[Diggrr]

I know I said I'd have this up yesterday...RL sucks some days!

First order of business is to get a copper loop buried in the ground to use as a radiator. This saves listening to fans, and the side benefit is that the in-ground temps are much cooler and more stable than anything using air cooled radiators.

I chose to do my underground loop in 3/8" OD copper tubing, the soft, bendable, thin walled tubing from Home Depot.
A funny thing about economics, they had 20' sections for $15, and a 50' section for $49...yep, two 20' sections it is...why pay $2 per foot for that last 10'?
To fasten the two sections together, I chose brass compression fittings, though on the copper side they are also soldered to the tube just for peace of mind and lack of needing to dig it up should it leak.
To bring the lines into the house I chose polyproylene tubing, that milky white and rather rigid stuff. I chose that because it's mighty difficult to crush should the ground settle on it. I also didn't want copper in my riser tubing to help avoid freezing better.

Now to dig a trench. Once coiled, my tubing measures 16' long, and giving 2' extra for bend radius on the poly tubing as well room to bring up the riser next to the foundation, that left me needing an 18' long trench, 36" deep to avoid Michigan winters (and hopefully anti-freeze).



The tubing was coiled around a 5" former of rolled aluminum flashing that was handy, and it's rigidity made it easy to coil the copper loosely around it with 8" between coils.
Shown in the pic, the return of copper was blue taped to the coils, but that was just for carrying. The tape was removed and the lines spread a bit apart before burial...don't want heat to transfer from the warm to cool sides.



To bury copper tubing in a coil like that, you MUST wash the dirt back into the hole. You don't want air in the soil to hinder temp transfer, and you don't want the ground to settle later on and possibly crush/crimp your tube.
I raked it into the hole 3" at a time while removing stones, soaked it with the garden hose, then raked in some more. I made a thorough amount of mud that took days to settle out in my heavy clay soil.

For the riser, I went to a bit of extremes to avoid the possibility of freezing. I'd rather not use anti-freeze in my loop if it can be avoided.
Each poly tube has a 1" piece of grey plastic conduit around it for air gap. I then slipped on a piece of 4" PVC tubing and filled the space between the conduit and the PVC with great stuff foam insulation up to the top. To fill a long section like that, I started with a piece of aquarium tubing attached to the can to get the foam to fill from the bottom upward, and pulled it out as it was filled. Perfect fill.
Once that was hardened, I added the 90° elbow to the top, and filled that too with spray foam.
I trimmed away a square of siding from my house and mounted a 3/4" plate to the wall, already primed and painted to match the PVC (which is also primed and painted to avoid UV exposure/harm). That plate has a recess routed in to slip-fit the PVC elbow, and has two holes to match the poly tubing.
The pic shows it mounted and caulked nicely to prevent weather intrusion.



Once through the wall, I fitted a drain fitting to the return side, and routed the tubing up the wall in a track I'd made. This keeps the tubing neat and prevents snagging, as this is an HTPC and I work around the area a lot.



Now for the reservoir. Starting with an OXO food storage container, I glued a plexi plate into the bottom, and drilled/tapped it to accept G1/4 fittings.



That sits atop of a box I made, that houses the pump, a cooling fan, and my trusty old Coolermaster AerogateII.



You can see I modified the pumps, cutting out air holes in the bottom of the pump housings leaving an "X" shape and the center ring, then I added 1/8" holes around all 4 sides of each pump to let 'em breathe.
One pump is my old MCP350, the other is an MCP355, both acquired from forum members here.
The dual top is fed by a 1/2" Norprene tube from the res' bottom fitting, everthing else is 1/4" ID.



I paired up the pumps because of the footage I have of rather small lines, and the whole system including my DTek Fusion V2 waterblock maintains 1 Gallon+1 Liter of flow per minute.

Finished!



Temps stick to 14.5-15°C for the water, and my CPU is 21°C Idle, 25°C fully loaded.
I'd call that a success!

Questions or Comments are welcome.
Thanks for stopping in a peaking.

[dtrunk]

+like9billion!

can you it a full load for like 3-1/2 weeks and see if you break 30c?

PS: Moar pics!

[pwnmachine]

Wow that is simply amazing, I have never seen anything like it!

[NtheFace]

Kudos... simply amazing engineering on that...

Even if for some reason that failed, which it DIDNT A+++ for effort...

[Conumdrum]

Can't wait for temprsults and long term usage results.

This is called 'green cooling' and nicely done!

[Diggrr]

I'd been running it all week gutted on the floor and using an ice cream bucket as a reservoir while I finished the real res, and the temps posted are it!
At start up it's room temp, and drops to 14.5 within a minute. After about 5 hours it gradually "climbs" to 15. I've seen it hit 15.5 once while running Prime, but after an hour water temp went back to 15 and stayed there over night.
The tube that goes through the box from the underground loop to the waterblock has a 4" piece of copper tubing joining the two types of tubing, and on that is my temp probe fastened with furon temp conducting tape--the same tape the probes come wrapped in.
The system is res>pump>underground>CPU>back to res, so that's the temp from the ground.

I'm thinking of picking up a can of flat black BBQ paint to paint the drain fitting, so I can use an IR thermometer for a second opinion though...it's very thermally conductive paint, and the IR's are best on non shiny surfaces.



It says CPU, but I don't have a 7' probe to reach the CPU, the Aerogate complains when there's no probe or fan on the CPU channel, so I had to use one. Normally I don't care much about the water temp, but this is a bit of a special case I guess. The RPM is the 355. I plugged in both pumps and the fan to the controller so I get an alarm when something quits.

[GTXJackBauer]

I mean amazing. If I was you I'd patent this idea as you never know some futuristic homes full of eletronics could use some good cooling. Just saying and I said it so I'd only ask for a single digit percentage once this went global. AMAZING. I kept going back to your old thread looking for updates till I found this new one. Great job. Innovation starts here......

P.S. - The housing that was laying on the floor without reading originally I thought that was a safebox I'am like oh this guys making it fire proof! WHOA! haha

[Atomichearse]

This is the coolest thing ever! (no pun intended)
That's such a great idea. It's even better that it works!

[Diggrr]

Oh I'm not the first to do this, I just tried to do it better though.
I used the soft tubing for better heat transfer with the thin walls, and it's coiled so that the water is forced against at least one side for "impingement"-scrubbing off the boundary layer of water molecules that don't move much.

Hopefully this will be enough for my meager video card to be added without too much penalty...it not, I'll be digging again!

**Lolz at the fire safe! It's top back and bottom are 3/4" Pine board, the front and two sides are 1/4" HDF (aka malamine, like a clipboard). I used Rustoleum Hammered brown paint, the flash makes it look lighter than in person. The black lining is a dense neoprene foam with an adhesive peel and stick back--I used to work at the company that makes it, and have a few yards of it.

[Seebs]

I wish I could do something like that, but here in SoFla; I'm afraid that I'd just be warming the water up instead...

I'm sure that loop would be able to handle waaaay more than what you're throwing at it right now.

[Diggrr]

Yeah, it's only a 65W processor, and the video card is a passively cooled GT520 (with a monster heatsink that I'd like to get rid of). This mobo only allows .15 increase in volts, so that won't be changing as I try to OC higher.
I'll be finding out next week, no one makes a GT520 block, so I'll have to make one of my own I guess. None of the universal's have a 3 bolt pattern.

At least in Flordidia you have sand so the digging is easy! Go down 5 feet! The downside is you have to dig 10' wide to go 5' down!!

[Convicted1]

Awesome Thread and awesome project!

And yep... Dig Deep Enough... You'll eventually get to 55 degree dirt.

[Diggrr]

Thanks!

Let's see...a couple buddies with 12 packs, 2 ladders, a gas-powered post hole digger w/5 extensions. Go vertical!
"Hold my beer and watch me get a Darwin award!!"

[mjw21a]

This is easily the coolest thing I've ever seen on here. I imagine your computer would be just about completely silent now. Awesome, I suspect it could handle a pretty decent overclock too

[bluezero5]

Amazing !!!!!!!
thanks for teaching me something new today!!

[Seebs]

One thing I was meaning to ask... I see you only went with 36" of depth for the trench; are you sure that depth is going to be below your frost depth?
I remember seeing another geothermal loop over at XS and the guy mentioned he had to go 60" down in order to avoid the winter frost from damaging the pipes and/or freezing the water.

[Convicted1]

That was my first thought as well being in MI...

Here in Missouri... The freeze line is 18-24".... I'd think it'd be quite a bit deeper up there.

EDIT...



Looks like you're good to go @ 36".

[hafa]

Originally Posted by Diggrr

At least in Flordidia you have sand so the digging is easy! Go down 5 feet! The downside is you have to dig 10' wide to go 5' down!!

Another thing to consider is that ground temperature is a function of the average air temperature in a given region. That's why deep caves in Southern Idaho have temperatures around 0-5C, while deep caves here in the Marianas have temperatures of 27C. Ground loops are well-suited to Northern climes, but provide no benefit in the tropics.

[Diggrr]

Yep, I live across the lake from Chicago, in the 28" zone, although that's a worst case scenario even then.
You can bet I'll be watching temps, maybe adding a bit of AF through the first winter just to be prepared...I didn't forget the drain, so it won't be hard to flush it back out.

Still, adding anti-freeze isn't as huge a penalty as we make it out to be. Maybe 3-5°, which I can easily afford starting this low to begin with.
Plus the frost line is just that, the zone where it begins to freeze. I would only need protection to maybe a few below to be safe, certainly not a 50/50 mix like in a car (-40°F).

**If all else fails, it's only $30 worth of copper. I can retrench it to 48" if I don't like the results.

[mjw21a]

Originally Posted by hafa

Another thing to consider is that ground temperature is a function of the average air temperature in a given region. That's why deep caves in Southern Idaho have temperatures around 0-5C, while deep caves here in the Marianas have temperatures of 27C. Ground loops are well-suited in Northern climes, but provide no benefit in the tropics.

Bugger..... Looks like there's little chance of running one here in Australia..... Might be ok for those in Tasmania and Victoria still though.