Cistern for closed loop

[steve72]

I have an old cistern within 8 ft from the house that is roughly 6.5 to 7 feet in diameter and roughly 28-30 ft deep this cistern has not been used for years as the home has been on city water before i fill it in i was curious if i could get some use out of the hole by designing a closed loop system for secondary heat and cooling or even a pool heater system would there be enough volumn of earth to proporly disipitate the heat using a closed end coil system or some other idea , or should i fill it in?
Thanks.

[D-Allen]

Not a good idea. If it had fresh water running through it all the time it would work. Then you could go open loop.

[steve72]

Thanks,
what if we coiled the line around the perimeter and center then filled it in with fill dirt? which I plan on filling it in anyway just a thought>
Thanks again.

[D-Allen]

You would have to make sure you can even get enough loop in there to handle the load first. Then you have the concrete issue on heat transfer.

[steve72]

Thanks,
probably more trouble than its worth.

[SkyHeating]

Not a good idea. If it had fresh water running through it all the time it would work. Then you could go open loop.

+1 I worked with a homeowner who was going off the grid here in Portland Or and they were using a 10K Gallon cistern that brought it fresh rain water from the large roof area of the house. It ended up being to large of a task in this situation because there was no way to know how much water we were going to have or when the next set of fresh water was coming in(even though it does rain a lot in portland, it does not rain all the time)