overvolting fans?

i searched around trying to find this, people just seem to alude to it...not really explain it. i could be blind as a bat, but feh.

i have 2 120 mm antecs that i want to move more air. they are 12 volt fans and i want to over volt them to spin faster. how would i go about doing this? i think they move 20 cfm at stock speed which is about 800 rpm. they have no temperature sensors, so this is as good as they get =\

20cfm for 120mm fans? doesn't sound right..
overvolting doesn't concern the fan, its all about the power supply.
since u can't do that (unless u want to kill all the 12v components in your computer).
overvolting ur fan also means that the life of ur fan will decrease. if you overvolt it enough, it just might fry right then and there.

so whats the best solution?
get new fans
http://store.yahoo.com/svcompucycle/en12vasphipe1.html

Over volting will kill your fans. Sometimes it will kill them very quickly.

I searched and found 28 results and this thread:

http://forum.oc-forums.com/showthread.php?s=&threadid=216263&highlight=overvolting+fans

It gave a link to this article on OC.com:

http://www.overclockers.com/tips808/

I expect these fans to be replace soonish. just experimenting. I wonder how long these fans would last at 15 volts. that would certainly speed them up enough to move more air and wouldnt be nearly as stressful on them as 24 . i never wanted 24 volts, 12-15 yes, but man....

I intend to replace these with two evercool or ystech 120x25 mm fans soon when i get like $60 to throw into it. the evercools move 80 cfm at 30 db where the ys tech is 110 cfm at 41 db. if i had a vantex nexus or somthing, i could just get the ys fans and run them down to desired noise levels. one thing to be happy about is that these fans are inaudible period. all i can hear from my overclocked 2100 now is the whooshing of air. its very soothing.

buuut, more airflow would be nice when i feel like 2400 mhz again. this is why i think to volt mod. i dont care if the fans die, i have plenty of 92 mms i can mount in place if they do.

would be interesting to over volt a tornado to 17 or 24.... that would be disguesting noise but airflow O_O

Dood get some fans like Papst or Sanyo Denki,s .Thats what the pro,s use.Buy once and be thru with it.But I know you like to experiment alot. Just a thought. THE FANMAN

OR at least some Panaflo's

u can crank it up to 15v without any problems..
i really doubt the evercool fans are 30db, probably more like 35 or more. not even manufac. measures the sound the same way.
YS Tech is a very good fan.
>20dba is inaudible, atleast for me

I volted them up to 15 volts right now, its still inaudible and definatly moves more air. just for kicks i tried my smart fan 2 at 15 to get a taste of what a tornado 92 mm must be like.... that wont be happening <_<.
i was thinking of panaflo fans simply because they are available, they move lots of air, they are silent and they are reliable. I can mount one as exaust, but for intake, i can only use 120x25 mm fans.

I really shouldnt be complaining about the flow of these things. my system stays under 40º @ 2000 mhz with them which is as good almost as when my case was open. over volted, they probably dont spin fast enough to make a major difference but ill just have to see when i crank this thing up again.

I cant really tell what my ambient temp is right now, but im going to assume that it is about 25-30, its winter and the gas is on.

with case open, and my fan at full bore, my load temp doesnt exceed 35ºC under prime 95. if i close up the case, run my smart fan 2 at 3700 rpm, she stays under 42ºC. case open with 3700 rpm fan is 38º. much less noise and still acceptable cooling. clearly, i need more air flow to my case, but its not too bad i guess. when i remove the load, my cpu cools to idle temp withing a minute, so somthing must be working.


are the ys tech 120's mag lev?

Valk,you said you were looking for a nice cent. blower! Well I think
I found it. THE FANMAN

FAN LINK

Valk, if or when those fans die, you should come back in this thread and let us know. We can make it a little experiment.

The fans archilochus linked to look nice, Granger also carries some. You should be able to find them on their website, and you can order direct from them if you can place an order through your company or a friends. I have a Granger blower.

I think the led's on my front fan will burn out faster than the fans at this rate. they arent even getting warm... meh, i think i should snip those anyway since i have a red *more pink =\* and a yellow *.... kinda greenish* cathode in my machine. blue led fans just makes it look TOO colorful.
ill let you know when they die though.
that blower looks pretty sweet. i so want to get some cent fans going. I can mount it where my 92 mm radeon fan is right now and simply duct it into my sk7. would be interesting to see how my cpu likes 275 cfm. would make me wonder why im phucing around with this pansy 80 =\

of course, those dc motors are quite... large.. im sure it would be impossible to run those internally due to the magnets in the motors. im sure that motor weighs as much as my case

oops....

Hehe, I had a little accident a few days ago...

I upped the voltage on my variable PSU by hand.. a little too quickly.. just wanted the damn fan to start today!!
I'm not sure what voltage I hit, probably around 16-18V.
The fan died instantly. It was a cheap 80mm fan marken "Cooltimum" purchased in the states.

Remember guys, these fans are more "electronic" than ordinary DC motors(with brushes)

These has a controller circuit built with IC's and they have a finite breakdown voltage.

So, I don't think it's the increased current that kills it, it's more of an internal short-circuit. You pass a certain point and the silicon just gives way to current and burns up internally.
All coils and such are most probably ok, it's just the coil driver that's burnt.

During summer it was really hot in the robotic lab and my friend had couple 120 mm fans (or maybe something bigger, forgot). It was rated at 12V. The circuit protoboard we had for prototype circuit designing only had -15, -5, 0, 5, 15. Needless to say we were running these fans 15, 20, sometimes 30V. They spinned like crazy and make a lot of noises. But you got to watch out for your fingers though.

Valk ,the bug got me.Thanks IMOG,I forgot about Graingers.They
are down the road from me.Here's a link to a nice little HS fan I found.I would have to physicaly see it to see if it would work.It has a nice mounting flange.Excellent pressure and cfm.Only draw
back is its a AC motor.Oh well, such is life.Might be to heavy for
air travel. THE FANMAN

FAN LINK

go for it man I hooked mine up at 50 volts and it only took 3.2 seconds for them to explode LOL. But serious ly I would not do much more then 14 volts

http://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611630892&ccitem=

one end blows directly into your cpu. build a little plastic box around the base of your cpu socket that captures all the air around it and sucked it into the secondard stage, which blows it out of your case all the head form your cpu is expelled from the case without interacting with anything
this looks like a mean one too, perfect fit to a 80 mm cpu fan, at least its outlet.