The Hole…Geothermal Loop…56K Warning!

[Naja002]

Months back, I was getting bored and looking for a project…a PC cooling type of project. I started seriously looking at putting copper pipe in a crawlspace and a number of other things. I ended up going with this seasonal dual car rad setup:

Yes, Another Car Radiator Thread....Major 56K Warning!

I ended up getting into “crunching” (Distributed computing) Boinc/WCG, F@H, GpuGrid, etc. Now I run 4 OCed rigs and 4 OCed Gpus 24/7. The entire setup sucks about 1,200-1,300 watts out of the wall. During the summer the heat is ridiculous—even with pumping a lot of the heat outside. It got bad enough that I purchased an 8K btu a/c right before the weather turned cold. Needless to say, my electric bill sky-rocketed. But now that system is providing my winter heat via the indoor rad…...I have not turned my heater on so far this year (temps as low as 30F/-1C with highs in the 50’s-60’s, but as low as the 40’s). The ONLY supplemental heat comes from a 1K watt $20 space heater from wally-world. When temps outside start dipping into the 30’s it’s in the low 70’s in here ( ~72F with 30-35F outside). Additionally, I don’t run it everyday and only run it a few hours through the coldest part of the night…some nights. Not much at all.

So, what does any of that have to do with “The Hole” ? Honestly, it’s just a little background to help you understand what’s going on here and how the goals have come about…..With the way the economy is and has been, things have reached a point where I would have to choose: Suffer, shutdown the PCs or do without heat. Now I don’t have to choose. My electric bill last summer kept climbing and climbing and climbing. With this seasonal car rad setup, my electric bill (after doing the math) decreased ~$40. That’s with a 20% rate increase. Its winter folks—everyone’s bills are going up. Mine went down! And its going to go down further. With this Geothermal Loop I expect to not have to choose this coming summer, and with the way things are looking atm….I’m not going to have to choose!


So, on with the show:

This is what I did, how I did it, why I did and what I would change—Yes, If I had it to do over….I would probably do it a bit differently:

First I had to decide what kind of pipe to use for the exchanger and why: PVC, HD polyethelyne, copper, etc. Then what size for maximum surface area v. cost and all that good stuff. Ultimately, I went with 3/8” copper refrigeration coils…50’ x 4 = 200’ total. And that is one part that I might change, if I had it to do over:






My original intent was to dig up an old plant bed, dig deeper and install it into there. But after thinking for a while, I came up with a number of reasons why I really didn’t want to do that. So, I sorted out a new location and started the hole from scratch:



8’ x 5’

Then the Real work began….sheesh, what a job:





By the end of the first day I reached ~22” depth. Now keep in mind that this is clay and got harder and harder the further down I went. Some of it was like trying to dig through concrete:

[Naja002]

So, bright and early the next morning, once again all wired-up on caffeine, I went back to work. I dug out about 25% of the next layer and decided to check something out. At ~22” depth I drove the shovel in, cracked the ground and inserted a temp probe….this is what I found:



Then at ~28” depth I did the same thing:



The increase in ground temp directly indicated to me that I may have reached temp stability. The frost line here is only 12-18” (less then 18”). Ground temp stability is reached shortly below the frost line….so, this makes sense.

Finally, after digging the hole I checked once again and several inches deeper….the temp was the same:



Understand that when I did these “tests” I just cracked the ground, inserted the probe as deeply as possible and got everything closed back up. Then waited for the temp to stabilize.

These tests indicate to me that I reached ground temp stability…at least for this time of year. Through out the winter this spot is shaded 24 hrs/day. In the summer it will get a few hours of sun, but not much. That’s one of the reasons that I chose this particular spot. As long as the temps don’t exceed ~68F….I expect to have almost free air-conditioning!!

So, by the time I got done digging the hole….this is what I had:





In the top left corner of the 1st pic above you can see where I dug out for the pass-thru into the crawlspace. That pass-thru is ~12” deep.



Just a pic of the final ground temp test and digging the pass-thru:





I had decided to put copper in the ground, but make the “run” with pvc. Part of the rationale of this was cost and part was thermal conductivity. Copper = ~401, PVC = ~0.19. I could have gotten picky about making the run to the hole out of copper (warmest water) and all that, but I decided to keep it simple, so I made everything out of pvc, except the heat exchanger in the ground (copper). Anyway, the hole and pass-thru where done, so now it was time to start the plumbing. Initially, I was going to do this a bit differently, but, ultimately, decided on what’s pictured below:

[Naja002]

As I’ve said in other posts….I like to build plumbing from opposite ends and from the middle to the ends….meet in the middle so-to-speak. Crazy? I don’t know, but that’s how I do it! So, I started at the pass-thru, but the first thing that I did was install a temp probe. I picked up this indoor/outdoor thermometer for ~$9 at lowes:



It has a 3m (10’) “outdoor” temp probe on it…..so, I threaded that through some ½” pvc as follows:



Got out the construction adhesive/caulk:



Pulled off the sticky paper and stuck it to the inside of the pipe:



Then filled the opening with caulk:



Glued the cap on (all of the pvc was glued together):



And let it sit for a bit:




Then covered it up:



I dug out an extra 2-3” at that spot in order to insert the temp probe. Heat rises. I want the temp of the ground…not necessarily “the pit”. Plus the end where it is buried is the cool end return. Hopefully it will work out as planned….it should, but we will see this summer.

After sitting buried for a bit this is the result:

[Naja002]

So, on with the rest of the plumbing. Again, starting in the middle. 1 ¼” pvc pipe was chosen for reduced frictional loss:









At this point I had pretty much decided to call it a day. But I had too much to do in too little time, so I went a bit further.

I decided to take the pit plumbing to the manifold start:






Took a soil sample in order to determine the soil’s pH. Got it setup for later testing:

Distilled water….









The liquid test bottomed out at 6.0 (as low as it goes). The Ph controller/probe settled at 5.9, so the soil is acidic. In order to help balance that out I picked up some Lime from lowes:



I put 2 cups at 1lb 11.5 oz each on the bottom of the hole:





I covered that with about 1” of soil to help prevent direct contact with the copper tubing:

[Naja002]

Finally, after deciding what size tubing, how much, etc….I had decided before even starting this hole that I would run 8 parallel loops = 8x 25’, so I had to measure out and cut the 4 coils in half:



So, now it was time to call it a day.

So, now on day 3 things were getting rough—really rough. Pumping caffeine and popping max strength Tylenols (heavy duty drugs here, folks ) it was tough to get started. But I knew that I needed to get this done and the hole filled back in. I had today and tomorrow to reach that point.

I picked up a container at wally-world to house the indoor/outdoor thermometer. Cut a small gap for the probe wire:







And stuffed this up in a spot that’s +12” above the ground. As a note: the ½” pvc also rises +12” above the ground.


Now, I realized before starting the hole that I would have to build the manifolds on site (in the ground). It would have been really nice to do it sitting in a chair, but that wasn’t going to be possible. The problem was the heat from sweating the copper and the copper’s connection to the pvc. So, prior to digging I sweated together the initial copper to 3/8” connections….all 16 of them:




So, I then sweated those onto each end of the 8 25’ coils, then sat down and applied Teflon tape to all, a 1 ¼” tee to 14 and an elbow to 2. Determined my pipe length for in between the fittings and cut 16 pieces of pipe. Glued those into one end of each and things were setup to be completed in the ground.

So, after setting everything up….it was time to get back into the hole and start putting things together. Ultimately, it ended up looking like this:







Now, for those who are going to say” Oh, man, you shoulda done this instead of that or that instead of this”….as I said at the beginning of this thread: If I had it to do over there are somethings that I might do differently. Don’t get me wrong…I am open to comments and criticism…there’s no problem there. But it is done the way that it’s done and initial results are very promising!

The hole actually has a grade. The sloping pvc is the input (warm water), the elbow straight up is the output (cool water). The grade slopes downward from the input ~29” to the output ~32-33”. The purpose for this is simply that heat rises. It’s a simple effort to help keep the warmer ground from affecting the cool water result. Also the tubing coils rise 3-4” above the ground…they are not in direct contact with each other as it may appear in the picture. When I filled the hole back in…I made an effort to make sure that I did not compress the coils onto each other. In other words, there is earth separating the coil loops. Yes, there is some contact, but not near as much as may be assumed from the pictures.

[Naja002]

So, after getting everything laid out, and with the repeated insistence of my Buddy Hicks ( Thanx, Bro!) it was time to leak test. I wasn’t going to, but I did. Running out of time I decided to hook up a garden hose, fill the system and then use it for the leak test:



Well, I had a leak. One of the 1 ¼” x ½” tees had cracked at the neck. I had this issue before on my seasonal manifold and fixed it like this (pix borrowed from that project):

Put gobs of pvc glue on/into the crack and squeeze it together with a clamp:







Again, those pix are from that project. Same issue, same fix….just more glue used on this problem.

So, after letting it sit for about an hour I decided to try the leak test again. The leak was down to a drip, no other leaks noticed and I knew it would be a few hours before the one leak completely sealed itself. So, still running out of time…I decided to move forward. I put a couple of inches of ground on top of the coils/pvc and then added another +3lbs of lime. Then kept filling in the hole. All-n-all I used probably 15-20lbs of lime adding some every 6” or so. I ran water the entire time to help the clay settle in and fill the gaps. I soaked everything down very well. I managed to get the hole ~50-60% filled and it was once again time to call it a day.

Day 4 was fairly simple. Finish filling in the hole, replacing the sod, spreading seed and just getting everything situated to where it didn’t look like I dug a hole (as much as possible anyway) and get everything shut down for a few days.

The Hole:



The Pile:



As day 4 went on I continued to try to fill/leak test everything. From what I could tell I still had a leak. Seemed to be about 111 oz/hour…just under a gallon an hour with only gravitational pressure. Hmmmm, not good, but 24 gals a day was something that I could live with and build a work around if I had to….but I’d rather not have a leak. Hmmmmm…..

So, everything was shut down in preparation for a few days at work. I managed to sort out what was needed in order to now complete the run inside to finish connecting everything into a working system. Stopped by lowes and got what I needed.

[Naja002]

After spending my days at work I was now once again free to do as I please, so Day 5 consisted of fixing the leak and just generally checking things out. Now I know that Black pepper can be used to temporarily fix a small leak in a radiator. And I also know that digging the frickin’ hole back out is not an option for me. So, black pepper it is!!! I set everything up in order run the system with an extra pump that I have. Amazingly that pump is only rated for 6’ of head, but did the job very well. I added the black pepper to the system and got everything going. The black pepper did the trick!!! Yes!! So, I let the system run overnight. After checking things out on Day 6 it was now time to get it together and get this baby hooked up and operational….so that is what I did.

I plan on plumbing another rad into the living room, but I want to be able to isolate the system to just this room, if necessary. So, that should explain the tees and ball valves:



I added unions on each run of pipe for drainage and future disassembly:



Each pipe runs at an upward angle to the elbows where is goes through the floor:



While I was out there taking pix I checked the temp probe:



I had remembered that I had forgotten to reset the min/max after I got done filling up the hole, so I went a head and did that for future reference. If it matters, they read min: 52.?, max: 55.0…..they had not changed since filling up the hole, so that’s good.

Not as neat as the car rad setup but this is the geo-loop coming through the floor:



I may redo it some time in the future, but it will do for now at least. The gate valve on the left is the output from the hole (coming out of the hole and into the pump, rad, etc. Cool water). The elbowed one on the right is the input into the hole (warm water). I need to fix the upper connection to the seasonal manifold…I have an elbow. I may use that or fix it some other way. Right now it doesn’t seem to be having any negative effect on flow—with or w/o the geo-loop going.

A pic of the geo-loop setup with the Eheim 1262 pump:



Just a pic of the indoor rad setup:

[Naja002]

Here are 3 x 3min videos showing the Geo-loop effect. Keep in mind that this is after 3 minutes the temps drop another degree or 2 after a while longer. More importantly, this is with the OCed crunchers pumping heat into the system. Without the crunchers it will drop another +7F.

Video of the air temp coming out of the rad fan. The clay covered probe is inserted in the fan in the background of the video. Audio has NO value:




Video 2 is the water temp entering the water block on the vid card of cruncher #1…it is pre-warmed by an OCed NB. The water temp is the blue LCD:




The last vid is basically a video screenshot showing the cpu temp change of Cruncher #1 which is a Q9450 @ 3.584. Please keep in mind that the cpu water is being pre-warmed by an OCed NB and an OCed Gpu:



Also Please keep in mind with the water and cpu temps--this is not the only rig on this system....

[Naja002]

Ok, so my basic plan at the moment is this: I will continue to experiment and play with this setup over the winter. However, without a heat pump it really defeats my purpose of using my PCs to heat this place. When the warmer months arrive I will be able to experiment futher. I plan on using this Geothermal setup for A/C type cooling….not PC cooling. I plan to add another car rad which will be located in the living room. I also plan on adding another car rad outside. The Dual outside rad system will be the PC cooling system, and the Geothermal loop will be the home cooling system. If it is insuffucuent to cool this place then I will have to determine whether to let it supplement the a/c or confine it to this room (this is where the PCs are). Either way, this will save me money this coming summer. The Eheim 1262 is an 80w pump. The push/pull car rad fans are running @ 5v and pulling 43w. 1 9” fan on high=45w which will more then adequately mix the air in this room. So, basically I am looking at 168w=$12.18/month. If it is sufficient to cool this whole place then 43w more will be added and 2 9” fans that are already running (on low)….for a total of 133w +168w= 301w= $21.81/month for cooling…A/C!! Either way, this system will pay for itself in no time.

Cost:

Copper tubing--$231
Pvc, Copper fittings, etc--$296.15

Now I have probably $30-$50 worth of returnable stuff. What I am going to return and why….I don’t know at the moment. Also, the $296 figure includes a set of pipe cutters, Teflon tape, etc….Its an all inclusive figure, so $250 is probably more accurate. However, it doesn’t include a few thing that I already had like some of the 1” barbs, blue tubing, etc. So, we’ll go with the $296 figure….if it’s a bit high that’s ok.

So, my guesstimate is $527.15 out-of-pocket.

Also, that doesn’t include the car rad $68, pump $109, fittings for that stuff, etc. I already had that stuff in use….but there’s the general value.

I hope Ya’ll enjoyed the show…still need to wrap the pipe with insulation and then cover with foam, so there will be more to come. Anybody looking to save money and go green—look into Geothermal…just google it. Nothing new. Been around for many years….pays for itself in 3-5yrs on average with a professional install. Check it out….


Oh, did I tell ya the part about how much I hate anything that involves a shovel…..

[teyber]

jesus, not much to say other then Awsome!

[xsbb]

OMG.. I'm impressed with your work!

AMAZING PROJECT!

[[XC] Hicks121]

Well done brother!!

How's the back feeling?

This will be great at the cottage.

[eligray]

WOW! Great setup! I'd definately use a high-flow pump on that if i were you, especially since you have so much dissipation. With all that dissipation, peltiers become a lot more viable. Did you use fine, powdered pepper to patch up your leak? Everything about this project was great. When you said at the top that you might have changed how much pipe you used, what specifically did you mean? Very nice!

[orclev]

You are a sick sick man, but in a good way. That's a seriously awesome setup. So yeah, now that we've seen your awesome work, what lessons did you learn from it, and what would you do different the second time?

[Unseen]

crazy people...

[Quad-Damage]

how loud is that setup

[Plan.B]

wow. impressive - from concept to execution. I'd rate that as xtreme. good job!

[Naja002]

Originally Posted by teyber

jesus, not much to say other then Awsome!

Thanx!

Originally Posted by xsbb

OMG.. I'm impressed with your work!

AMAZING PROJECT!

Already looks like money well spent!

Originally Posted by [XC] Hicks121

Well done brother!!

How's the back feeling?

This will be great at the cottage.

Bro, You won't regret it. Set it up at the cottage and the Mrs. will be begging you to set it up at home.

Originally Posted by eligray

WOW! Great setup! I'd definately use a high-flow pump on that if i were you, especially since you have so much dissipation. With all that dissipation, peltiers become a lot more viable. Did you use fine, powdered pepper to patch up your leak? Everything about this project was great. When you said at the top that you might have changed how much pipe you used, what specifically did you mean? Very nice!

Thanx! The pump that I have on it now is an Eheim 1262, 80w, 11' 6" of head and 900gph. Its definitely strong enough for the job, but I may check it out with an Eheim 1250. The temporary pump that I used was a low end: ViaAqua 1800---6' head, 480gph, 28w. They are great little pumps for what I used them for, but I don't really trust them to hold up in this kind of application, but it did fine for the testing.

From what I've read 3gpM (180gpH) is the minimum in order to create "turbulant flow". Now I assume that's within the standard 1" pipe (usually HDPE). If so, then I am also willing to assume that it would take a bit less in the 3/8"OD pipe that I'm using and with the manifold entrances and exits, inertia changes as the water loops through the coils, etc. I would say that this 1262 can handle the job very nicely. It's definitely looking that way.

Anyway, There is no need for a large Iwaki type pump sucking 140-240w out of the wall. My intent/goal here is to gain the most benefit at the least electric cost. An Eheim 1250 offers 6'7" head, 28w, 320gpH. That may not be quite enough, but 2 of them (1 at each rad) would do the job and still only suck 56w. Basically, $4.06/month v. $5.80/month. Not really worth shelling out $200 for....

I used what pepper I have on hand. "Pure Ground Black Pepper" from wally-world. The refill type can. Worked great....so far! I may have to redo it periodically, but all things considered...it shouldn't take too many repeats to clog up the leak. Either way, at this point its not leaking, so life is Good.

Originally Posted by orclev

You are a sick sick man, but in a good way. That's a seriously awesome setup. So yeah, now that we've seen your awesome work, what lessons did you learn from it, and what would you do different the second time?

Thanx! See below....

Originally Posted by Unseen

crazy people...

Trust me...I prefer Crazy over normal. Normal people don't enjoy their life as much as I do....

Originally Posted by Quad-Damage

how loud is that setup

Hard to say really. I would guess that its about as loud as a 5K-8K window A/C when the compressor is on and the fan on high. Not dead silent, but not really obnoxious either. The biggest problem with this exact setup is the car rad fans....they have a slight whine to them. But I could redo things and use the 9" fans like I have on my outside rad...it would be a bit quieter, but suck a little more juice. The 4 80mm PC fans blowing into the bottom half of my setup are considerably louder. Here's a couple of pix so you understand what I talking about:





Plus I have 3x 120mm at the PCs and 3x 80mm.....Its not as loud as it seems--until everything gets shutdown....then I realize that its a mini airport in here.

Anyway, it's no where near as loud or obnoxious as it may sound in that video. I can turn my volume up and make the noise in that video sound like a 747 is taking off in here.

So, w/o the PC fans, etc.....just the car rad fans, psu and pump--its actually very quiet. The pump is silent...that's why I bought Eheim. The psu is very quiet, and the car rad fans are quiet, except for the slight whine...it's very slight, but its there. The PC fans set up the way they are do a good job, but they are considerably louder then the rad setup.

Originally Posted by Plan.B

wow. impressive - from concept to execution. I'd rate that as xtreme. good job!

Thanx!


Ok, so what would I change? Hmmmmm, at this moment I'm not sure really.... Things seem to be looking very promising, but I won't know what the real deal is until this summer.

I would seriously consider going with straight pipe though. Not sure that I would, but I would definitely look into it. Cost v. surface area, etc. Would make it easier to build the manifold et al above ground prior to digging. A copper manifold would give a bit more exchange surface area.

So, all-n-all...right now....I'm not sure what I would change. I guess I'll just have to wait and see how things actually work out.

[shoopdawoopa]

You sir are extreme

[OldChap]

I remember the planning stages.........so good to see this come to fruition .....will be waiting for your summer temps.....This is a digg it for sure

[Naja002]

Originally Posted by shoopdawoopa

You sir are extreme

Thanx!

Originally Posted by OldChap

I remember the planning stages.........so good to see this come to fruition .....will be waiting for your summer temps.....This is a digg it for sure

Same here....on boths counts: Glad to have it done and waiting on summer performance....!

[[XC] gomeler]

That is an amazing project. I'm really interested in seeing the summer performance. I hope the system is able to dissipate all the heat you are dumping into it. Instead could you have used aluminum tubing? Shame to hear about the leak, hope the black pepper trick holds and doesn't impede performance too much. Keep us updated, I've always wanted to implement a system like this but never had a permanent house to do it at.

[HDCHOPPER]

glad to see you got it done exellent job man !!

[[XC] Hicks121]

So Naja, can I borrow your backhoe?

[npk]

Next time when the wife says I´m crazy, referring to the way I cool my rigs, I´ll show her this thread! now that´s what I call extreme cooling.