This is a really long post - sorry. Don't get me started.
I do Geothermal. In response to Brettski's request I am posting re:geothermal heating and cooling. I have been an HVAC contractor for over 25 years and we put our first geothermal system in about 22 years ago.
Some of the prior information is good, some not. A geothermal system first of all is not really geothermal - technically. A true geothermal system would be one that uses heat from deep in the earth, like the hot springs in Wyoming. A more accurate description is Ground Source Heat Pump. Not as sexy, but more accurate.
As Country Boy pointed out there are 2 types commonly installed - open loop and closed loop. Open loop is also known as "pump and dump". Open loop extracts water from the ground - then either absorbs heat from it or rejects heat into it - then dumps it. Closed loop systems circulate water (with antifreeze in it) in a closed loop in the ground. The water leaves the house and the fluid either absorbs heat or rejects heat depending on if you are heating or cooling.
All of my experience is with closed loop systems. Around my part of Ohio, it is not unusual to have problems with water quantity and/or water quality. If the water has iron and other stuff it it, maintenance of the water pumping apparatus is an issue. If you do not have enough water in gpm year-round, the system will not perform properly. We like closed loop because we avoid those issues. Not saying they won't work - I am guessing maybe 10 or 20% of installed systems are pump and dump - I just do not have any experience with them.
Closed loop systems can use a ground loop that is either horizontal, vertical or in a pond. (magic word - give that man a cigar). We have installed maybe 150 systems. Most have been horizontal as it is the least expensive to install. We use veritcal when there is not enough room for horizontal or the owner doesn't want us to mess up his yard too much. Ponds work great if they are big enough and not too far from the house. 200' from pond to house is a good number but it is always possible to go with bigger pipes and pumps if the pond is farther away - just doesn't always make sense economically. All 3 methods - horizontal, veritcal and pond if installed correctly will work just as efficiently.
Regarding the sizing of the unit - how many tons - that is not a casual consideration. We always use an industry approved method to size the equipment - ACCA Manual J - to see how much heating and cooling is needed. A smaller well insulated house in Illinois would not necessarily need a 4 ton system. More on this if you want it but I think you need an HVAC contractor who will calculate what you need and stand behind it (that is what we do). Let me know if you need more info on correct sizing.
We install WaterFurnace brand systems. We always install polyethelyne pipe for the ground loops. We have a special "iron" that melts the plastic and welds it at the joints - stronger than the pipe (burst). We test our installations as we put them in. Never had a leak. I would never use copper due to potential for leaks and future corrosion. Polyethlyne is the same stuff as garbage bags. Dig it up 40 years later no deterioration. As long as Polyethylene does not see UV rays it is the way to go. Priced copper lately? - they are stealing it as fast as we put it in.
As far as is it the way to go the short answer is yes. This is what I do for a living. I can give you the algebra formulas to compare all the different options you might consider for your home. Geo wins every time. Some examples"
Natural gas w/90% efficint appliance and $10/1000 cu ft = $11 per million btus into the house.(Nat gas wes 50% higher than that last winter in most markets).
Propane gas w/90% efficient appliance and $1,75 per gallon = $21.25/million btu into the house. (they are at about $1.99 per gallon locally here).
Fuel oil - 80% efficient - $2.50 per gallon = $22.32 per million btu into the house.
Electric reistance heating (elec baseboard, elec fan forced heaters, electric water heater, toaster, hair dryer) - if wither electric costs $.06 per kWh (local rates) = $17.58 per million btu into the home.
Geothermal (Ground source heat pumps) deliver 4 times the heat for one kWh vs. elec. baseboard, or a per million btu into the house cost of less than $5!.
As you can see, local costs for the electricity and the various fuels plays into it, but no matter how you slice it ground source heat pumps heat for less. Oh yeah, they also cool for a lot less - very important to our southern friends. Oh yeah, they also typically produce about 50% of the energy needed to heat water (at 25% the regular cost).
There are of course a lot of other things to consider. What is the "upfront" installed cost of the various choices? What local fuels are available? (nat gas not available in all areas). What is the energy load of the building ( a small load that does not use much energy reduces the effect of more efficient choices). Does the homeowner want air conditioning (believe it or not we have customers who do not want A/C. This reduces the value of geo as it is a heat/cool system and it uses rejected heat in the summer to heat domestic hot water). Do you want a tank (LP or oil)? Do you want combusition and the possibility of CO (Carbon Monoxide)?
And now the really serious stuff. What is the maintenance cost? Oil is an annual affair to keep it running efficiently. LP and Nat gas burn cleaner but still require regular maintenance to keep efficiency up and avoid repairs. Geo units are pretty much "plug and play" if designed and applied correctly. Kinda like a refrigerator. Or driving your car at 55 all the time. When we do "annual maintenance" on our geothermal installations, it is like going to the doctor when you are not sick. Check - ok, check - ok, check - ok ,etc. etc. Other than keeping the air filter clean, there is nothing to lubricate or adjust. So "life cycle costs" are much lower with geo.
Lastly - what is the outlook for energy costs? We have seen big run-ups in cost for fuel oil, LP gas and natural gas. Electricity, which used to be considered "expensive" to heat with is now suddenly an option worth considering. What does the future hold? Well electricity is generated mostly from coal which has nearly doubled in cost in the last 2 years (wholesale market). Most electricity generators and resellers are tied into long-term agreements that slow down their ability to raise prices quickly. But increased electric costs are coming. The electric utilities have a product that costs them more to produce, and the customer's other options have increased dramatically. They will be raising prices as soon as the regulators allow it.
So there you have it. Geo 101. Feel free to ask other Geo or HVAC related questions. I will help if I can.
