Geothermal well

bally2009

Planning going through at the moment for a 2200sqft house. Exploring some ideas for heating the house. There's a recently disused domestic water well circa 90m from the house. This could be a naive question. Could this potentially be used as a ground source for geothermal? Would there be costs saved by this process?

The Continental Op

I know of it being done but afaik it all depends on the yield of the well. In the one I know of water is pumped out of the well which taps an underground aquafer. I don't think that would work with a static low yield domestic water well.

Water John

Yes, it could. You can get a quite high COP 5/6:1. You need 3 cu metres per hour. Crowd in Galway does them I think. Google water to water heat pump. You tend to need a second borehole to take the discharge water.

The Continental Op

https://www.boards.ie/discussion/comment/120449508#Comment_120449508

Thats only 3000 litres of water but as most households would use a less than a 1000 litres a day a household well might not hold up. At the very least it needs pumping at that rate during a dry spell in the summer to test it.

graememk

If you need another hole to discharge into, prob easier to get a borehole for geo thermal?

Water John

The second hole doesn't need to be very deep. Yes, you'd want to be living in an area with good underground water supply. I think it's an option that should be looked into more by rural people. Though if the house is a high BER the difference to A2W may not be worth the extra cost. Put your resources into achieving a high BER, including mechanical heat recovery ventilation.

bally2009

Thanks for the comments of advice. Good to know that it could be an option