Replies

1. 
   MSA1 | May 31, 2006 01:38am | #1

   I dont know if using the well would work, but if I were to ever build a house, i'd love to do geothermal. It may cost alot to install but have you seen a gas bill lately?

2. 
   BobKovacs | May 31, 2006 01:38am | #2

   Most likely, you'll need far more than just your existing well.  Most geothermal systems have numerous deep wells, or a huge, shallow area to route a lot of pipe through- one well isn't enough. 

   That said, it doesn't hurt to get some estimates from local geotherm contractors, but be prepared for a big cost difference over a conventional gas unit, and a lengthy payback period.  Last time I checked, the payback was in the 10-12 year range, though it might be better now that gas prices are up.

   Bob

3. 
   Virginbuild | Jun 04, 2006 07:11pm | #3

   The first thing to do is to find out how much water the well will produce in GPM and how long will it sustain the flow. Next how deep is the well and where is the water table in relation to the time of the year. The water table can fluctuate 6 to 12 feet or more throughout the year.

   If you really have a good water supply the next decision is a closed or open system. An open system discharging the water to surface drainage which brings into where will the water go? Most districts now prohibit direct ground injection due to fears of contaminating the aquifer.

   I have a concern about open system discharge because in some areas the aquifers are limited in capacity. If every one went to a geo heat source with open discharge it would draw down most aquifers to where there is not enough water to supply the demand. The best and most environmentally friendly is a closed loop system inserted into one or more wells or a buried ground loop. 

   Virginbuild

1. 
   DonNH | Jun 05, 2006 04:28am | #4

   I was thinking a while back about how to minimize the excavation costs for a ground loop system.  One thought I had was that if you're putting in a septic system, could you run tubing in the same spot while it's open?

   Issues would be whether the cooling/heating from the tubing loops would affect the critters in the septic system (go deeper with the tubing?) and what happens if one system leaks into another.

   I can't be the first to think of this - anyone heard any discussion about it?

   Don

    

1. 
   peteshlagor | Jun 05, 2006 08:08am | #5

   Yeah, I asked my installer about such a deal.  He said, " You wanna fix a repair in the pipe UNDER a drainage field line?  I don't."

    

2. 
   Virginbuild | Jun 05, 2006 01:35pm | #6

   I too, wouldn't feel comfortable digging around the septic tank or the drain field for any repair to the ground loop. Another factor is the drain field is not deep enough for the ground loop. Except for the depth at the bottom of the septic tank, drain fields only go down a few inches below the surface. The ground loop has to go several feet below the frost line, deeper the better.

   Virginbuild