v.
This slows down the fan for longer life and makes it almost dead silent.

Sleeve bearing fans are fine as long as the run with a horizontal axis.
Vertical mounting of sleeve fans results in a much shorter life span.

All of my clients 24-hour servers run Panaflo fans. Several are running more than 10 years. I have never had a Panaflo fail.

Panaflo makes 40mm fans as the FBA04A12x1A series.
"X" is L(ow), H(igh), U(ltra high) RPM

[Krankshaft]

Re: Case fans

I can vouch for Panaflo (Panasonic - Matsushita Electric fans) too.

They use ball bearings and are built to last long no wussy sleeve bearings here.

[Flounders98]

Re: Case fans

Thanks for the info guys...now time to do some research.

[ChuckG]

Re: Case fans

If you want to go completely off the beaten path, consider an AC (line powered) fan. Rotrons are still made and will probably last forever.

A bit noisier than the usual DC fan.

[PCBONEZ]

Re: Case fans

AC fans in case -> EMI.

[ChuckG]

Re: Case fans

AC fans in case -> EMI.

What sort of EMI and what are the practical consequences? No one uses CRT monitors or floppies anymore and hard drives are pretty much impervious to the field generated by a small fan.

Unlike a DC fan, the AC fan isn't putting noise onto your DC lines. The original 5150 used an AC fan in the PSU.

Just curious if you have some hard data for your statement.

[Wizard]

Re: Case fans

AC fans is well protected on magnetic shielding and since AC is sine wave, AC fan uses split phase armture with squirrel cage cup rotor with fan blade attached, no transistors to speak of. Therefore no sharp turn off and any spikes aren't there.

[PCBONEZ]

Re: Case fans

This is extremely basic electronics knowledge.

What sort of EMI and what are the practical consequences?

Unshielded AC motor -> EMI
EMI -> RF bouncing around inside case.
RF bouncing around inside case -> RF picked up in PCB traces.
RF picked up in PCB traces. -> RF in signals.
RF in signals -> Corrupt data.

No one uses CRT monitors or floppies anymore and hard drives are pretty much impervious to the field generated by a small fan.

impervious?
-> Not even close.
If there isn't enough distance DC fans will even affect them.

The original 5150 used an AC fan in the PSU.

You know that steel box the fan is mounted inside? Called a PSU.
-> EMI Shield.

Just curious if you have some hard data for your statement.

How about having been an electronics tech for 27 years.
I suggest you google EMI, RF, and AC motor.
.

[PCBONEZ]

Re: Case fans

A shielded AC fan will have a metal blade and frame.
That's the shielding.

The wires running to it won't be shielded unless you do something to make them so.
.

[ChuckG]

Re: Case fans

This is extremely basic electronics knowledge.


Unshielded AC motor -> EMI
EMI -> RF bouncing around inside case.
RF bouncing around inside case -> RF picked up in PCB traces.
RF picked up in PCB traces. -> RF in signals.
RF in signals -> Corrupt data.

Whoa--that's a big leap, fella! A shaded-pole AC motor puts out a 120 Hz magnetic field (peaks on each half-cycle). Scarcely RF--and actually well-contained within the field windings, with no sharp commutation transients.

Magnetic, perhaps, but not RF.

Not even close.
If there isn't enough distance DC fans will even affect them.

DC motors must commutate somehow to produce a torque. Whether with brushes or using sensors, there are sharp transients, which produce substantially more RF than any AC shaded-pole motor.

Back when the first 5.25" floppy drives were just coming in (about 1976), we put a couple of Micropolis 100 tpi units in place of the Qume 848 8" drives that we were using. The Qumes, with their AC spindle motors produced not a hiccup in the video display sitting on top of the drive box. But the Micropolis units with their DC spindle motors made the display jump. We eventually put a substantial steel shield around the drives.

How about having been an electronics tech for 27 years.
I suggest you google EMI, RF, and AC motor.
.

I've got at least 10 years on you--and most likely a couple of degrees.

How about some math to prove your point?

[linuxguru]

Re: Case fans

There's nothing about a DC motor that makes it free of RFI/EMI. If it has brushes, you can probably pick up the commutator spark-gap interference from a mile away. If it is brushless, there's still a whole bunch of switching electronics that's driving the armature. Either way, there's some RFI/EMI around. The only reason it's not a big problem in a PC is that there are multiple sheet metal cabinets in the way, and most of the electronics in a PC is digital with the exception of some head R/W electronics and display electronics, both of which are very carefully shielded.

[PCBONEZ]

Re: Case fans

I've got at least 10 years on you--and most likely a couple of degrees.

How about some math to prove your point?

Degrees mean you know how to pass tests.
Congrats!
You know how to pass tests!

My point is well known for generations, well proven, basic knowledge.
- Yet in your years you don't know a thing about it.
If I'm going to teach someone it will be someone with some comprehention of the subject.
I have better things to do than teaching rocks.
How about you waste your own time with it.
.