TEC as a case cooler for total silence

[Shoebox9]

Hi All,

INTRO:
I suffer from some sort of increased susceptibility to tinnitus. Whenever I’m around fan heaters, PC fans, fluro lights (they tend to emit a high pitched noise as the ballasts in them age), etc, I get a loud ringing in my hears for hours afterwards.

Because of this I have strong motivation to build a really silent system, but the system also needs to beefy (ie X2 4800+), as I'm a photographer, and editing large photos is part of how I make my living.

Q) So, why not just passively water cool the hot bits & leave the case open? A) h/drive noise, and the high pitched whistle/scream most PSUs & mobos seem to give out.

Stability is important. Mobo condensation insulating, and play-till-it-pops, has low appeal at this stage.
Portability is not important, and I can fabricate stuff out of wood where needed.

MY GOAL: To build a powerful, but totally inaudible system, that will be reliable & stable.

MY PLAN:

* Cool the CPU (& maybe NB, GPU?) using water blocks, a pump, & a large copper/brass car water radiator, with no fans, attached to a wall. I'll use 2 radiators if needed, but plan to start with one.
* Use an old bar fridge as a case. Advantages- it is air tight (I presume), offers reasonably good sound dampening, and is free. Disadvantages- it is big, and I'll need to cut off the external gas cooling pipes & lie it on it's back, so it will fit under my desk.
* Cool the h/drives, PSUs, maybe NB/GPU, plus any other hot things inside the "case" by actively lowering the air temp using a 350w TEC (as opposed to the fridge's compressor based cooling system). The hot side of the TEC will be added to the CPU water cooling loop- to be passively cooled externally.
* Use the fridge's thermostat & a relay to control the air temp, by switching the peltier on/off. Peltier to be powered by a 3-15v 40A variable switching PSU (already ordered).

Now, the tricky bits-

1) How to cool the air inside the fridge, in a way that removes condensation from the air. My current idea is to create a second water loop from the cold side of the TEC, and use copper pipe soldered to a large, thin, sheet of copper. There would be a drip tray under this, with a hose exiting the case. Because the TEC is only providing case air cooling, and not placed directly on the CPU, condensation should not be a problem as the case cools. The sheet of copper would act as a water vapour condenser, in addition to being an air cooler.

2) I guess I'll need a fan (away from the cold plate so it doesn't disrupt condensation) so that localised over heating doesn't occur during the system warm up/case cool down period. Maybe NB & GPU should be in the CPU water loop to take some of the strain out of this part of the cycle?

3) What will happen as the system re-warms, after shut down? Could circut boards that weren't really warm anyway, now attract condensation as the air temp warms up faster than they do? Opps, hadn't really thought about this...?
Would adding a cold "bank" (ie large block of metal) inside the case to slow air rewarm, help?

All ideas & refinements welcomed.

Shoebox9

[Shoebox9]

PS
In a previous thread LPorc hinted at the concept of hooking the cold side of the TEC to a radiator & blowing air through the radiator & some sort of condensed-water-catching arrangement, to both cool the case air and trap condensing water.

This idea potentially offers faster case cooling, if it could be implemented in a way that was as effective as a cold plate at producing/removing condensation.

[LPorc]

Originally Posted by Shoebox9

PS
In a previous thread LPorc hinted at the concept of hooking the cold side of the TEC to a radiator & blowing air through the radiator & some sort of condensed-water-catching arrangement, to both cool the case air and trap condensing water.

This idea potentially offers faster case cooling, if it could be implemented in a way that was as effective as a cold plate at producing/removing condensation.

Here's my thought from the other thread:

Move the air in the sealed case through a heat exchanger (not a radiator, BTW) where you can catch the condensates (liquids and solids that were formerly vapor before the case gasses were cooled).

I've got a few ghetto ideas for the Air-to-TEC heat exchanger. You could put an existing air heatsink (preferably pinned) on as the cold plate, or you could try going really ghetto by sandwiching some copper tubes between two copper sheets with one of the sheets being the cold plate.

After the air passes the Air-to-TEC hX, run it into a cylinder in a circle. Think kinda like a centrifuge, a bagless vacuum cleaner catch. Take a look at a bagless vacuum cleaner for inspiration. In from the side in a circular are flow, out throught the top center. Let gravity and airflow keep particulates (or condensates) away from the outlet. No bag or filter to possibly accumulate liquids and solids (or worse liquids that will become solids), just a space to catch them and keep the reasonably contained. Your case is sealed, so there shouldn't be a whole lot to catch.

For the truly ghetto effect, I see a coffee can and a dryer air hose for the catch.

And keeping with the ghetto theme, here's a ghetto MS Paint drawing with no explanation:

[Shoebox9]

Great contribution- thanks heaps.

Years ago I worked in marketing for SMC, the world's largest pneumatic products supplier. They sell filters that remove water from compressed air, which work using centrifugal forces (in fact SMC have several design patents in this area).

The potential problem is air velocity v noise. The faster the air is moving, the better this water extraction technique works, but to do this quietly would take a bit of cleverness. Hmm.

[Brians256]

You have a medically compelling need for true silence, and I suspect that there are some alternatives that you might want to consider.

If space is not a concern, and neither is money, you might want to consider something like the Zalman fanless case and just start with that.

If that is too noisy, you might want to build a solid state cooling case that uses powerful TECs (multiple 200W pelts) for cooling. Take a normal case and computer and enclose it in a handbuilt sound deadening enclosure so that only the CD/DVD drive is exposed. Watercool TECs on the CPU and GPU and run the radiator passively outside the second case. Watercool some other pelts that cool the air (using fans to move the air across normal heatsinks on the cool side of the TECs). So, you have fans and noise inside while you have a hot radiator(s) outside. Use radial transmission coolers like the Zalman passive cooler (ebay is cheaper than them). Expensive? Oh yeah. Expensive to run, too, as it will eat power faster than you can believe. But, it will be very quiet.

You could also use the Zalman case a base and TEC cool it's exterior while dumping the heat to some appropriately large radiating surface.

Dunno. I feel for you, bud. Maybe just put your computer in a closet, duct air outside and run cables to a quiet monitor and keyboard? Might be cheaper and still save your sanity.

<edited to remove duplicated stuff>

[Shoebox9]

I was originally going to put my computer outside, in some sort of weather-proof box, and run the cables through the concrete block wall. This would be simplier, but outside temps are a bit wilder than inside.

Spending a bit on this problem, is still cheaper than a career change for me.

While my "ringing in the ears" isn't much worse than a distraction at the moment, I've head of people who killed themselves to escape the constant screaming noise.

[Brians256]

Can you use noise cancellation earphones while working around your computer? Most of the computer noise is steady and should be amenable to algorithm cancellation.

Also, if you think about it, it might be cheaper to put an AC unit in a weather proof box outside than to build some uber-enclosure inside your house.

[Long Haired Git]

I think I've already covered this in another thread, but my solution is to keep things pretty simple.

Inside fridge:
Eheim 1250, CPU & GPU blocks.
Shrouded 120.1 radiator with a 120mm fan hooked as the sole extractor from the PSU.
Ideally laid out so that the PSU's fan draws air over the NB, HDDs etc.
Outside you just need a good sized radiator setup to get or generate as much air flow as possible.

As a guide, I ran an XP1700 @ 1433 Mhz using a old Maze1 and an Eheim 1250 off two 130x150 radiators. They were shrouded (bad) and had fans attached( bad ) but I left them unpowered as passive I ran @ 20 degrees above ambient, which was fine for me.
You'll be adding in GPU heat (30W?) and PSU heat (80W?) and other heat soaked up by the internal radiator (30W?) but then can also avoid my mistakes and run the radiator without a shroud and without fans so that you get as much passive air flow as possible. Hanging the radiator away from the wall and where there may be some air flow (near ventilation, near window) or outside, or under the house, or mounting it horizontally (better) and also just having more SA (so a 240 x 240 or bigger).

If was going to go Peltier (which I'd only do if the above solution didn't work to you satisfaction) then I would do a Cathar-dual-loop config, and tune the Peltier's voltage to avoid condensation by keeping the cold side "cool" rather than "cold".

[Shoebox9]

Brians-

I currenty wear metal housed industiral ear muffs, and I'm sure an active noise cancelling set would be even more effective. On the down side, it's not so helpful when customers come in to plan their wedding album, choose wall enlargements, etc. After 18m of being a secret ear muffs/head phones wearer, rather than ordering something more styish & coming out of the closet, I'd rather just get rid of the things altogether!

Long Haired Git-

I use 1+TB worth of h/drives, so unless I setup these in a gig-lan server from my shed, I probably need some sort of aggresive heat removal from inside any sound reduction box.

Where can I find out more about this mysterious "Cathar-dual-loop config" ?

[Brians256]

Just remember that watercooling isn't magic. You are STILL going to have fans, unless you have some really large area passive radiators. See the Zalman reserator for a mediocre implementation.* Even then, you normally have a fan to exhaust heat from the PSU and other case components.

Also, the pump is not noiseless. The really noise obsessed people on SPCR use pure air cooling. Take a look at the P180 reviews over at SPCR for an example of how they do things with just air. These are people that complain about the noise of their inductors buzzing in the power supply.


* The Zalman reserator is overpriced but not a bad idea. Homebrew alternative is to buy radial finned transmission coolers and use a very quiet pump. It's about 1/3 to 1/2 the price.

[Shoebox9]

Originally Posted by Brians256

Also, the pump is not noiseless. The really noise obsessed people on SPCR use pure air cooling. Take a look at the P180 reviews over at SPCR for an example of how they do things with just air. These are people that complain about the noise of their inductors buzzing in the power supply.
price.

I'm one of those obsessives from SPCR with their P180 cases, but came here after some more advice/ideas on the technical parts of my dramatic (at least for me) plan, listed above.

Since my original post, I've had another thought. I'm going to try and use a temp sensing fan controller hooked up to a relay, to switch the TEC on/off based on water temp. I think this is the answer I've been looking for. This way I'd be able to set a minium/max water temp range, and tame the might beast, that TECs are.

I'll report back when it's all cooking along sweetly (presuming it does!)

Cheers,
Shoebox9

[Long Haired Git]

Originally Posted by Shoebox9

I use 1+TB worth of h/drives, so unless I setup these in a gig-lan server from my shed, I probably need some sort of aggresive heat removal from inside any sound reduction box.

I'd make a custom copper cage for the drives, and just solder a copper pipe on each side.

Originally Posted by Shoebox9

Where can I find out more about this mysterious "Cathar-dual-loop config" ?

OCAU, experiments in Peltiers:
http://forums.overclockers.com.au/sh...d.php?t=141703
http://forums.overclockers.com.au/sh...d.php?t=334206

[jman1310]

why not remote mount the computer?
minimal signal loss at 25' using high quality cords or
up to 500' using cat5e and special off the shelf technology
definately cheaper to make and operate than a bunch of TECs

[laxman]

well lets think about of some numbers (rough and overestmated).

Heat in watts in the case to be removed:
80 to 90 watts from GPU
10 to 30 watts from NB
~120 watts from PSU
>100 from everything else
total: ~340 watts

This means that you will need more then 425 watts case cooling (Tecs are only around 80% effient). Although there is good news about you situation that if you barfridge is truely air tight then it will contain most the sound and will make it alot easier to TEC cool.



What I tried to show (gimp didnt really agree with me) is large heatsink with a tray under is to catch condensation with two fans (top pic). In the lower pic I showed your case, which is huge as I undrstand, with all the unused space filled with insulation. If you do this then you ability to cool the air will be much greater as the tecs will have to cool less air. Also this greatly reduce to almost nil the amount of sound. Finally I would suggest that you use at least 700 watts of TEC cooling power, 3 325 watt ones should be fine.

[Shoebox9]

jman,

My understanding is that DVI monitor signals don't travel well over distance. As I'm editing photos (I'm a photographer) monitor color accuracy is critical.

If there is a way of sending a DVI signal some distance without loss, I'd be very interested.

Cheers,
Shoebox9

PS After some noise testing, I've progressed from my original idea of using the bar fridge as a case, to simply pouring my own concrete case- with all cables & plumbing already in place at pouring stage.

Placing the enclosure open end down, over the computer case onto thin carpet (covering concrete slab floor), should result in a farily air tight, very sound proof enclosure.

This idea makes the shape/size very flexiable, although I may need a car jack to help lift open the case for maintaince.

[Shoebox9]

Wow, 3 325w TECs....?

I'd planned on 2x 15v VMax 350w TECs running at around 8-9v. (I've bought a 40A 3-15v variable PSU for this)

Do PSUs really dump that much heat?
My graphics card is more like 50w, but you've forgotten to add 6x h/drives @ around 12w each = 70-75w

It's a lot to cool..... Maybe I will have to have a dedicated water loop for the CPU afterall, instead of using the TEC's to cool the lot.

Shoebox9

[laxman]

well it sounded like you were going to have a loop with 1 or 2 giant passive radiators. Also on the PSU I was over estmateing, it is probably less then that. So maby a total of around 280-300 watts (I included HD in everything else).

One other idea is dont WC the cpu but air cool it with a huge heatpipe cooler with a high CFM fan. Since the fans will be encased in about 5-6 in of insulation I would be surprised if much noise audible. This would put around 100-120 more watts on the TECS but it takes out the need for two loops. Athough I would worry about the load on the wc that 3 325 watt TEC would put out. This is all your choice though and no matter what it will take some tweaking.

[Shoebox9]

Yes, it seems the trick is to accurately work out the heat load v passive cooling capacity or radiator/s.

I might build the case with two water loops, and just experiment. I'll post the final results!

Thanks all.

[FL3JM]

I think the bar fridge is a good base for making a quiet computer.
If you want to cool the air inside the bar fridge, cant you just make a water loop that connects to the standard cooling of the bar fridge? Just take away the compressor and just leave the tubes that go inside the case (the ones that originally cools the inside of the fridge). You will need two waterloops with this configuration, one that cools cpu, gpu, nb and the pelt, and one that just moves across the cold side of the 350 pelt through the original cooling tubes of the case, through a pump and back.
If you dont want or cant use the original fridge cooling tubes you can allways use a rad with a fan. That way the radiator will cool the air pretty efficiently. Ofcourse you CAN run the cooling radiator passively inside the case, but then condensation will build up.
I really dont know how much condensation can build up on a sub ambient cooled rad when the case is enclosed air tight. It all depends on the humidity and volume of the fridge, but even at 100% humidity 30 litres of air wont make alot of water i think. And if condensation is a problem you can allways put in silica gel or whatever inside the case that draws the moisture out of the air. That way you will never get condensation what so ever cause there is simply no water in the air that can condensate.

You will have to get a really big rad outside the case that can handle the generated heat, but that isnt a really big problem i guess (just get a big car rad and place it outside your window or something ghettoish )

Interesting project, it redefines the meaning of a really quiet computer.

[BillA]

remote the box, solve your display issue

[Shoebox9]

Thanks everyone for your input.

FL3JM, simply replicating the fridge's cooling system was my aim- with the cold side of the TEC's mounted onto a sheet of copper, as a passive air cooler. This way it deliberately creates condensation, which is either collected in a drip tray, or freezes on a safe spot- either way if is removed from the small packet of cold air.


UPDATE- due to employing a new staff member I need to move my office to another room, and by good fortune the new room has a cement brick internal wall dividing off a washroom, which already has a built-in cupboard, in just the right spot! I now plan to take the easy way out and simply put every cable I might ever use through that wall, and then bog it back up again.

PLAN 2-

Bolt one of those groovy Swiftech MCW-CHILL 452™ dual 226w TEC water chillers to the cupboard door, with an MCP350 for the cold side, and another for the hot sides. Next- cut a 120x3 hole across the bottom of the cupboard door, and another across the top of the computer’s internal cupboard division. Place 120.3 rad with fans blowing chilled-on-the-way-through air in at the bottom, and a 120.3 rad at the top blowing out, which also cools the TEC hot side water loop.

I figure this would be around the same cost as an internal free standing air-conditioner, run more quietly, chill my “server room”, and give me something to do with my variable 3-15v PSU, & mCubed T-Balancer. (The wife gets cranky if I buy stuff but don’t use it!)

Thanks again everyone. :-)

Shoebox9

PS I believe my original idea really has potential, and would greatly reduce condesation problems for O/C'ers using extreme cooling. Put the PC in a freezer with the phase change unit running externally. Pre-chill the air with the PC off, the water in the air freezes on the freezer plate, then go nuts. As long as you don't open the freezer door till it's all warmed up again- condensation problems solved.