Geosolar/Geothermal

[thefish7]

I'm starting to get into some planning on buying a bit of land and building a house on it and one of the things my wife and I have talked about are some "green" features. I was wondering if anyone here has any experience with geothermal heat pumps / solar water heaters and/or some combination thereof?

[kahnduit]

I'm starting to get into some planning on buying a bit of land and building a house on it and one of the things my wife and I have talked about are some "green" features. I was wondering if anyone here has any experience with geothermal heat pumps / solar water heaters and/or some combination thereof?

I don't own a geothermal heat pump system, but a good friend of mine installed one in his new home. It was pricey, but he feels it was worth the investment. His home is about the same size as mine (both of us have 3,200 foot walk-out ranch style homes). His power bills are a little less than half what I pay. The system is whisper quiet which is pretty cool.

The bottom line: Warranty was 10 years on the system he purchased which was a big deal to him. You don't want to get stuck paying for major repairs on these systems. Including tax incentives, break-even on the investment should occur around year 6 (depending on what happens with energy prices). If you can afford it, AND you plan to stay put for 8+ years, a geothermal system appears to be a good idea.

[thefish7]

Thanks khanduit... is the heat pump able to handle the full heating and cooling needs of the house or is it supplemented by a traditional HVAC system? Does it maintain full effect during very hot and very cold weather?

[Da Coach]

You will need a backup system like a standard electric coil to generate heat on very cold days. Heat pump systems can't produce enough heat when temperatures drop into single digits or lower, unless you have the best insulated house in Peoria.


The air leaving the heat pump is only a couple degrees warmer than the cold air returning to it. That can work well when the outside temps aren't real low, but on very cold days, the pumps run continuously, blow air at high speeds to distribute it (since it is barely warmeer than room air) and they produce a lot of drafts. I know more than one person with a heat pump who installed and went back to a conventional gas furnace despite the savings a heat pump can give.

[thefish7]

DC, did your friend install a geothermal system or just a regular heat pump?

[Da Coach]

Both the people I am referring to had the common heat pump, not the geothermal system.

Do geothermal systems generate a much greater amount of heat?

[thefish7]

The literature seems to indicate so. "Regular" heat pumps just use the differences between the air and the house and so only work well in fairly moderate climates. Geothermal ones use the difference between the earth and house and at a certain depth the ground's temperature doesn't change much all year. It would seem the greater the difference between the house and whatever you're using to heat or cool the house allows for greater efficiency in the system. The geothermal systems, at least, can be used to generate both heat and cool.

Thing is, the geothermal systems use a heat pump kind of like any other, but you have to drill into the ground to put the tubes the heat pump circulates fluid through... so the heat pump is more expensive and you have to invest in the drilling. Most of the literature seems to indicate you can pay it off in about 6 years, but I'm basically curious to get some first hand experience to evaluate the literature against.