Silent power supplies?

[RussSchultz]

I'm looking for completely silent power supplies.

I've seen one (made by a german company) that is $250!

Seeing as that's outrageous, I'm looking for another one.

Or, in the alternative, making my own. I'm considering buying a good quality power supply, removing the fans, and filling the power supply with a non-electically conductive, but thermally conductive epoxy. (And maybe putting a big heat sink on the back).

Some of the epoxy's I've found are as thermally conductive as:
7x fresh water
3x glass
100x air
1/100x aluminum
(to give you an idea about their effectiveness at moving heat)

The most thermally conductive epoxy/resins have the consistancy of peanut butter when uncured. Some are about 1/3rd as thermally conductive and are more like ketchup.

Any thoughts on how well this might work?

 

[MfA]

No idea if that would work, how about doing the math for a path of the stuff in a solid block with the same dimensions as the heatsink on the MOSFET with the length it would need to get to the external heatsink (which I assume you were planning to attach). Find some numbers for the efficiency of your average PC switching power supply and factor in the power needs of your PC and this should simplify things enough to get some numbers for a conservative temperature delta to expect.

An alternative would be what this guy did. Dunno if this is a good idea for powersupplies with very high switching frequencies though.

Marco

 

[Forbidden Donut]

I've seen fanless power supplies around...gonna have to do some digging to find them though. It is a slow day at work though, so I'll see what I can do


edit: So far all I'm coming up with is a 350 watt one for about $235. I'm assuming this is the same one you found. I'll keep searching though.

 

[AAlcHemY]

I have a 340W Chieftec, and that is absolutly silent.
And you woudn't be the first one to try to watercool the PSU, the only thing is, there has to be a little flow around the heat producing elements.

You could also ( a cheaper way ), just buy a average PSU, and place a 80mm Papst into it. If you still hear it, try to put 7V in stead of 12V on the fan.

 

[RussSchultz]

I'm not sure I need to worry about airflow, since I'm planning on potting the entire power supply in epoxy. As in a solid brick of epoxy with a power supply within it.

Dunno, though. Removing the power mosfets and moving them to a big frickin heatsink on the outside of the case sounds pretty tempting too.

 

[Bouncing Zabaglione Bros.]

I'm not sure I need to worry about airflow, since I'm planning on potting the entire power supply in epoxy. As in a solid brick of epoxy with a power supply within it.

Dunno, though. Removing the power mosfets and moving them to a big frickin heatsink on the outside of the case sounds pretty tempting too.

What are you going to do about the fact that most PSU's are also designed to cool the PC by pulling air through the case? Use epoxy, and you'll still need fans to cool the inside of your case. Even if you watercooled the CPU and graphics card, you still need to dispose of heat from RAM, north/southbridge, and other motherboard components or PCI cards, or you'll get heat related failures anyway.

Try here : http://www.quietpc.com/uk/psu.php

They also have a US site: http://www.quietpcusa.com/

 

[RussSchultz]

The ATX case specification doesn't require air flow through the PSU.

The general path is up from the front of the case, out a fan (pushing out) right below where the power supply sits.

 

[MfA]

As for the epoxy way, even with a very wide&short path of say 10cm*10cm*5cm (which is a generous estimate for a path to a given side of the PSU with a external heatsink AFAICS) and a thermal conductivity of 2 W/m*K you dont need a lot of Watts to push the temperature delta to 50 degrees (10 to be exact). It might work, but the margins are tight.

 

[Bouncing Zabaglione Bros.]

The ATX case specification doesn't require air flow through the PSU.

The general path is up from the front of the case, out a fan (pushing out) right below where the power supply sits.

So you're going to take the fan out of the PSU, and put one in the case right underneath the PSU? Is that actually going to make the whole machine any quieter?

 

[RussSchultz]

Computers generally have:
- 1 or 2 fans in the PSU
- 1 fan in the back of the case
- 1 fan on the CPU
- 1 fan on the graphics card

Some also have:
- 1 fan on the front of the computer
- 1 fan on the north bridge

Obsessive people have:
- 1 fan on the side of the computer
- 1 or more fans on the hard drives

I'd like to get rid of all the fans, but the PSU is next on my list.

 

[MfA]

BTW Zalman is bringing out a completely passively cooled case which is basically one big heatsink.

 

[RussSchultz]

BTW Zalman is bringing out a completely passively cooled case which is basically one big heatsink.

Aaaahhh. A shame it will probably cost $500

 

[MfA]

I wouldnt bet on it being so low

 

[Bouncing Zabaglione Bros.]

I'd like to get rid of all the fans, but the PSU is next on my list.

Hmm, I took the opposite approach, and use a lot of low speed, quiet fans and a good case with all the airflow and hotspots sorted correctly. The noisiest thing is the fan on the 9700 Pro, though the autosensing fan on the CPU can get louder in hot weather when running the machine hard.

The next step for me would probably be water cooling the CPU and graphics card with large radiators and silent fans, but I think I would need a new case to fit the radiators. I've been looking at http://www.wetandchillychips.co.uk/

 

[Saem]

Why not take the powersupply alone and submerge it in a mineral oil bath with a quiet pump?

 

[pascal]

Russ

Noise reduction will not be easy but maybe three fans will be enough for a silent computer.

1 fan for PSU - my recomendation is the ENERMAX EG301P-VB 300W, a friend of mine has it with Athlon XP2400, GFFX, and 3 HDs 7200 rpm working 24/7

1 fan for the case - Zalman ZM-F1 80mm Fan with Quiet Mode Adapter, I am still waiting mine

1 fan for the CPU - If you have an Athlon up to XP2400 than the Glacialtech igloo 2500 (copper) 2800 rpm is better than Zalmans. I had the Diamond version in my previous Athlon, easy to install but variable speed is no go, just get a fixed low rpm copper cooler. I dont know what to do with P4. edited: maybe this one http://www.glacialtech.com.tw/pdf/Igloo 4350light.pdf

for the videocard get a passive cooling. My GFFX is noisy

 

[Basic]

Don't try to fill the PSU unless you find something that conduct heat a lot better than that epoxy. I believe a typical PSU has a 65% efficiency, and a good one maybe 75%. That means quite a lot of power loss in the PSU.

And remember that you haven't got rid of the heat when it's out of the PSU. You need a passively cooled (=not so efficient) heatsink there, and that's some more thermal resistance to go through.

AAlcHemY:
I've got a 360W Chieftech PSU (HPC-360-202). It's not very noisy, but it's still the main noise generator in my PC. Just remember that percieved noise levels are relative, and what's absolutely silent for one, might be far to loud for someone else. Someone who wants to remove the PSU fans are probably rather picky.

I threw out my 80mm Papst fans (speced at 19dB) since they were far to loud for me even at lowered voltage.

Btw: My PC (Sorry for the popups.)

 

[Entropy]

I can vouch for the Nexus NX-3000 300W PSU.
www.silentpcreview.com liked it too, and I can confirm their findings. Minimal fan noise, no hum.

Entropy

 

[stevem]

I just went through a similar process myself in assembling a couple of HTPCs. With air cooling a requirement, the options weren't all that great. I settled on a noise minimisation strategy & picked up Antec Sonata cases, Zalman coolers, & low RPM Antec & Panaflo 120mm case fans. Not exactly silent, but close enough for now. The Sonata 380W S-for-silent power supplies are quieter than my Enermax, but they're no revelation... The DVB HDTV tuners do a reasonable job of distracting me though...