running a fanned psu fanless- too risky?

porkchop · Post by **porkchop** » Mon Jul 05, 2010 3:59 pm

i've got a very low power pc and it doesn't see much stress - would my psu be ok in the long run without airflow?

the psu will be open so convection will help, and i guesstimate the power consumption to be around 35w in idle, the psu is an 80+ 350w unit.
one of the main reasons i'm interested in trying this now is because its winter and its really, really cold, there's no doubt i'll have to put a fan back in come summer or even as early as spring.

...

i guess the real question is- in this world of fanless 90w laptop bricks, fanless 450w atx psus and seasonic psus which stop the fan at low load, what am i risking by pulling <50w from a decent psu and removing the fan?
(i understand that components inside the fanless units are most likely more resistant to heat- but is the difference really that great?)

Redzo · Post by **Redzo** » Mon Jul 05, 2010 4:14 pm

porkchop wrote: (i understand that components inside the fanless units are most likely more resistant to heat- but is the difference really that great?)

yes it is.

tim851 · Post by **tim851** » Mon Jul 05, 2010 5:46 pm

I did this a couple of years back. I connected the fan to an external fan controller that could stop it. That was in 2003, the power supply was probably something in the 350w range, the system was an Athlon XP with a Radeon 9000 Pro vga card. Didn't come close to 35w idle. It ran fine passive, as long as I didn't tax the system. If I started gaming or such and forgot to start up the fan again, I'd get a reboot.

I'm pretty sure you can do this today.
Although for as long as I did this, I had mixed feelings about it.

Plus, you gotta wonder why there aren't as many passive PSUs on the market now, as there were a couple years ago. Maybe too many PSUs failed and it turned out to be a losing game, despite the high price.

ntavlas · Post by **ntavlas** » Mon Jul 05, 2010 8:13 pm

It should work as long as the psu is not above a major heat source and there`s plenty of room for convection to work.

Plus, you gotta wonder why there aren't as many passive PSUs on the market now, as there were a couple years ago. Maybe too many PSUs failed and it turned out to be a losing game, despite the high price.

I think the reason why we see less fanless psu has more to do with cost than failure rates. Anyone who needs a 400 watt psu most likely uses a few fans anyway so why pay the premium. This leaves us with htpcs/sffpcs which are often better off with a pico psu or similar.

Post by **MikeC** » Mon Jul 05, 2010 9:39 pm

porkchop wrote: what am i risking by pulling <50w from a decent psu and removing the fan?

Not much but it is definitely subject to higher higher stress. Personally, I would not pull or stop the fan. Slow it down or swap it for quieter.

Luke M · Post by **Luke M** » Tue Jul 06, 2010 10:06 pm

If you are relying on a case fan to cool the power supply, a concern is that it may work fine with the case closed, but not with the cover off (since there won't be any airflow).

porkchop · Post by **porkchop** » Wed Jul 07, 2010 5:38 am

actually the psu/case fan is the only fan in my system, i have an ssd too so removing it will make my pc completely passive. my case is open- all sides are left off.

i'm still thinking about it. i've tried moving the psu around the case but it has proved more difficult than i thought

running a fanned psu fanless- too risky?

running a fanned psu fanless- too risky?

Re: running a fanned psu fanless- too risky?

Re: running a fanned psu fanless- too risky?