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fanless psu?

Posted: Mon Feb 21, 2005 7:39 pm
by ckamc
In my quest to build a silent pc I have come across my last componet.... the psu!

My current system I belive can handle from what I have seen from reviews the antec 350watt phantom... double checked with the HTPC people on now much power my video card i ordered would require... and nicely enought my leadtek 6600 will live.

I still havent ordered my psu however and first looked into all the "silent" psu's that had fans and 40dB at 400watts doesnt sound silent to me.

my general question is... fanless psu safe? I have an idea if i do go fanless to block off the psu from the rest of the case with some sheet metal or something and just allow a little space for the cables and use a silent blowhole fan to pull out additional heat from the fanless psu.

will it work? will it run fairly well?

Posted: Mon Feb 21, 2005 8:28 pm
by ckolivas
Read the recommended PSUs page and it talks at length about what fanless PSUs are good and in each review it talks about how/when they're safe:
http://www.silentpcreview.com/article28-page1.html

fanless psu's

Posted: Mon Feb 21, 2005 9:47 pm
by frankgehry
There are some very quiet psu's with fans so you have to wonder if you really need a fanless psu. You still need fans for the cpu and case cooling. Plus fanless psu's run hot although the antec is better than most. Anyway read the reviews first. - FG

Posted: Tue Feb 22, 2005 5:00 am
by jpsa
Why buy a much expensive fanless psu if you plan on using a fan to cool it? Just get a silent PSU and mod the fans to 5volt...

Posted: Tue Feb 22, 2005 8:55 am
by ckamc
jpsa wrote:Why buy a much expensive fanless psu if you plan on using a fan to cool it? Just get a silent PSU and mod the fans to 5volt...
basically get this psu and mod it to 5v? http://www.endpcnoise.com/cgi-bin/e/NX-4090.html

no

Posted: Tue Feb 22, 2005 9:24 am
by frankgehry
Start looking at the seasonic models. New ones are just coming out. But, this is the typical spcr answer to someone asking about fanless psu's. I would think about it and then do what you want. It won't catch on fire or anything. - FG

Posted: Tue Feb 22, 2005 9:41 am
by MikeC
ckamc has an obvious misunderstanding, he says...
40dB at 400watts doesnt sound silent to me.
40 dB is not quiet fo most people, and it's a common fallacy to believe your system will draw 400W. It just aint so, you'll be in a tiny minority if your system pulls even 200W at max, and I don't know why I repeat myself silly several times a day. :roll:

Just do the reading about real system power requirements that are scattered all over this web site. Just read any recent SPCR PSU review.

Posted: Tue Feb 22, 2005 12:46 pm
by burcakb
Check out Ralf's comment to my Thor rig (see sig)

Take a look at this thread

Posted: Tue Feb 22, 2005 3:10 pm
by frankgehry
Take a look at these threads/polls.
http://forums.silentpcreview.com/viewtopic.php?t=18825
Owner satisfaction survey for antec phantom above.

Owner satisfaction survey for silverstone st30nf below.
http://forums.silentpcreview.com/viewtopic.php?t=19442

Posted: Tue Feb 22, 2005 5:36 pm
by ky
MikeC wrote:It just aint so, you'll be in a tiny minority if your system pulls even 200W at max, and I don't know why I repeat myself silly several times a day. :roll:

Just do the reading about real system power requirements that are scattered all over this web site. Just read any recent SPCR PSU review.
What's a reliable method to measure the peak power draw of our existing systems if we wish to upgrade to XXX PSU?

I'm curious if I can cut out the noise from one of my systems by replacing the current PSU w/ the Phantom but wanted to measure my peak power draw first.

Posted: Tue Feb 22, 2005 6:36 pm
by MikeC
The most reliable way is to get a hold of an AC power meter like Seasonc Power Angel or Kill-a-Watt. Have seen them for as low as $30. How to justify? It's a cool gadget for geeks and greens and penny pinchers.

Another not quite as reliable but kind of interesting way is to measure the AC current that is going into the PC. This requires soldering, an accurate multimeter, a big resistor and a bit of geek cajones... $5 DIY Power Meter

In any case, if your PSU has been reviewed, you can get a pretty good idea of the DC power by looking up the efficiency at the AC power level you measured. ie, if you have a Nexus 3000 and get an AC power reading of 200W, my review shows that you're at aout 72% efficiency. So this means the DC power demanded by your system is ~144W. If your PSU was not tested by SPCR, then for any readings under 300W AC, just assume 70% efficiency. Maybe 75% tops if you want to to err on the high side of power draw.

Posted: Tue Feb 22, 2005 7:35 pm
by ckamc
i would like to thank everyone for their posts and now just looking at all fan psu's now and comparing and contrasting them now

Posted: Wed Feb 23, 2005 10:20 am
by ky
MikeC wrote:The most reliable way is to get a hold of an AC power meter like Seasonc Power Angel or Kill-a-Watt. Have seen them for as low as $30. How to justify? It's a cool gadget for geeks and greens and penny pinchers.
The Kill-a-Watt looks good. We'd have to power down, and plug the Kill-a-Watt in between our AC source and the PSU?