Ground Source Heat Pumps

[Conner]

I'm curious whether any of the contractors here have experience installing ground source/geothermal heat pump systems. Have people seen vertical or horizontal heat exchange elements as more common or cheaper? Can they be combined with the drilling of water wells and/or excavation for the foundation? What about using a system to heat and cool multiple buildings, for example a main house and a detached garage and/or small workshop building? Thanks.

[Solar Dave]

Hi Conner,
I am not a geothermal installer but I have had a system installed here on my property in Ferndale WA.
I have lots of pictures of the horizontal pit installation if you are interested.
Ours is only used for heating. It is working at present to heat a 16' x 30' room in our shop building and will be connected to our new solar home when I get to that point in the construction. It is a 4 ton system.
Send me a PM so we can link up by email if you want to.

[ZehBOSS]

Hi Guys,

In my experience geothermal heat pumps seldom pencil if the home is build truly energy efficient in the first place. An extra $10K in insulation, $5K in better doors and windows and a good HRV and your heating and cooling load becomes very small.

R-60+ on whole envelope, R-10+ windows, 90%+ HRV, solar orientation, thermal mass and the need to pay for heating or cooling of any kind approaches 0.

Build a better home not a better heater.

On the other hand Geo loops are location cost sensitive. Well drilling costs very drastically around the country from $4 to $70 per foot. Frost depth and climatic conditions matter. Be careful about putting the loop around the foundation. I know of a case were the loop froze water next to the foundation and moved the building 2 inches from the man made heave.

Large loops for multiple buildings are fine. You need to size the loop with capacity to spare. The larger the loop for the most part the greater the efficiency of the system will be and the less chance of problems later.
It is possible to build a 100% solar thermal system typically for the same cost as a GSHP system, though they are custom installations and very few people understand how to make them work properly.
Just 2 cents,

Brian

[thermodix]

I think you may try to check this out guys about some kind of heat pump like vertical geothermal heat pump and horizontal geothermal heat pump... http://apps1.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12650 hope this help you a little guys....


_________________
Programmable Thermostats (http://www.prothermostats.com/)