The Hole…Geothermal Loop…56K Warning!

Oooo... someone is getting defensive because they might know Im ri---ight.....

I did typo the Kw/h thing, I meant watts/hour. Sorry, I suppose I should spend more time prufe readin gmy posts because others might use it to assert that a typo means Im a total moron (not that its just a typo).

As for the rest of your post, you keep telling me I need to keep researching (I didnt know I was), and that Im wrong. Back up here man... Im trying to help you accomplish your goals here, and you are tearing me down for it. IF you know better, dont just keep claiming it and refuse to SHOW IT. Then you look like an ass trying to point the finger elsewhere. The insulating capacity of the ground outweighs its ambient temperature advantage... thats all Im saying. You are taking an above-ground radiator and burying it... which is counterproductive.

In your vast library of geothermal know-how, there are some key points Im sure you have come across. Geothermal cooling IS NOT run 24/7 in many cases. SOmetimes they are off at night, and only on during the day when it is warmer outside.... it really depends on where you live. Most geothermal setups are not for conducting heat while in use as much as they are designed to be a mass storage sink for heat (or lack of it)... which is why you see many geothermal setups with large storage containers buried underground rather than individual pipes. There are ones with pipes as well, but those are for much larger scale applications where the volume needed would be too immense, so a large area of ground is used, with pipe buried below, etc... but then you ARE talking in kw/h, not just watts. In the case of multiple pipes buried under the ground then (horizontal loop style), the major difference between those and yours (which seems to be the model you are going after) is that they space out the pipes much further and cover a much larger area. The pipes are spaced out at least a foot apart so that the soil can act as a mass storage medium. If thats the model you are going for, then you need to space out those pipes much more... you have 2-3 pipes buried where one will do the same according to that model. If you are going for the vertical model, you need to dig much deeper before you start to see the ambient temps outweigh the storage capacity of the ground.

I already explained how the ground is your weekest link in my last post multiple times, as well as just in this post. If you missed it, read it again... the soil's insulating factor outweighs its ambient temperature advantage. Why would you ask me to explain that again?

I am also not guessing for those BTU/wattage calculations. Some I can calculate from simple thermo equations, and others are just simple algebra based on the industry standard specifications used for finned pipes and heat exchangers. You are using typical internet argument tactics to win your point, but not providing any insight or proof to the contrary. If you have something to contribute to the actual discussion, you can only do it by staying on topic, not by falling back on unfounded personal attacks to discredit me in a tone that makes you seem more intelligent. I think YOU are the one who needs more time to research what geothermal cooling is all about.
 
Sand? No. I would have to look it up again. I considered sand, gravel, marble "chips" and a number of things....ultimately, any benefit was really out-weighed by cost and added hassle.

For some reason I thought you meant to spray the plastic/pond liner in order to help protect it...increase it's durability. In order to do that--it would need to be sprayed from both sides.

A pond liner would work all by itself. The problem for me was that I was going to need to buy a large "sheet" and then have to cut it to fit, etc. I think it was going to run ~$200. Just more then I wanted to add to the project. From what I understand, done properly, a good heavy rain does not seem to offer any benefits to temps. Maybe with a pond liner or such--it might....I couldn't tell you. But ultimately it's the ground that's still going to dissipate the heat. The faster you transfer the heat to the ground--the faster the ground is going to need to get rid of it. And the ground is only going to dissipate at a certain rate.
 
undertheradar said:
Oooo... someone is getting defensive because they might know Im ri---ight.....
Click to expand...

My response has nothing to do with getting defensive. I've been messageboarding for a long time and I don't let people bait me into arguments...especially when they don't appear to know what they are talking about. I don't waste my time with a lot of silly nonsense. So, you can take it any way you want, but that's how it is.


undertheradar said:
I did typo the Kw/h thing, I meant watts/hour. Sorry, I suppose I should spend more time prufe readin gmy posts because others might use it to assert that a typo means Im a total moron (not that its just a typo).
Click to expand...

I thought that might be a typo, but there's plenty of morons running around the net--so, ya never know.


undertheradar said:
As for the rest of your post, you keep telling me I need to keep researching (I didnt know I was), and that Im wrong. Back up here man... Im trying to help you accomplish your goals here, and you are tearing me down for it. IF you know better, dont just keep claiming it and refuse to SHOW IT. Then you look like an ass trying to point the finger elsewhere. The insulating capacity of the ground outweighs its ambient temperature advantage... thats all Im saying. You are taking an above-ground radiator and burying it... which is counterproductive.
Click to expand...

My goal is accomplished. What's done is done...there isn't going to be any changes made--this project is complete.


undertheradar said:
In your vast library of geothermal know-how, there are some key points Im sure you have come across. Geothermal cooling IS NOT run 24/7 in many cases. SOmetimes they are off at night, and only on during the day when it is warmer outside.... it really depends on where you live. Most geothermal setups are not for conducting heat while in use as much as they are designed to be a mass storage sink for heat (or lack of it)... which is why you see many geothermal setups with large storage containers buried underground rather than individual pipes. There are ones with pipes as well, but those are for much larger scale applications where the volume needed would be too immense, so a large area of ground is used, with pipe buried below, etc... but then you ARE talking in kw/h, not just watts. In the case of multiple pipes buried under the ground then (horizontal loop style), the major difference between those and yours (which seems to be the model you are going after) is that they space out the pipes much further and cover a much larger area. The pipes are spaced out at least a foot apart so that the soil can act as a mass storage medium. If thats the model you are going for, then you need to space out those pipes much more... you have 2-3 pipes buried where one will do the same according to that model. If you are going for the vertical model, you need to dig much deeper before you start to see the ambient temps outweigh the storage capacity of the ground.
Click to expand...


Right. You got it. Thank you. That's the #1 main flaw of this project--too much dissipation ability for the amount of ground. The other flaw was a question from the start--how deep do I need to go? Well, I did not go deep enough. So, between those 2 flaws this project turned out mediocre at best.


undertheradar said:
I already explained how the ground is your weekest link in my last post multiple times, as well as just in this post. If you missed it, read it again... the soil's insulating factor outweighs its ambient temperature advantage. Why would you ask me to explain that again?
Click to expand...

It's the wording that throws me.




undertheradar said:
I am also not guessing for those BTU/wattage calculations. Some I can calculate from simple thermo equations, and others are just simple algebra based on the industry standard specifications used for finned pipes and heat exchangers. You are using typical internet argument tactics to win your point, but not providing any insight or proof to the contrary. If you have something to contribute to the actual discussion, you can only do it by staying on topic, not by falling back on unfounded personal attacks to discredit me in a tone that makes you seem more intelligent. I think YOU are the one who needs more time to research what geothermal cooling is all about.
Click to expand...

No, actually I'm not. I am simply placing the burden where it belongs. I just went through this same stuff (different topic) with a clown that started telling me that I needed to explain (disprove his claims) and what experiments I needed to do. No, he can prove his own claims and do his own experiments. I'm not doing his work for him. That's internet tactics...and I don't go for it. I am more then happy to save my time and my energy by just drawing the fool out to prove themselves a fool. It's not my responsibility to give them the answers that they can then play off of.... If they are not a fool....then we all have something to gain.


I am glad for your response. If you didn't have any idea--you would not have "guessed" the insufficient ground. Kudos to you.

I posted the last post of this project to let everyone know that this did not turn out as well as planned. I had an HVAC engineer tell me about what the result would be and why, but that was right after the fact. So, even though it's someone that I know and respect--I was still kinda hoping they would be wrong. It's not a total loss, but if I had spread out the piping and went deeper the result would have been considerably better.

Again: Kudos to You.
 
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Naja002 said:
Sand? No. I would have to look it up again. I considered sand, gravel, marble "chips" and a number of things....ultimately, any benefit was really out-weighed by cost and added hassle.

For some reason I thought you meant to spray the plastic/pond liner in order to help protect it...increase it's durability. In order to do that--it would need to be sprayed from both sides.

A pond liner would work all by itself. The problem for me was that I was going to need to buy a large "sheet" and then have to cut it to fit, etc. I think it was going to run ~$200. Just more then I wanted to add to the project. From what I understand, done properly, a good heavy rain does not seem to offer any benefits to temps. Maybe with a pond liner or such--it might....I couldn't tell you. But ultimately it's the ground that's still going to dissipate the heat. The faster you transfer the heat to the ground--the faster the ground is going to need to get rid of it. And the ground is only going to dissipate at a certain rate.
Click to expand...

Hey Naj,
The only reason why I asked about sand, was because it doesn't absorb water. Dirt does. But sand would allow you a greater volume of water in the same area. At least that's what I'm thinking here. I'm thinking that once the dirt becomes saturated, there will be no movement of heat in the water. I'm not sure where I'm headed with this. For some reason, I'm thinking that once the soil is heated, it won't disperse the heat. But the sand mixture would do a better job of transmitting that heat away.

Again, I'm only speculating. I really need to think it through more.

Shingoshi
 
The sand is a better thermal conductor than regular dirt because it contains less air... unless they are both wet... then the dirt might win out.
 
undertheradar said:
The sand is a better thermal conductor than regular dirt because it contains less air... unless they are both wet... then the dirt might win out.
Click to expand...

Ok. I was thinking that having wet sand would conduct heat away better than wet dirt. I was thinking that between dirt and sand, sand would have the higher water content per volume.

Shingoshi
 
Shingoshi, In the end you are going to wind up limited by the dissipation ability of the ground that you are dealing with. "Soil" ranges from not much better then stagnant air to ~2. No matter how fast you move the heat away from the pipe's surface...if the load is too much, then you will still run into the earth's insulating factor that UTR mentioned above. The heat is only going to dissipate as fast as the weakest link will allow. It's still the earth that will be dissipating the heat in the end<--if that's the weakest link, then that's the weakest link. Adding a higher TC medium won't help on a 24/7 load, but may very well on an intermittent load.
 
Naja002 said:
Shingoshi, In the end you are going to wind up limited by the dissipation ability of the ground that you are dealing with. "Soil" ranges from not much better then stagnant air to ~2. No matter how fast you move the heat away from the pipe's surface...if the load is too much, then you will still run into the earth's insulating factor that UTR mentioned above. The heat is only going to dissipate as fast as the weakest link will allow. It's still the earth that will be dissipating the heat in the end<--if that's the weakest link, then that's the weakest link. Adding a higher TC medium won't help on a 24/7 load, but may very well on an intermittent load.
Click to expand...

I don't think I have any more questions about this. I understand (and accept) what was being said earlier as being one of those incontrovertible facts.

So I guess the best possible solution would be to have an underground stream of moving water. And unfortunately, we can't create that.

Shingoshi
 
naja is a cooling freak of nature. I think that's the most elaborate, bad-ass cooling set up I've ever seen.
 
Shingoshi said:
Ok. I was thinking that having wet sand would conduct heat away better than wet dirt. I was thinking that between dirt and sand, sand would have the higher water content per volume.

Shingoshi
Click to expand...

Well, I said 'might'... it really depends on the dirt.. some has alot of clay, some peat, some sand, etc. When dry, the sand will pack in more leaving less air space which will act as an insulator. When wet... Im betting on the soil taking up more water (in the gaps)... but nobody except the owner can say for sure. Its also hard to say, but one might actually drain water more than the other, and water movement could play a huge role with this.

I dont think the concept is a dud though. I think there are ways to make it still work.
 
Maybe some of you have seen or know what I'm talking about here. But I think I remember something resembling rigid steel wool with the structure of a open-cell foam. In other words, it's not flexible. I was thinking that if someone could find something like that, they could use it to blanket the bottom of the basin. If all else failed, you could simply use steel wool. But that would soon rust and be of no use. You would NEED a stainless steel wool.

Or, you could place regular steel wool in the still wet concrete floor I mentioned above. That way, when the wool rusted and decomposed within the concrete, there would be vacancies in the concrete. The concrete would still be strong. It would simply have pockets which would ultimately be filled with water. And it would be more likely then that water could move about more freely than it would if we only had concrete in place.

But I think I'd prefer the rigid stainless steel blanket. It would have the strength to hold the soil above it. I can't even think of what it's called to look it up on the net. If there were anything like this made from polypropylene, that would work too.

===============================================================================================================

Oh! I really have to stop doing this! But here's yet another of my ideas. If the point is to increase the amount of water surrounding our PVC tubing, the better solution would be to make a set of tubular heat-exchangers underground. And this is NOT a complex problem. Here's the solution:

First of all, make sure you have dug the proper depth for your pit.

1.) Take as many 4" pvc tubes as desired. these will eventually be laid flat on the basin floor.
STEP TWO CAN BE DONE ABOVE GROUND TO MAKE WORK EASIER!!
In fact, I strongly recommend doing this. Above ground, with your 4" tubing laying flat, wrap the poly tubing inside the larger tubing. Use a cord with some sort of hook on it. Pull the poly tubing through the larger tubing using the hook and cord. Your spool of poly tubing will remain in one position. What you'll end up with are folded runs of poly tubing inside of the larger tubing.
2.) Insert your poly tubing inside the larger 4" tubing.
3.) Leave enough space for groundwater to move freely inside the larger tubing.
4.) To better facilitate the movement of moisture, it might be best to have the 4" tubing laid slightly off horizontal. In other words, it should have a slight slope.
5.) Edit: Following my advice above, this step isn't necessary! Make all of the necessary connections with all of the tubing. However, if you use ONE CONTINUOUS TUBE of poly, you would only need to connect each of the ends.
6.) Temporarily seal the ends of the 4" tubes with plastic. It might even be better to create long strips of plywood to support the 4" tubing. You'd essentially want to create what looks like the frames used for making pre-stressed concrete. Come to think of it, this is the better solution as you will see later.
7.) Depending on the length of the 4" tubes, use multiple plywood supports between the ends. You'll now a box to pour your concrete into.
8.) Pour concrete over the 4" tubes.
9.) Let the concrete set. Make sure it's completely rigid.
10.) Remove the temporary seals on the ends of your 4" tubing.
11.) Now fill in the bottom half of your basin with sand.
12.) Fill the remain vacancy with soil.

I guess anyone could use wood palettes for the structural support surrounding the 4" tubing. Palettes are very easy to find, or even make yourself. The wood will eventually rot and decompose, leaving only the concrete behind. But you need at least 2" above and below the palettes/tubing to ensure the weight of the ground doesn't cause this structure to collapse. Depending on the overall size of your basin, all of this could be done underground if you prefer. Just make sure you have plenty of room to work in, not to cause undo stress or hazard.

Project complete!

Shingoshi
 
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Well, air acts as an insulator unless you actually use something to move it through the radiator section. In which case, I would ask again... why go 'underground' then in the first place? Working with soil and dirt and the lower ambient temps under soil are best for systems that are not running 24/7, are buried very deep, and/or spread out across a large area. Otherwise, an outdoor radiator, esp if passive, is best left above ground so the radiator can easily pass heat to the surrounding air (or water), and benefit from the natural air movement outside.

You could... spread out the pipes... copper or pex, to be at least 12" apart and cover at least a couple hundred feet in the front yard. The soil still acts as a thermal storage mass, but it can convect some now. Usually for homes that use this, its done so that during the day, the water is cooler... yet overnight, the water is then warmer (so its ideal for places with hot days and cool nights)... not exactly ideal for a 24/7 setup (although if you wanted to store the heat from the computer to heat your home at night.... thats one possibility). The only way to get 24/7 cooling from geothermal that never seems to run out is to do a vertical loop... going several hundred feet down where its always cool. This is a bit absurd though for a computer, and sometimes even a house. Otherwise, burying large poly tanks in the dirt is almost as good, but only if you are talking half-day use, and half-day left to cool.

So there is the 'outdoor radiator' option. Aluminum would be better, like the finned pipes I use for my setup, because it wouldnt break down like copper does outside. Copper also heats up in the sun more due to its color, where aluminum does not. Copper pipes could be kept outside if protected by an overhang (from both the elements and sun), but this might also restrict the airflow/wind.

Another thing to look into might be to use the ambient temps of the well or city water coming into your home. This sounds like it would be wasting water, but its not. If you can gain access to say, your well and a neighbors, or two different tap locations from the city feed that are far enough apart... it would work. The main idea would be to use a pump and heat exchanger... taking in cool water from the street/well and keep it in a closed loop with a pump. Since the pump would be drawing from a supply that would be at the same pressure it is pumping into, it wouldnt have to work very hard at all, but it would likely have to be a higher pressure pump just to handle the static pressure of the water supply. If you ran this water through a heat exchanger that would act as the radiator for your computer system... there is no telling how much you could cool. You would have a potential for cooling amounts only limited by the water flow and the size of the heat exchanger. Since all the water you take in would be pumped back to the supply, your net water use would be 0. I dont know how the utility company would feel about this, since you would have one meter running forward as well as another in reverse (or if that is even possible). If you live in a dense area, or a multi-unit dwelling, you most likely have multiple water supply lines and meters anyways... just take from one, and pump it back into another (as long as both go to the street, otherwise, you are just running a loop in your home). On the cool side, you are heating everyone elses water, which Im sure they wouldnt mind, esp in winter. Even if the supply lines to the street were close together (so the for your outgoing water coming back in), if you are in a populated anough area, those lines are most likely being used by many others at the same time so anything you heat up will likely be carried away very fast. Now that I think of it, I would love to do something like this as a source of free cooling (well, you have to pay for the circulation pump electricity) for my whole house. 'City Water' cooling...lol.
 
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