Has anyone ever tried to over-volt a fan?

[Fullmetal Chocobo]

I know everyone is into undervolting their 12v fans to 9v, 7v, and 5v, but what about overvolting fans to 15.3, 17, or even 24v to make them go faster??

 

[2kfire]

Just buy a fan that spins at a faster speed. By over-volting a fan, you will kill it quickly. And, it won't spin too much faster, depending on the original design (i.e. 1.5x voltage doesn't mean it will spin 1.5x as fast due to certain losses)

 

[CrispyFried]

Youll just wipe the bearings out. But if your heart is set on it use an external brick DC power supply. at 24 v the noise a 12v fan will make is amazing

 

[Fullmetal Chocobo]

Originally posted by: CrispyFried
Youll just wipe the bearings out. But if your heart is set on it use an external brick DC power supply. at 24 v the noise a 12v fan will make is amazing

No need for a external power brick. I have my secondary PSU rigged anyway. I could rig the wires to go from +12v to the -12V, and that would feed +24V to the fan. Or go from +12V to -3.3 or -5V for a bit more juice... I'm not really considering doing this--I was just wondering if anyone has.

 

[evilharp]

Sounds like a recipe for destruction to me.

I doubt the wiring and components in most fans are rated to handle the voltage in question.

 

[Operandi]

Originally posted by: tasburrfoot78362

Originally posted by: CrispyFried
Youll just wipe the bearings out. But if your heart is set on it use an external brick DC power supply. at 24 v the noise a 12v fan will make is amazing

No need for a external power brick. I have my secondary PSU rigged anyway. I could rig the wires to go from +12v to the -12V, and that would feed +24V to the fan. Or go from +12V to -3.3 or -5V for a bit more juice... I'm not really considering doing this--I was just wondering if anyone has.

24v would kill any 12v fan pretty quick. Going from 12+ to 3.3- or 5- would likely mess up your PSU pretty bad.

 

[johnnqq]

i read somehwere that overvolting 12-13 volts is safe...but what's the point? just buy a faster fan.

 

[Zepper]

Most of the 12V DC fans are rated to work up to 13.8V (standard automotive charging voltage) but are speced at nominal 12V. One company I deal with has some used Papst, metal frame fans that will run from 12-30VDC!

.bh.

 

[lenjack]

I understand that it has been done at 17 volts...+12 to -5...but that the fans only lasted a few hours.

 

[Zap]

There were some people experimenting with overvolting fans. I don't recall any fans that actually died from it. This was before the current trend with "quiet."

 

[2kfire]

Originally posted by: Zepper
Most of the 12V DC fans are rated to work up to 13.8V (standard automotive charging voltage) but are speced at nominal 12V. One company I deal with has some used Papst, metal frame fans that will run from 12-30VDC!

.bh.

But that's what they were rated to begin with. Also, a lot (if not most) cars charge at 14.4.

 

[Fullmetal Chocobo]

I am surprised to see so many replies of "go buy faster fans" in the forums. If it did not result in damage, would this not be just like overclocking? That said, I don't particularly enjoy the idea of returning these 8 fans, nor replacing them outright... But I guess I will do what I have to do...

 

[2kfire]

Originally posted by: tasburrfoot78362
I am surprised to see so many replies of "go buy faster fans" in the forums. If it did not result in damage, would this not be just like overclocking? That said, I don't particularly enjoy the idea of returning these 8 fans, nor replacing them outright... But I guess I will do what I have to do...

Overclocking DOES cause damage. A non-overclocked CPU should last at least the 3 years they are warranted for, and likely MUCH longer (i.e. 8 year-old Celeron 433 i got). An overclocked, overvolted CPU will likely not last over 5 years. Not many people notice that though because who, that overclocks their CPU, keeps it for more than even 2 years?!?

The thing about fans is that the increase in RPM is not linear with respect to the increase in voltage. You can double the voltage but you won't get double the RPM. You WILL get 4x the power consumption though (P=V*V/R). That means much greater losses and more heat. The fans will die much faster because: 1. the increased voltage will degrade the field windings much faster; 2. the increased current will damage the electronics since they aren't designed to carry it; 3. the increased current will cause more heat, which will also contribute to damaging the field windings/electronics; 4. the higher RPM will wear the bearings out faster; 5. the increased RPM will damage the electronics, since things have to switch faster.
In case you are wondering what electronics I mean, have a read here: http://www.freescale.com/webapp/sps/site/overview.jsp?nodeId=02nQXGrrlPY7r8hv0V
Edit: link is for larger motor, but all DC brushless mtors operate under the same principle

Maybe you could overvolt them, and as they die off, you can replace them with faster/larger fans!
Edit: double voltage = 4x power, not 2x as I had before

 

[Fullmetal Chocobo]

Thanks 2kfire. I won't be doing it. I'm just going to see if I can return them, and if not, I'll have a lot more fans in the side panels that I was planning.

 

[2kfire]

I'll have a lot more fans in the side panels that I was planning.

hahaha lol
well, good luck on those returns, hope everything works out for you!

 

[Jaymes]

Sounds as though you have way too much time on your hands.