[Greenbuilding] Ground-source heat pumps; was Re: Green real estate market

[Leslie Moyer]

Steve Tripp wrote:
> One thing I have noticed after talking to several General Contractors about geothermal systems is that there is not a lot of good information out there about reliability and performance.  10 years seems to be average that they
> give these systems to last before requiring major repairs.

This just doesn't seem accurate to me--it goes against everything I've 
heard about them. I'm not connected to the industry at all, but the 
International Ground Source Heat Pump Association is in my state and 
I've heard a lot about them at conferences around here....and there are 
a lot in service around here, too. I might want to look at a motive your 
potential contractors might have for falsifying information....or maybe 
they're just ignorant about them.  Are there no installers in your 
immediate area?  Does their brother-in-law do their HVAC?  Are they, 
perhaps, talking about air-to-air heat exchangers?  Perhaps they had one 
bad sub-contractor.  It is true that this technology hasn't been around 
that long, but all I've heard about them is that the first 
(experimental) ones they put in 30+ years ago are still working 
flawlessly. 

The International Ground Source Heat Pump Association (IGSHP) is a 
non-profit organization: http://www.igshpa.okstate.edu/ based out of 
Oklahoma State University.  About durability, they say:

"*How long will my GSHP system last? *
GSHPs are durable and highly reliable. The GSHP contains fewer 
mechanical components, and all components are either buried in the 
ground or located inside the home, which protects them from outside 
conditions. The underground pipe carries up to a 50-year warranty."

I'd pursue this further, if I were you.....

--Leslie / Oklahoma