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Old 04-29-15, 11:00 AM   #3
AC_Hacker
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Quote:
Originally Posted by MEMPHIS91 View Post
...My idea is to use an electric hot water heater with the HX coil from a window AC unit coiled inside, with the DX line running 30 feet deep into a 2 inch bore hole...
Jake,

Regarding the vertical bore hole and the lubricant issue, when I cited it as a potential problem, I was acting as a 'devil's advocate', and was (am) trying to visualize possible problems. I was not saying that a 30 ft deep DX hole will not work... it might work just fine.

We have heard from other folks from MS here on EcoRenovator, and from all reports, making vertical boreholes is comparatively easy in MS, compared to some other parts of the country. So in that regard, nature has been very kind to you.

So, I guess what I'm trying to say is that I hope your project doesn't get tied up in knots over my comment about the possibility of lubricant starvation in a 30' vertical hole. Your initial vision is clear and good, and quite likely to work exactly as you originally envisioned it.

& & & & &

Having said all that, only if your vertical idea doesn't pan out, you might want to consider the illustration below:



This is a typical diagram of a DX loop field as it is often implemented commercially. I always thought that this method was used because it resulted in the minimum disturbance to a suburban landscape, which is a very common reason that many people do not want to do a GSHP installation, even knowing the much greater efficiency (my girlfriend being one of them).

But thinking about a potential lubrication issue, and remembering this diagram, I see that a horizontal borehole would give good exposure to the soil, and reduce the vertical vertical lift.

It would also be much harder to dig unless you had specialized diagonal digging equipment, as seen below:




& & & & &

Just in case you didn't see it already, I just came across a Wikipedia entry on DX heat pumps HERE that indicates that vertical DX boreholes have been drilled to depths as great as 100 ft. so do not be discouraged, do not be confused.

Push on!!

Best,

-AC
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