Quote:
Originally Posted by Littlebear
Hello BMW Experts!
I would love to do Ground loop heat exchange (geothermal) for a house in the hills I am looking at. Questions, questions, questions, though....
- I see this not recommended for little homes because of the drilling cost. How small of a house would this be practical for?
- Can the house be split into zones easily?
- What type of "soil" is best, and worst for drilling, and how do costs differ in, say, rock vs dirt?
-Anything else you can tell me about ground loop geothermal would be cool (Discuss!).
TIA! Murf
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I did some research into it and there are a lot of variables, you need to get a rough estimate of cost from someone in your area. Lot size, soil, estimated savings - do the calculations to figure out when you break even. Works best for larger houses as the initial cost doesn't change much (comparatively) from the smaller home but the utility savings can be double.
Biggest issue to me was the initial cost compared to how much it saves to how much it increases the houses value. Example - if you spend $20k initially, then save $1k per year on utilities and it raises your house value by $5k, figure out how long you realistically think you will be there and what kind of profit you turn. Putting out an extra $20k in year 1 and getting it all back in 15 years isn't breaking even because of the time value of money and what else you could have done with the money. Maybe it raises the house value more but savings per year is higher or lower.
With a small house and very efficient, well designed system, not sure zoning it makes a lot of sense. Then if you do zone it not seeing why geothermal compared to another forced air system makes any difference. Most conventional systems have an interior coil the gets warm or cold and air is forced from there to wherever you want it to go. Maybe I am wrong?
I think rocks or stone in the soil is a negative (depends on the extent), sure can't see why it would help things. Again, would ask someone local to give a rough estimate of cost.