Re: rychnc "I have a pond nearby so I plan to run loops though the water." If you have a suitable pond to run your loops in youve got it made! This is probably the least expensive way to do geothermal, no drilling (except through your foundation wall), minimal trenching. Whats to think about (providing its permitted)? Re: cookingpassion Geothermal systems using copper tubing in the ground loop are called DX or Direct Exchange systems and run the refrigerant through the copper tubing in direct contact with the ground. Theyre great systems providing your ground is ph neutral. Regular systems use high-density polypropylene pipes in the ground circulating some kind of antifreeze. This necessitates the use of an additional heat exchanger and a circulating pump as well as boreholes being about 40% deeper and twice the diameter resulting in higher drilling cost. We have a DX system; never had a problem with the boreholes GREAT SYSTEM! However, I always play it again in my mind, were we to it again, would we go DX? Im really not sure. Both systems have their advantages. I would probably go for conventional only for peace of mind and to distance myself from this whole controversy. My wife on the other hand, who is a supremely intelligent and knowledgeable lady says, Look, we know the ground is ph neutral; since when have we ever had a problem with the tubing in back of a fridge? Thats the simplified version. Its a tough call especially for an IGSHPA accredited installer. SR I can no longer find the link on the copper.org site to this interesting fact sheet about copper, so Ill just copy and paste. Its rather long, I apologize. Breeze though it if you like. About Copper What's Your Best Buy Today? Copper or Plastic? When comparing geothermal systems, compare the value and benefits of copper compared to the plastic pipe used in water source geothermal systems. No heating and cooling piping product is totally immune to all problems. However, for more than 60 years copper-based products have continually proved themselves to be the most robust and reliable for all kinds of heating and cooling systems. There was a time when we were limited to a relatively small range of basic materials from which to make things: wood, stone, iron, brick, leather, cotton, wool, and of course, copper. Copper is man's first, and still most indestructible non-precious metal. Because copper withstands corrosive elements better than any other engineered metal, it long ago set the standard for plumbing systems. The 1940s fostered the Age of Synthetics, an era of technological change. It was the natural outgrowth of an economic system that stressed mass production and sought substitute materials which would do the same job for less money. Manufacturers looked at plastic for a wide range of building products-especially plumbing. Lower first cost, rather than long term reliability, was the driving force. Recently, however, we have seen a growing reaction to this "throw away" economy. Consumers realized that the "cheapest" was not necessarily the least costly in the long run. In many cases, they found that some of the old, basic materials are still the best, still the most economical, because they last and give years of reliable trouble-free service. Copper or Plastic? Here's why generations of homeowners and professionals in the building community feel copper is the best and most economical material: * Copper plumbing has a 60-year track record of nationwide acceptance for water, waste and space conditioning use. * Rigid standards govern the composition and properties of copper products for specific applications. And all products can be tested to ensure conformance to these standards. * Precision and control in manufacturing assures a quality product and long service life. * Copper tube products have permanent product identifications, including type size manufacturer and country of origin. You know what you're installing. Inspectors and owners know what's been installed. The manufacturer backs up the product. * Nationwide, codes and standards assure reliable installations. * Refrigeration contractors have more than a half century of know-how, experience and customer satisfaction with copper tube and fittings. * Copper systems can be installed, tested and used year-round at any temperature in any climate. * Copper systems can be tested immediately after installation. * Copper is not damaged by either near-freezing or boiling water temperatures. * Copper requires virtually no maintenance and can be protected more easily from damage than plastic. * Copper's superior thermal conductivity provides superior heat transfer. * Copper can be stored or used anywhere, indoors or outdoors, without harm or deterioration by the sun's ultraviolet rays or other weather elements. * Copper is non-flammable. Unlike plastics, it doesn't burn or melt or support combustion. It maintains pressure even when subjected to flames. * Copper will not "pipe" flame through walls or floors. It does not violate the integrity of fire blocking. * Copper plumbing products do not give off toxic gases when exposed to fire. * Copper tube is rigid, requires fewer supports, and does not sag over long runs. Copper, unlike plastic, will not fail from the "rubbing" or abrasion normally encountered in service. * Copper tube is flexible (whether it's hard-drawn or annealed) and has a smooth "polished" interior - which means it's easily installed anywhere and will not impede the flow of refrigerant. * Copper silver soldering is a safe, reliable and non-toxic operation. * Copper is fatigue resistant. Copper systems do not present the problems associated with excessive and repeated contraction caused by extremes in temperature. Well-installed copper joints are for keeps, they will not break down or pull apart. * Copper scrap has a high value when sold for recycling. It ecologically friendly. * Copper does not rely on domestic or foreign oil production for its manufacture. * Copper tube is all natural. No synthetics are introduced or used in its manufacture. It is environmentally friendly. * Copper is a noble metal combining extraordinary corrosion-resistance and high strength for refrigeration piping applications. * Copper tube and fittings can, if necessary, be disassembled and reused. * Copper plumbing, like copper wiring, has recognized quality and value that helps sell (or resell) your home or building. * Copper plumbing protects your home investment. It's an insurance that pays dividends year after year after year. * Many decades of in-service experience have proved copper's reliability. It will outlast the life of the mortgage. * Copper systems are the worldwide refrigeration standard of excellence. * Copper has eight times the thermal conductivity of other metals and is the material of choice for high performance, high efficiency heating and cooling systems. Due to its high performance characteristics, copper is the material of choice for American Geothermal(R) DX direct exchange geothermal heat pumps. * In the United States, nearly 50 percent of the copper used each year comes from recycled sources. Copper is one of the most highly recycled materials and can be used over and over again, helping to preserve natural resources and the environment. * Copper plumbing products offer unbeatable quality and value. * Copper tubes and joints are strong. They can withstand pressure surges and rapid temperature changes without rupturing. * Copper plumbing lasts. Copper doesn't become brittle with age. Once installed, it stays installed. * Copper is an investment. When the time comes to sell your home, the quality of copper refrigeration piping and plumbing can actually enhance its resale value. Copper is the right choice no matter where you live. It meets or exceeds all standard refrigeration and plumbing codes in all 50 states. * Decades of successful service say, "You can trust copper." For more information on the value, benefits and technology advances of copper visit the Copper Development Association web site at www.copper.org

Re: US Dept of Energy Interesting that the info on the link provided was on the 'Your Home' (residential) page. "Fairly high efficiencies (300-600%)" is in error in my opinion. The latest, 'greatest', most efficient GSHP with variable speed everything (compressor, blower fan motor & flow center) boasts a COP of up to 6 (600%) with their 6-ton HP in partial load heating mode in an open loop configuration (see page 38 in link below). They don't mention from what depth they're pumping this water. One would have to assume that unlike a closed loop which is a balanced system (water coming up equals water going down) that the water table would have to be very near the surface to avoid high wattage pumping from a deep well and that according to their published specs requires an Entering Water Temperature (EWT) of 80 degrees F. GOOD LUCK IN BOTH CASES! If you're living somewhere that the ground temperature is 80 degrees F in the winter - there's a good chance you won't be needing much heat! Regarding COPs above 6 (600%), I have been involved in projects where the proposed system efficiency was 700%. One such example was an integrated single geothermal system operating between 2 closely spaced municipal facilities. One was an indoor skating arena, the other a municipal garage. The way it works is that the heat extracted from the water to make the ice for the skating rink would be pumped into the in-floor radiant slab of the municipal garage floor - before the use of the loop field in either case. So rather than having 2-separate GSHP systems each with a COP of 3.5 (350%), one integrated system instead of 2 is said to have a COP of 7 (700%) or the addition of the combined output of 2-separate systems. SR Here is a link that might be useful: Waterfurnace 7 Series

Forgive me if I don't weigh in on the political info above. Instead, I'll share our geo experience. We live in Minneapolis, MN, in a 1950's rambler. Approx 1900 FSF on the main, with 1500 FSF in the basement. We had a 28 year old forced air furnace with a similarly old central air unit in the back yard. There was a disconnected fungus farm (humidifier) on the ducting, and the house was usually bone dry in the winter. We were considering a GSHP when we learned of the 30% Federal tax credit, but then the installer we had picked (out of 4 who came and gave us bids), told us of a 35% State rebate (using Federal stimulus package funds), and we realized it was a no-brainer. We spent about $35k for our system, including a Venmar 4100 Hepa ERV that I installed myself, a Honeywell Tru Steam 12 gal humidifier that I installed, a new 200 amp Siemens power panel, with a 100 amp sub panel for the dedicated heat pump only electrical meter), a new 95% efficient Lennox furnace (backup and air handler), a 4 ton 2 stage envision waterfurnace heat pump with de superheater and 55 gallon buffer tank (which I had to plumb in 55 copper fittings to sweat!), and 3 vertical wells 250 feet deep. The system is controlled by a Honeywell IAQ 8000 stat system. Our costs, as stated were about 35k. We received a $9400 rebate check from the state (they didn't allow any rebate on the gas furnace part of the costs, as it wasn't GEO), a $600 rebate from our power company, and a $300 rebate from the gas company. We *should* see a full 30% tax credit on the full system cost when we do our taxes this year. I hate math, so I'll use rough numbers--We should see around $20k in rebates, meaning we'll have around $15k out of pocket. A new conventional system would have cost somewhere between $10k-$15k for an identical high efficiency furnace and central air unit. Again, assume I could have found a contractor to install a conventional system for 10k (doubtful, IMHO), that means I paid a $5k premium for a ground source heat pump over a conventional system. Given that I'm only 40 years of age, and plan to stay in this house as long as I can, we'll see that $5k premium back fairly quickly. According to the Waterfurnace calculations (which may well be optimistic), our averaged monthly utility bills should drop from $246 per month down to $64. Obviously, the short payback on our system is possible largely as a result of govt subsidies. Much like the continued existence of many of our nation's banks and car makers.

I think z\700 is right- nowhere enough water to provide the geoexchange you would need. I need about 9 gpm to supply my three ton open loop system, and the well can supply up to 30. But I have to pay to lift it about 60 feet. I use it once and discard it (back to the acquifer). But you're suggesting using the well with the 173 gallons to immerse a closed loop link. My guess -and that's all it is- is that you'd need several such wells. The 173 gallons is really just not very much, and the replacement level of 1 gpm is nearly insignificant. Again, my guess. But if it were feasible at least your pumping expense would be much less than mine as you would be circulating down as well as up- essentially just overcoming friction with the pump. I hope you get SR's opinion. He may suggest an alternative or two we're not covering. Good luck, M