Computing Chimney?

Enclosures and acoustic damping to help quiet them.

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ddrueding1
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Post by ddrueding1 » Sun Oct 28, 2007 3:04 pm

I appreciate your attempts at ASCII art to describe something, but I can't see it thought my hangover.

Are you talking about angling the motherboards themselves into the airflow? Putting baffles above/around components to direct airflow onto the components?

ddrueding1
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Post by ddrueding1 » Sun Oct 28, 2007 3:05 pm

Oh, I was also playing with the idea of casting it from concrete instead of building it from wood. That should stop the resonance issues ;)

FlorisNielssen
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Post by FlorisNielssen » Mon Oct 29, 2007 2:40 am

Euhm... Heavy?

He tries to say you should direct the airflow to the components. Now, especially at motherboard-height, the air which goes through the middle (a lot) is quite useless. You should direct it to the motherboards.

ddrueding1
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Post by ddrueding1 » Mon Oct 29, 2007 7:44 am

Yes. Heavy. ;)

I'll give wood a try first, something like 3/4" Oak? Perhaps with a different wood in the "working" parts of the box, so I can screw/unscrew bits without damaging the main frame.

scdr
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Post by scdr » Mon Oct 29, 2007 5:00 pm

I was wondering about weight also - specifically, how stable is this thing
going to be. 7' tall, about 18" base, made of heavyish wood (or watever).
Whole heap of drives a ways up there.
Of course the UPS in the base should help to stabilize it.

I assume it will be strapped to the wall, since you live on the
ring of fire (as I do).

ddrueding1
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Post by ddrueding1 » Mon Oct 29, 2007 9:10 pm

This idea is evolving as I look/plan it more. It's looking like I'll be buying a house soon. :shock: So I have the option of doing building modifications!

I'm playing with the idea of building it into a wall unit/desk configuration. I still want it central to the house, as the HTPC outputs HDMI to 4 different rooms, and I don't want the runs to be that long. But If I'm building it in, size and weight are not relevant at all. So:

What is the best way to get air in and out silently?
What is the best way to direct that air onto components?
What are the materials I should be considering?

Thanks for all the answers and suggestions so far.

Celoth
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Post by Celoth » Tue Oct 30, 2007 3:59 am

Nice project!

I would worry a bit about the top components getting too hot myself, so maybe try somthing like this:

Image

Double walled chimney, with fans blowing in cool air from the side, directly on to the components as you place them up along the chimney on the inside. If you arrange it so the hot air can rise up through the middle without too much hindrance, it might work. You can even place a barrier (maybe angled upwards a bit) over each component. That way the hot air won't just go directly up to the component above it, but is forced into the middle. Or simply place shelves up along the sides and let the shelf itself be the barrier against hot air from below.

The double walls will probably further dampen the noise.

The inner wall can be plywood, or something cheap, since it won't be seen from the outside, and can be replaced much easier than the more expensive oak (or whatever you choose) if you mess up. Heck, place the inner plywood enclosure on wheels so you can pull it out in its entirety, do your modifications and push it back in again. :)

It'll make the whole thing a bit bigger, but if you're building from scratch in a new house anyway.....

Make it big enough to stand in and you'll have your own walk-in PC!

Of course, you could also make yer own little serverroom instead, with airconditioning, and place terminals wherever you want in the house.

ddrueding1
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Post by ddrueding1 » Tue Oct 30, 2007 9:13 am

The thought was to put the components that were more temperature sensitive (HDDs) on the bottom and ones that were less so (networking gear, PSUs) on the top. Also, I think if I get enough airflow through the chimney, the temp differential between intake and exhaust will not be significant.

I was thinking of turning an entire closet into a chimney, but I want the cross-section to be small enough that most of the air passes over components on it's way up. That would mean having it just wide enough for opposing motherboard's GPUs and HSFs to meet in the middle.

ronrem
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Re: Computing Chimney?

Post by ronrem » Tue Oct 30, 2007 12:13 pm

ddrueding1 wrote:What is better than cooling a computer with just one fan? Cooling several computers with just one fan. ;)

I'm sure I'm not the only one with more than one computer at/near my desk, and I've decided to take a holistic approach to cooling them.

Basic concept:

Wooden Chimney, approx 7 feet tall, ~14" on a side internally.

Starting from the bottom:

1. Intake
2. Filter
3. Sound baffle
4. 36cm fan
5. Suspended hard drives
6. Surface mounted motherboards with passive tower heatsinks
7. Sound baffle
8. Exhaust

Pretty simple, really. The concept is to create an acoustically isolated windtunnel, and put all the stuff in it. A very simple model of a single-computer version might look like this:

My first question is, where can I buy a really quiet 36cm fan?

I welcome any thoughts on this project before I begin in a week or so.
Love the concept....though 5-6 ft tall probably works as well.

the 360 mm fan can be had WITH a case at around $50....you do get handy switches..LEDs..back panel...a cage you could cut free and use to suspend several drives. You can find the 250 mm fans at $20-25 seperate.

So far....no seperate 360mm

I'd have the cooler mobo/CPU lowest...then the warmer one. Fanless Zen PSU's up top? Generous open space at the top so the PSU's get a mix of air from the low mount fan-but also the air from the room.

suggest 2 decent size tires and a handle...kind of like a moving dolly. This would not really take a lot of floor space---but even at 6' tall you don't want it too top heavy and easy to tip.

If you want maximum bling...mount an LCD monitor in the box or a sheilded subwoofer! :shock:

ddrueding1
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Post by ddrueding1 » Tue Oct 30, 2007 1:37 pm

Right now I'm playing with 2 designs. One is counter-height without baffles and a tighter interior space, the other is full-height to the ceiling. Anything in between doesn't really give me much space back and makes things more awkward inside.

120mm fans will do fine I guess, better selection at least.

ddrueding1
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Post by ddrueding1 » Thu Mar 20, 2008 8:24 pm

I finally got around to building it!

Not according to the original plan, but not far off.

Noise is excellent, and will be increased with some damping/absorption materials.

Comments and questions welcome.

tufish
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Post by tufish » Fri Mar 21, 2008 1:06 am

it's..... insain

jaganath
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Post by jaganath » Fri Mar 21, 2008 2:03 am

great job. very stylish too. what are your temps like?

ddrueding1
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Post by ddrueding1 » Fri Mar 21, 2008 7:24 am

jaganath wrote:great job. very stylish too. what are your temps like?
Not bad, but not as good as I'd like. Everything but the chipset is below 40C at idle. I've been playing with overvolting/overclocking the CPU to as high as 3.8Ghz and 1.6v, and that sends it's load temp to 77C. The Northbridge is just stupidly hot no matter what; even with an 80mm tri-cool on high it is in the mid-50C range. I just set the fan to low and stopped worrying about it.

The hard drives are certainly the noisiest bit. Some interesting information:

Distance from hard drives to closest case opening: 3ft

Distance from nearest case opening to my ear: another 3ft

Even though I'm sitting right next to it, it's like the computer is 6ft away.

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