wrote in message
oups.com...
Yes. However, he said he was likely to hit basalt within 50', which
makes even the design here impractical:


http://www.copper.org/applications/p...al/cs_stdy_pa1.
htm

http://www.copper.org/applications/p...al/cs_stdy_pa2.
htm


Direct exchange system....

Im guessing you near the west hills else maybe down towards Oregon
City........... some hard rock in both those areas for sure....

The Troutdale aquifer is all sand, and is a perfect area for geo....oh
well.......( pun not intended )

I use all heat pumps, an easy choice since nat gas isnt readily for me and i
dont feel like bothering with propane........

My brother is up north of here, nearer to Seattle, and he uses a heat pump
with gas backup...his having gone through this process just a few years
ago...and so so if I was to advise, I would suggest you should consider
doing the same--that way you can always change over your primary heat source
depending upon what the fossil fuel v/s electricity prices do in the
future......and since you are looking 15 years out and all.....that's just
too long a time span, IMO--and so it becomes more like gazing at a chrystal
ball than it is making accurate economical decisions...anybody's guess.....

--

SVL