Quieting PSU, could this work?

e-ghost · Post by **e-ghost** » Wed Jun 18, 2003 12:25 am

I know this is not the first time this topic is treated, but having searched for a long time I just couldn't find the answer to my question.

This is not the first time I atempt to silence a PSU. I used to have a 250W Skyhawk for my old PII, which came installed in the case. After lots of years of not cleaning it at all, the fan stoped working, so I had to change it. I bought a thermal controlled Cooler Master fan. OOOhhh!! It was amazingly quiet, that's when I started in my quest for silence.

But PII's are not forever (thank God), so I updated to a P4. I wanted it to be silent, so I bought an AOpen board with silenttek. It's a 1.8GHz Northwood P4. The CPU stays quite cold with the fan completely stopped when idle (42ºC).

I decided to buy a good silent PSU, for which I had to look in every shop of my city (I live in Spain). Here there's no Antec, no Q-technology, no nothing. In the end I bought a 420W Levicom PSU, a german company. They claimed it to be very quiet, and it is quite quiet, but I WANT MORE.

It has two thermal controlled fans, but theres no way of finding the thermistor, it's not like the Enermax reviewed at SPCR, so before messing it up too much, I'm gona give it a try with just one fan. The fans run at 2100rpm after over 10 hours of normal use.

Here is my question (at last...). Do you think it could stay cold enough with just the inner fan, instead of the outer one? (sorry about the crappy explanation of my question

) Has someone tested something like that? The PSU is 2 days old, so I want it to last at least 1 week before it explodes...

I guess it would work fine just with the outer fan, but I think the inner one will be quieter because it's more inside the case...

powergyoza · Post by **powergyoza** » Wed Jun 18, 2003 12:30 am

hey there,

You'd probably be just fine to take away one of those fans. In your situation, my preference would be to keep the outer fan.

pingo · Post by **pingo** » Wed Jun 18, 2003 5:03 am

e-ghost, I was in a similar situation: could not get a Fortron or Seasonic here in Italy for a reasonable price.
So I got a cheap PSU with only 1 fan exhausting and with the intake side of the PSU case completely drilled.
I opened the PSU, removed the stock fan, cut away the fan grill, mounted a Panaflo L1A OUTSIDE the PSU case on rubber rings with nuts and bolts.
Maybe a Panaflo M1A would be safer (as MikeC recommends).
I got the rubber rings in a high fidelity shop, they had also completely rubber fan isolators. But they would left the fan about a 1.5 cm away from the PSU case, too much air turbulence I think.
And the E.A.R. silicon fan isolators are too expensive to get from USA.
Then built a very simple electronic circuit to thermal control the fan , screwed it inside the psu case and placed the thermistor to control the air exhausting from the psu.
Also added a duct to bring fresh air from the front of the pc case (upper the cd rom drive) to the intake side of the psu.
I’ve reached excellent results in term of noise. The fan with CPU idle is spinning at 6 volts and is really inaudible.

Many thanks to powergyoza: I’ve took lots of ideas from his posts.

frosty · Post by **frosty** » Wed Jun 18, 2003 6:40 am

Great read here so in theory one could run your psu fan at slower than 12v and get away without a burnout?

pingo · Post by **pingo** » Wed Jun 18, 2003 7:09 am

frosty. I'm not an expert, but best PSU have a thermal control circuit. So the fan runs at 12 volts only when really needed.

frosty · Post by **frosty** » Wed Jun 18, 2003 9:57 am

Thanks yes I will checking into getting an Antec.

madlee · Post by **madlee** » Wed Jun 18, 2003 3:38 pm

I'm going to replace my Nidec BetaSL:

Model DO8T-12PU
DC12v 0.22A
44.14 CFM
34 dBA
3400 RPM

with a Panaflo FBA08A12L

however, I'm a bit concerned about the considerable difference in CFM rating...

It's too bad that the fan manufacturers aren't more accurate with their rating scheme that way it would remove a lot of guess work...