I have a running argument with my husband who thinks that more mass transit will solve everything. But he will not step foot on a bus. Buses are for everyone else but him. He would be embarassed to walk to the grocery store and be seen carrying a bag home. It is that type of denial I think is holding us back. He doesn't want dirty nuclear power, but no way is he going to put money into a windmill, solar panel, passive solar system for himself or ever ever trade his dream of a Humvee or SUV for a putt-putt electic or complex hybrid car. There are the people who just want to drill for oil to the last drop. There are those who want everyone else but them to use buses, trains, windmills, solar cells and imaginary fuel cells. Then there are the few pioneers who make the sacrifice to actually live with some of the new technologies. What I see is most people won't volunteer to make their life harder. They are happy to make everyone else sacrifice. If we slow down using oil right now the holy trinity of windpower, solar power, and someday feasible fuel cells won't keep our system moving. And I do worry about running out of oil for other reasons. So many modern materials are made only with oil. Critical plastics (as used in in pacemakers, heart stents, shunts, I.V. bags, catheters, lab equipment, disposable needles...) , glues, epoxies, zillions of items used in the space shuttle, or jet planes, or you name it. Oil is the basic starting material of organic chemistry. Where do we derive things like mineral oil, acetone and all the myriad of chemicals we need? There are a lot of items we can survive without, like plastic storage bins or garbage bags. But so many items don't have an alternative. Let's see, DVD's without plastic? There are plastics made from plant material but a full replacement of critical items just isn't there. Maybe we can't afford to grow enough corn to condense down into replacement plastic for our yearly critical needs without ruining the soil. After all it took millions of years of crop cycles to accumulate the oil we use now to make all this stuff. I would rather save the oil for future generations to use for the building blocks of organic chemistry.

Re: doogan Copper is still the Âgold standard in plumbing. How often do the cold water mains into your house have to be changed, every 50 years, give or take? Why? Usually not because of corrosion, but because of restricted flow caused by a buildup of mineral deposits. DX ground loops should last 50  75 years. Should the refrigerant leak itÂs probably more of a hazard to the atmosphere than to the ground or ground water. The liquid anti-freeze in a conventional geothermal system would likely be more harmful to the ground and ground water than Freon. An oil leak, if sever enough, could be a catastrophe both environmentally and financially, which is why we moved away from our oil furnace. I donÂt loose any sleep over our DX ground loops. The whole system has been surprisingly and absolutely trouble free! I kind of view the whole controversy as somewhat akin to the debate of, Âwhich do you prefer, PC or Mac? Personally I prefer the Mac. In the link below, the top picture with the blue drill rig was taken in our front yard next to a flowerbed. The drill bit sticking up out of the ground is the size of the borehole, only 3 inches in diameter. The entire Âbore field is not much larger than that patch of grass in the picture. This company did not do our installation, but Âlifted the picture from elsewhere on the net. SR Here is a link that might be useful: Lysair

Where do you live? How big is your home? What sources of energy are available to you; at what rates? Has a Manual J heat gain/loss calculation been done? Has a Manual D calculation been done to design a forced air duct system? The old radiators would have been used for heating only. Chilled water would not have been circulated to the old rads in A/C mode, as condensation would form due to sweating. However, you still have a choice as to the type of distribution method, forced air or hydronic. Force air means installing a duct system as you have been planning, perhaps zoned. Hydronic means installing fan coil units that would be fed by insulated small diameter pipes. That would likely be a far less invasive renovation. The installers may limit you in your area; generally geothermal contractors prefer forced air. Find a geothermal contractor that has experience installing in-floor radiant heating. This would be a better choice. The best choice would be a large HVAC company that has expertise installing all manor of heating systems including geothermal hybrid systems that could be a combination of different technologies and sources of energy. Keep in mind that forced air will require at least 2 or more heat pumps. Liquid to water, hydronic distribution can be done with just 1heat pump. This may also mean a less complicated connection to the ground loop system. As an example of a hydronic fan coil unit see link at bottom of post. These units can heat with water temperature as low as 100ÃÂF - perfect for geothermal! They can also be ordered with hand held remote controls making each unit a separate zone by simply controlling the temperature and fan speed wirelessly. The whole site: http://www.multiaqua.com/ The clients that have converted from oil hot water to geothermal hydronic heating and air-conditioning, including the incorporation of their old radiators, are quite satisfied with the performance. Just find the right designers and installers in your area. SR Here is a link that might be useful: Multiaqua - Think Water!

"The trench would be about 7 feet deep and 1 foot wide, thus, the average depth of the coil would be about 5 feet." This tells me that they would install a vertical Slinky, probably with a backhoe. A chain trencher, 'Witch Ditch' would probably be narrower than 1 foot wide and would be a faster install, unless soil conditions do not permit this technique. Avg. depth of 5 feet could mean that the loops are 4 feet in diameter meaning the top of the loop may be only 3 feet below the surface. If this is so, then this may not ideal. Top of the loop should be at least 4 feet deep (minimum) or deeper. Digging should be contracted to someone with the right equipment (chain trencher, 'Witch Ditch'). Even then this may be less than ideal in that it's harder to flush a vertical slinky (standing up) than a horizontal slinky (laying flat) in that any trapped air will reside at the tops of these vertical loops. This trapped air could be a serious impediment to liquid flow as it may form an air lock thus shortening or short-circuiting the entire loop. Bottom line in plain English, it will work - if properly designed, installed, purged and FLUSHED! SR