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  • Geothermal - Home Built

    Dose An One Know Of Any One Making A Home Made Geothermal Home Heating System? Plans - Information? I Would Like One But Think The Prices Are Outrageous. Richard

  • #2
    I don't know much about geothermal energy, but I looked my lab's website and maybe the following link may help you.

    http://www.nrel.gov/geothermal/moreinfo.html

    and the following article describes some proposals sent to NREL regarding power generation from geothermal sources. Although the scale is much larger than a single home, maybe it will give some ideas.

    http://www.nrel.gov/docs/fy01osti/30275.pdf

    Good luck,

    Jesse

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    • #3
      Geothermal

      Originally posted by Richard Hanley
      Dose An One Know Of Any One Making A Home Made Geothermal Home Heating System? Plans - Information? I Would Like One But Think The Prices Are Outrageous. Richard
      The equipment price is in line with what a top of the line gas 96%+ furnace would cost. It is the well(s) or loop costs and the price of the special thermal welded plastic pipe. You will need one well (bore hole 200 ft +/- deep) per 12,000 Btu's or 500 to 700 ft of loop for each 12,000 Btu's in this area. Most loopers or drillers in this area (Iowa) are booked about 4-6 weeks in advance. A 200 ft bore hole in this area will run you about $1,500 - 2,000. That price includes the pipe and loop running / welding. The hook up and installation of the equipment is additional cost. Don't forget the duct work. The load sizing is a VERY important part of the job, few fly-by-nighters even know about a Manual J (building) load calcuation and loop sizing, let alone be able to do one.
      My suggestion... do what I'm going to do, insulate the house very well and then put in an air source heat pump with a High Eff. gas furnace. Good Luck.
      Retired - Journeyman Refrigeration Pipefitter - Master Electrician - Fine Line Automation CNC 4x4 Router

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      • #4
        Richard,

        This might give you some ideas:
        http://www.igshpa.okstate.edu/about/about_us.htm

        Read the "history" section.

        For convenience, here's the home page link:
        http://www.igshpa.okstate.edu/

        I would strongly recommend that you look into a ground source heat pump setup such as this. I understand that you think the cost of the commercial units is excessive, however, it may prove to be cheaper in the long run. The reason I say this is that the heat pump unit itself is not too much more expensive than a regular furnace/air conditioner unit. The main cost of putting in such a system is the installation. You must either dig fairly deep trenches (about 4-6 ft.) or drill vertical wells. If I remember correctly, you need about 200-250 feet of pipe per ton of capacity in a vertical well.

        It looks like somebody else beat me to it already... oh well.

        You do have a couple of options for laying pipe besides wells; you can put in horizontal loops, which may be slightly more cost-effective but requires a lot of space, or - the easiest and cheapest option - a pond loop, which has, not surprisingly, a loop of pipe in a good-sized pond. It has the added advantage of your pond not freezing in the winter, unless you live someplace really cold.

        As I write this, I'm only about 100 ft. from the IGSHPA headquarters, so if anyone wants more information, I'm sure I can find it.

        -Brian

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        • #5
          This is an interesting site if you are building. Long read but well worth it.
          http://www.mb-soft.com/solar/saving.html
          Making chips is more fun than fixing cars.

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          • #6
            Is it possible to convert an air-source heat pump to geothermal?

            Comment


            • #7
              "Is it possible to convert an air-source heat pump to geothermal?"

              Yep, I've done it with a small window-type air conditioner. I just cut off the lines going to the "outside" coil, and put in a water-cooled heat exchanger by running about fifteen feet of refrigeration tubing inside some larger copper tubing. I had the AC mounted in the loft of a cottage where the outside of the unit was in an attic space. The water was provided by my deep well, and dumped in a nearby drainage ditch. The small unit didn't use all that much water. It worked fine for the couple years I was living there. Of course, this was way back when you wouldn't be breaking any laws doing that sort of thing.

              Roger
              Any products mentioned in my posts have been endorsed by their manufacturer.

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              • #8
                The first consideration is where do you live? The climate is the main determining factor as to whether it is practical. The next major consideration is the type of soil you have.
                Free software for calculating bolt circles and similar: Click Here

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                • #9
                  North Texas/DFW, on a rocky hillside.

                  Motodad, that's a very interesting site you posted.
                  I've been wanting to do just that for many years.
                  Can't do it at this house though.

                  Comment


                  • #10
                    As some others have pointed out the geo units are very expensive to install. A typical 3.5 ton geo installed will be $9-10K. A 13 SEER standard unit is under $5K. One will never break even on the additional cost of installation vs electricity used. If the geo ever breaks the savings are further reduced, high price for parts.

                    Air cooled units can be had up to 20 SEER. They are also so expensive there are precious few sold. Their price is close to a geo unit installed. This is due to multi speed compressor and vfd on the indoor fan. All parts OEM and all high as a cats back to repair.

                    I just ordered my brother a new 2.5 ton Trane heat pump split system for $1850. We will change it out this weekend. He will save over $4K from a geo system. Thats a lot of electricity with an average bill of $100. In effect, 3.33 years of free electricity.

                    As far as the home made angle goes this is the paradigm. The only differance would be using water instead of air for heat transfer. The high dollar vfd compressor and indoor fan most likely would not be used. The water must be pumped by something, a pump. That pump will use electricity, just as a fan motor does. The only differance is the effeciency between the two heat transfer mediums. Plus, the effeciency dropps off as the pipes corrode and/or fowl over time.



                    James

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                    • #11
                      North Texas on a rocky hillside. I suspect it may not be practical. You certainly have high enough ground temperatures to make it feasible but the second factor comes into play. For ground loop geothermal to be effective you must have soil with good thermal conductivity. Dry rocky soil does not fit that description. The heat transfer is directly dependent on the amount of water in the soil as it is the water that has the real heat storage capacity and the ability to conduct that heat to the geothermal system.

                      Also, if you have rocky soil installing a system could be very difficult and expensive. Have you ever tried digging any deep ditches on your property?
                      Free software for calculating bolt circles and similar: Click Here

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                      • #12
                        here is the link for the home power magazine.http://www.homepower.com/
                        Also don't remember what issue/isssues it was in but when the mother earth news was a real outlander magazine. they did a number of articles on the all types of mass thermal heat storage and geo thermal stuff. If you can find them the black cover whole Earth catalogs (Internet style info before the computer).
                        Had info on it. the white covered one the last one was sort of suburbaned BS so bad it sucked harder than gravity.
                        Glen
                        Been there, probably broke it, doing that!
                        I am not a lawyer, and never played one on TV!
                        All the usual and standard disclaimers apply. Do not try this at home, use only as directed, No warranties express or implied, for the intended use or the suggested uses, Wear safety glasses, closed course, professionals only

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                        • #13
                          water to air

                          For what it is worth, I built a new house and moved into it about Thanksgiving of 1984.

                          The house had a Friedrich 3-1/2 ton geothermal unit installed at less than $3000 (IIRC) including all the ductwork,registers,thermostat,etc.

                          The well, which also furnishes potable water for the house, is only 60' deep. The heat pump is supplyed only with uninsulated copper tubing and the discharge when cooling is pea warm and cold when heating.

                          There are two power meters, one for the house and one for my shop. The house meter runs $160 to $170 pe month while the shop runs about $20. The well pump is in my shop. There are no supplemental heat strips. The house is about 2700 sq.ft. and the heat pump does a wonderful job year around. If it ever quits (22 yrs. now) I will do my best to find another just like it. I live in North Central Florida.


                          Jim W.

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                          • #14
                            A friend of mine is getting too old to fool with wood heat anymore so he had a geo unit installed .
                            His place is on a rocky hill top here in Southern BC.
                            All I know is, he's happy with it and it cost him $12,000 Cnd. I think they had to drill a couple of fairly deep wells.
                            Too rich for my blood but I'm seeing more and more of these systems being installed around here.
                            Russ
                            I have tools I don't even know I own...

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                            • #15
                              James you make a good point about the systems needed fans and pumps & fans.

                              A goverment contractor did a house in Idaho with a different form of heating. Since this house was located in the north, the emphasis was focused around heating rather than cooling.

                              On to the technical part. One large room of the basement was filled with large river stones. Most of the south exterior wall looked like a solar panel. Air was moved through the panels during the day and into the house and into the rock room. Both the house and the rocks were heated during the day light hours. Once dark, the rocks acted as a large heat sink to enable the house to be warmed by sending air back through the rock room.

                              While it was a neat idea, the person that bought the house was told that the energy needed to move the air was close to that needed to heat the house by convential means. So half the basement was lost without much benifit.
                              John

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