Complete '24/7' pc running on one 90mm fan - outside!

Show off your quiet rig.

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Complete '24/7' pc running on one 90mm fan - outside!

Post by Remco_Hitman » Tue Oct 31, 2006 12:53 pm

Hi guys! I'm new to the forums but I have been reading it for a few weeks. Great stuff :)

Now I would like to present my own silent pc 8)

It is basically a simple pc built from parts left over from various upgrades. It sits outside on my balcony, in a specially designed weatherproof fiberglass case. Designed by myself, obviously ;)
The whole pc has only one fan, a €9 90mm outtake fan. No fancy cooling equipment installed, no passive cooling towers, no nothing :shock:

Okay, I know what you're thinking. I'm nuts.

I agree :twisted:

But I must add that it's been running great since July 2005. All components are healthy and cool. It started out as a do-or-die test. The components were pretty much redundant anyway. But why outside? The PC wasn't always this silent. Before, I had it suspended in the hallway above my door. Last year I moved and had to find another solution. The only thing close enough was the balcony door. I figured what the hell :D
Every peripheral is attached through about 12 feet of extensions per cable. The DVD rewriter has an IDE to USB module attached and is mounted in my monitor stand, as is a USB2.0 hub.

The specs:
AMD Athlon 2400+
1024MB RAM 333MHz
GeForce2Pro 64MB
Two lousy HD's
PSU: 230W brandless from the stoneage

The case is made with fiberglass and is weatherproof in the sense that even horizontal rain can't penetrate the case. It's also airtight, apart from two instances: a ducted intake and an outtake in the form of a 90mm fan. As the fan blows warm air out, the ducted intake draws in fresh air directly across the CPU heatsink. This is the heatsink which came free with the CPU. I just unscrewed the noisy fan and threw it out :D The stream of air is then led across the naked PSU, which I removed from it's casing and seperated from it's noisy fan. After that, the air is pushed out by the fan running via a 5V/12V switch.
Since the mobo was already fanless and the VGA is now passive (I also forcibly removed the fan from that), the whole rig is cooled by the one fan :D

The results are very good! The CPU runs at ambient + 20C, currently 29C. The northbridge is one degree cooler. Harddisks are running at 37C at the moment.

Okay, some notes.
This is not a performance gaming rig. I have a seperate gaming rig which is very powerful and loud :)
Silently cooling this download/email/MSN pc isn't very hard. Cooling it with one 90mm fan is something else, mind ;)
Also, the PSU is using the same airstream as the CPU. This is not a good idea, but it seems to work alright. However, it doesn't work so well with the fan at 5V. It doesn't take long for the PC to switch off, probably due to the PSU getting too hot and losing output as a result. The CPU is fine at 5V though, ran steadily at 47C.
Another thing is humidity. The air drawn in will certainly have a higher humidity than you'd get in the house. Truth be told I'm not sure what the effects are. I've seen no evidence of damage when I revised the pc after a year. Humidity is of course relative. The air inside the case will be around 20C, quite a bit higher than ambient. That means that the relative humidity will drop as soon as the air enters the case and gets warmer. I think the result is a climate inside the case which isn't harmful to the components. We'll see in another 12 months, when the next revision is due :D
As for the noise? There isn't any :) It's outside, so the teeny bit of noise generated by the single fan is inaudible from my workstation. At 5V, the HD whirring is the only sound you can hear, and even that only when you put your ear right by the case. Not sure whether it's worth my while to work on getting the pc to run stable with the fan at 5V.

Comments are welcome! 8) 8)

But first some pics!

Last edited by Remco_Hitman on Tue Oct 31, 2006 2:15 pm, edited 1 time in total.

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Post by NeilBlanchard » Tue Oct 31, 2006 12:58 pm

Hello & welcome to SPCR!

Kewl set up! Did you fabricate the case yourself?

Some of us around here are nuttier than'll fit right in! :P

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Post by Remco_Hitman » Tue Oct 31, 2006 1:02 pm

NeilBlanchard wrote:Hello & welcome to SPCR!

Kewl set up! Did you fabricate the case yourself?

Some of us around here are nuttier than'll fit right in! :P

Thanks... I guess :D

Yes, I forgot to say I built the case too. It came out really ugly, because I used outdated gelcoat and ran out of spraypaint halfway through lol...
I'm usually quite the perfectionist when it comes to my fiberglass projects, but this time I figured: "out of sight, out of heart" :wink:

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Post by a_punker » Wed Nov 01, 2006 8:42 am

give your case an IP rating!
This is how industrial enclosures are rated for wetherproofing. IP00 = totally open and not waterproof to IP68 = drop it in the deep ocean. I'd say your case was IP13.

So, have you had any small rodents/hobos trying to nest in it yet?

What is that green PCB mounted at right angles to the motherboard - is it your case-removed PSU?

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Post by sanse » Wed Nov 01, 2006 10:28 am

seems like a dutch 'fietsenhok' (bicycle-shed) on one of the pictures. :)

nice project. very original.

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Post by Remco_Hitman » Wed Nov 01, 2006 1:13 pm

Hehehe! It is indeed a typically Dutch fietsenhok. Well spotted :)

This is really cool! I'd agree on a rating of 13. My sea kayak's hatches would be rated 67 8)

Anyway the PCB you spotted is indeed the PSU. It sits on a 2nd floor built into the case above the mobo. The PSU sits in a space about as big as a standard PSU case, and it's basically the main channel to the outtake fan. That's how the PSU recieves sufficient airflow.

And no, I haven't seen any birds, but it does appear to be a pretty elaborate yet succesful mosquito trap :D

BTW it has gotten quite a bit colder here since yesterday. Both the CPU and northbridge are now running at 25C. HD's are now at 32C. I'd say ambient is 5C.

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Post by a_punker » Thu Nov 02, 2006 9:20 am


perhaps you could post some outside/case/CPU temps every couple of weeks. Winter is coming and the first frosts are appearing (in the UK anyways).

A well made and well positioned outdoor case could make effortless cooling. Humidity and spider ingress would probably have to be monitored!

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Post by andyb » Thu Nov 02, 2006 11:00 am

Remco, where do you live, I'm guessing northern europe.??? You dont have a signature, might be an idea to add one.

What are temps like in the Summer, and does the PC get direct sunlight at any time of the year.???

Damned cool PC.


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Post by qviri » Thu Nov 02, 2006 11:04 am

He lives in the Netherlands.

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Post by niels007 » Wed Nov 08, 2006 5:58 am

Remco didn't listen to me when I suggested white is the only colour to paint anything in that sits outside :) ; I believe it did get too hot in summer but that was with the old 'multi fan' setup, hence the white bed sheet over the 'balcony' (wouldn't call it that!) railing.

Its overall quite insane this case :D (in a good way!) :)

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Post by matva » Thu Nov 09, 2006 8:57 pm

thats pretty hardcore.

how do you manage to keep bugs and stuff from getting inside? it seems as though you are not using any filters.

very kool, but i have to say, i hope a bad storm never comes your way... and if it does i hope you're there when it hits!

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Post by a_punker » Fri Nov 10, 2006 7:28 am

so long as its not made of cardboard like it looks (!) then a genuine heavy downpoar won't be too much trouble.

I reckon morning Dew/frost/humidity is going to be the ultimate poblem.
Moving parts will suffer first.

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Post by Remco_Hitman » Fri Nov 10, 2006 7:41 am

haha! Well we don't get bad storms on the Floridian scale over here, but it has gracefully survived last week's 10BFT winds and ferocious hailstorms. It's seen some biblical downpours through the last winter too.

The only problems I've had came during last summer's heatwaves. It was a particularly hot summer this year. However, problems only arose on the three hottest days, when pc's across the country were suffering. Not really an issue for me. I put up the white cover last summer to protect the case from direct sunlight. Worked like a charm. That side of the building catches direct sunlight from noon till sundown so a bit of shade for the old PC was definitely needed.

Condensation resulting in dew or even frost won't harm the pc at all. Condensation only accurs on cold surfaces, while the whole case is warm.

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Post by Remco_Hitman » Sun Nov 12, 2006 2:52 pm

Oh and here's a little schematic I drew up coz I was bored :P


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