ground temperature exploitation

the gournd stays around 56 or so degrees fariegnhieght year round at depths of 2 or so feet around here, in oregon.

So, I wonder if burying copper pipe aout 1.5 feet down in a winding pattern, would give good temperatures, siliently...

r, would a multiple-channel parrallel setup be better?

Also, in a one pump setup, what pump should I use?

in a two pump, I plan to use my Eheim, and also to use a very powerful one to push water through the pipes, which then will be pumped into a resivore.

I don't know what temps are like there in the winter, but here it gets down right cold. The frost line here alone is two feet so I would go deeper to get a constant temp throught out the year. You could use an antifreeze to keep it from freezing, but that won't eliminate the temp fluctuation from season to season. From what you stated about it being 56°F two feet down year round you must be close to the coast.

you would want to bury it at least 4 feet deep, You can keep more stable temperatures year round, Im sure it changes daily at that depth, You would want multiple grids so you would have more slower flow thru them.

Nick, even if you deploy a long run of tubing with no appreciable vertical lift, you will encounter resistance to water flow as a function of the friction between the water and the tubing inner wall, so plan on a hefty pump. That issue notwistanding, a buried tubing setup will work well. Also, consider the impact of being tethered to a tubing network with regards to mobility of the system.

Hoot

I saw a big article where a guy did this going for silent cooling. He had blocks on everything including PSU. His res was buried about 8' down. He used an large oxygen or acetylene tank from a torch setup. Ill try and dig up a link for ya.

peace.
unloaded

you mean bladerunner?

Yep that's my set-up detailed at Zero Fan Zone.

I wasn't however the first to do it. Burgerman had beaten me to it, although I didn't know of his project until I'd posted details in a forum about mine, and then someone linked me to it. Unfortunately I can't find the site he had up about it all now, and he makes no mention of it on his new site, HERE, not sure why??

Anyway I've been using the system for a year now and here is a recent bit I wrote about the underground tank, and my findings living with it so far:-


"On the underground tank cooling there are a few things I've learned after living with the set-up for a year.

For it to work efficiently the tank will need to be fully immersed in the ground water. How deep this is will depend on your specific location, but when the hole you've dug fills with water, that's the ground water level. It can change from winter to summer so it's best to find it when it's at the lowest point, generally in the summer after a longish dry spell. If enough coolant is used, then it will work without being immersed in the ground water but not as effectively, and will tend to slowly heat up. My current 100-litre propane tank 8-foot underground only has the bottom foot or so immersed and it does slowly heat up. I don't run my PC 24/7 so it's not a major issue. But it needs to be appreciated we are only talking maybe 3°c to 4°c rise in a 12 hour period of full load PC use, today for instance my PC has been on for almost 10 hours and the temp on start up was 12.8°C and has risen 2.5°C since this morning. When off for a period the underground temperature returns the coolant to whatever the underground temp is. This in use temp rise would not continue until the coolant boiled of course, as there would be a stabilisation point. I have never run it long enough to find this point as I don't like leaving the PC on when I'm sleeping, but my guess is it would never get to a temp as high as a "normal air-cooled rad water-cooling system" starts out at. What it possibly would not cope with is a high watt TEC especially run for long periods. I will be making a second underground cooler build sometime, as I'd like to see if it can be improved with copper coils immersed under the water table to cope with high watt TEC use.

One last point is the assumption a mega powerful pump is required for this type of set-up. The way I have it set-up with a header tank / reservoir above PC level is exactly the same principal as a UK domestic household central heating system. Just as in the central heating system there is no pressure pumping, just circulation, and central heating systems cope with a two or three story house using a normal low-pressure circulation pump. Circulation is something aquarium pumps do well. I'm using an Eheim 1060 that gives me good flow rate through all the blocks in my system, although it's a bigger pump than would normally be required in a "standard water-cooling system" this is really only due to the extra distance / tubing the coolant has to be circulated around going to & from the tank. The header tank also makes system bleeding a non-issue."

Those that don't know what I'm on about read HERE (and go to the "bomb" page).
This basic schematic should explain it briefly

i'd thought about this as well, maybe just burying a large tank or a very large radiator about 4 feet underground, ground temps below 2 or 3 feet here maintain a constant temp year round, if it's necessary to have the tank/rad immersed in ground water, it would simply be impossible in the mtns where i live. well, possible but extrememely expensive, as most folks have to drill to 75-200 feet to hit ground water. nice eh? so maybe you could get acceptable results from a rad or something buried below frostline....

I'd been thinking all summer about doing the geothermal cooling too. My idea is to rent a 6" post-hole digger and all the extensions they can get their hands on. Then when the hole is dug/drilled, just place a U shaped 1/2" copper pipe down it into the water table and backfill using the garden hose to pack it all back into the hole.
That's about $7 every 10 feet of copper (dual pieces) according to Lowe's prices....not too bad. Maybe even use PEX tubing they sell for in-floor heat exchange systems. Or yet another idea was to make a 20 foot tall loop, and use vinyl tubing to make up the height to the ground level.

Anyway, the idea was to drill to a depth well within the water table and see how that would disipate heat without the large tank's surface area. I also wouldn't have to explain to the Mrs. about the pit in the front yard..

w00t thats the setup, I wasn't sure until i saw the backhoe pics again. nice setup, although i thought the psu was watercooled too, i didnt see it on the links.

juliendogg

the water-table and underground rivers (where you'd drill a bore hole for a well) are different things. True if you are in the mountains then I'm not sure where the water-table would be. It also depends a lot on your location and how wet or dry it is. I'm fortunately (or unfortunately depending on how you look at it), UK based and it is a very wet place we have widespread flooding atm in some parts of the country.

It needs to be appreciated that soil, dry soil especially is a very good insulator, (they used to make walls of houses out of it), so won't be very good at heat transfer. If it's damp or wet it will be much better. It may work but reread my last post with regard to the fact I have a 100 litre tank 8 feet down (bottom foot or so in the ground water and it still warms up in use (all be it slowly).




Diggrr

That could work but make sure any connections that will be buried are very secure. I'd back fill with a smooth gravel up to the water-table depth as it would allow more water to tube contact, but this will cost a little to buy. another thing to take into account is the possibility of the pipe being squashed as you back fill.

The tank I used is not the most efficient way to do it as the surface area to coolant ratio is poor. It was just the simplest solution that presented it's self to me at the time.


UnLoadeD

The PSU build is detailed on zerofanzone and there is a image link on the main page.

The later updates are not included yet, which are a bracket from the block to help cool a coil that was getting too hot for my liking some general thinning out of the plug wiring and cut-outs in the PSU case to help the natural heat rise airflow.





One last thing to consider is any coolant or water that you run through your systems tubes or blocks that's colder than the case ambient could cause condensation to start to form, related to the relative humidity

well, i guess there's alot more too it than I htought! I thoght I'd just entertain the idea to see what it would take... maybe I'll do it this summer or something

-nick

wow thats amazing,

i think im not too far from the watertable cos i live here in the uk and i remember digging a hole for the pond a few dry summers back, we got down to about 3-4ft and the soil was quite damp.

im going for silent pc too but i think w/cing my psu is a little complicated, i think i could handle the mosfets but does the coil thing in the middle have to be cooled too? will it be ok passively cooled?

There ws an article on this in the water section of the frontpage if I remmber, I don't remember which one it was <g>

-Toysrme

I'm not trying to put anyone off the ground cooling as it is a very effective way to get to fanless water-cooling, (assuming moving the PC around is not a requirement). I just wanted to share my thoughts / findings after living with it for a year, along with thoughts of what I could have done better.

At the end of the day I'd like to make a water cooling system that will cope cooling at least two top end PC's without getting warmed up, one of which will have a few Tec's and Tec PSU, and everything being water-cooled for total silence. I have a bore well for my domestic water supply, It's basically an 8 inch id metal tube that goes down 180 feet into the underground river. The water coming out of this is around 5c to 7c most of the year and I hope to run a copper coil down into this well. I'm currently building a house, (hence the digger), so due to distance it's not practical until I move into the house.

A Copper coil should work better than the tank, however it's working out how much coil I'd need for it to counter any possible warming up of the coolant with a high heat load using TEC's



seal

PSU's differ so much so I can't say when water-cooling. What may work on one might not on another. At the end of the day they are designed to have airflow from a fan or fans, so if you remove this it can have many undesired effects.

The trouble with all the fanless psu's I've come across is they aren't rated to run at or even near their max loading fanless, the TK power one for instance can only do less than half it's rated wattage without a fan, and will still probably get hot. Until they start designing PC psu's to be fanless from the outset, it will be difficult to run a top end system with zero fans in the PSU, unless you successfully water-cool it. As far as non water cooled fanless units go this is probably the only one I've seen that might cope, but I have no experience of the unit myself. The whole PSU is a heatsink so I guess it still will get pretty warm if not hot.