Has anyone installed a do it yourself cheap geothermal system?

sylvie

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I saw a geothermal set up where they buried 8 copper lines each 150 feet long horizontally at a depth of 6 ft. They ran to a central feed line to the house to heat. Seemed to work fairly well. I'd think a pump would be involved.

I saw another set up where 300 ft deep wells were drilled and that water was used to heat the floor via pex tubing.

I don't entirely understand the principles of geothermal other than the ground has a constant 54 degree temp. If the ground gets 54 degrees below the frostline why wouldn't a 25 ft well work? We have a ton of nurseries around here with equipment for tractors that drill to 25 ft that we could utilize.

Has anyone installed a DIY geothermal system?
 

FarmerChick

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I don't know much about it.
My contractor and I spoke of it the other day. He says geothermal is a definite good source for the future. He says zoning etc. do not understand it well yet and they have a hard time installing it now in my area. Cause of lack of knowledge about it. Alot of roadblocks getting it passed inspection etc. Hmm..??

I want to learn more also.
 

dacjohns

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My concern with copper would be the copper reacting with things in the soil resulting in faster corrosion and failure of the pipe.

I hope to someday build a real house and use geothermal.
 

patandchickens

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I would betcha that the reason for the deeper well is to have room for longer pipes. You need a *long* length for enough heat exchange. Think of it as the vertical equivalent of the extensive horizontal systems that are more usually installed.

As far as a horizontal system goes, I would be very leery of doing a DIY job, because if it fails (and for DIY I fear that means "when" and probably also "soon"), you have to dig ALLLLLLL that back up to find where the leak is. I do not know about a vertically installed system, but would be very concerned about any DIY installation that used any liquid other than water, because you will be polluting the aquifer from which other people drink if there is any sort of a leak.

I'm sure someone who is professionally familiar with geothermal systems in particular and heating systems in general could design a DIY-style setup for their house that would work pretty well, but I am honestly skeptical whether it's really a good idea to try if you do not have that intimate knowledge of heating systems. If nothing else it is a lot of digging to have to do... potentially twice :p

Good luck though,

Pat
 

enjoy the ride

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I did see one go in once- it was a long trench about 5-6 feet deep and this special plastic pipe was tacked along the sides of the trench, not laid on the bottom. I know the pipe used was meant for this and is very very tough. There was a lower pipe with the return pipe a couple of feet above it. And there were maybe 6-7 long trenches altogether for one house- each trench about 150 feet or more.
I understand there is ome kind of heat exchange device too but have never seen that at all.
 

sylvie

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enjoy the ride said:
I did see one go in once- it was a long trench about 5-6 feet deep and this special plastic pipe was tacked along the sides of the trench, not laid on the bottom. I know the pipe used was meant for this and is very very tough. There was a lower pipe with the return pipe a couple of feet above it. And there were maybe 6-7 long trenches altogether for one house- each trench about 150 feet or more.
I understand there is ome kind of heat exchange device too but have never seen that at all.
Yours is a very helpful post and explains some things that I was trying to puzzle through.
Which brings me to the question of how a heat exchanger works? Would this be a DIY possibility or must it be bought?
 

sylvie

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patandchickens said:
I would betcha that the reason for the deeper well is to have room for longer pipes. You need a *long* length for enough heat exchange. Think of it as the vertical equivalent of the extensive horizontal systems that are more usually installed.

As far as a horizontal system goes, I would be very leery of doing a DIY job, because if it fails (and for DIY I fear that means "when" and probably also "soon"), you have to dig ALLLLLLL that back up to find where the leak is. I do not know about a vertically installed system, but would be very concerned about any DIY installation that used any liquid other than water, because you will be polluting the aquifer from which other people drink if there is any sort of a leak.

I'm sure someone who is professionally familiar with geothermal systems in particular and heating systems in general could design a DIY-style setup for their house that would work pretty well, but I am honestly skeptical whether it's really a good idea to try if you do not have that intimate knowledge of heating systems. If nothing else it is a lot of digging to have to do... potentially twice :p

Good luck though,

Pat
Thank you Pat, your input is always valuable. I hadn't considered a toxic transference by leaks to the aquifer or even my sub surface soil. There is a company that sells DIY geothermal heating kits with tech help for the homeowner but I was hoping that someone who has successfully installed a version could explain the principles.

You are correct about the potential gliches in the lines. We rented a Ditchwitch to dig a deep trench to run a water line from our pond's floating filter to the pump. After carefully laying in the 2 inch plastic pipe, we covered it and got virtually no draw when we started the system. The pipe bent a little upon burying, crimping all but a small bit of a stream. We had to redo it. We now know what to look for in that department!
Pex tubing is more forgiving, flexible and rated for these applications so we are looking at that for the geothermal.
 

sylvie

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dacjohns said:
My concern with copper would be the copper reacting with things in the soil resulting in faster corrosion and failure of the pipe.

I hope to someday build a real house and use geothermal.
Good point. Our soil at 5-6 ft is clay to soft shale, slightly acidic with some iron. The house that used the copper is sandy at 6 ft, but the system has been in use for 15 years.
 

slaghunter

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A geo thermal system using wells do not use pipes for the heat transfer as the horizontal systems do. They actually pump ground water to the heat exchanger and then back in the 2nd well. The wells do not have to be any certain depth they just need to be able to produce a sufficient amount of water. The amount of water needed will be dependent on the size of the heating system installed in the house which of course is dependent on the square footage being heated\cooled.

A geo-thermal system works just like a traditional heat pump. The only real difference is instead of using outside air it uses water. When heating the heat pump draws heat out of the water using freon and a compresser. The water that is now colder is returned to the ground via the 2nd well. When cooling the principle is the same. Check out how a heat pump works for a better understanding.

They also make a unit called a super de-heater that will draw heat out of the warmer water during the cooling cycle that then goes through a liquid to liquid heat exchanger to preheat the water going to the water heater saving even more $$$

I have never installed one myself but a friend of mine had one installed. The whole idea intrigues me so I have been researching them and got as much info from them as i could. Hope this will give you a better understanding.
 
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