Good result Solar recharge of shallow field
 

BBF,

If you want to do this technique (above, last post), then ground heating will work. But for the majority of sites, a long vertical bore hole will encounter ground water and that literally washes away the heat as that flow migrates.

Sub-surface heat trapping does work as the prior article attests, but only under very specific conditions.

Heat storage will work well in vertically drilled rock (but have you priced the cost of drilling a 250 foot bore hole in rock?).

Steve

GSHP shallow loop:

I'm thinking of adding a 1000' loop of 1" HDPE outside basement (no underground joints). This would be pretty easy as excavation hole is 8' larger than basement on 3 sides, it's a walkout.

I'm getting 120ft2 more of used hot water solar panels cheap, total will be 360ft2, tank is 1000 gallons.

I should have excess solar heat every month to recharge this loop.

My water well fills to about 30' below surface, artesian effect.

I think that heating up the soil (decomposed granite gravel) around basement will lower the Delta-T through the basement ICF walls, which will lower heat loss below grade a bit.

Also in longer weather periods of poor solar gain, my Heat Pump may draw heat out of solar storage tank down to minimum (say 33*) and then Heat Pump can source from this loop.

Another system GEOSOL

ftp://ftp.aidea.org/Geothermal/geothermal%20solar.pdf

You might want to run the numbers on a 1000' loop (in your soil) being the heat source for a 24,000 BTU/hr heat pump.

The ground may (or may not) be able to yield up heat at the rate of 24,000 BTU/hr.

You'll never know until you run the numbers, or build it and wait for a prolonged winter cold snap to try it out.

-AC

I would like to run the numbers, but don't know where?

Looks strikingly similar to your proposed system. I wonder how (and if) the system is working a decade later. See? It can be done!

IGSHPA at Oklahoma State University has a large stock of the most relevant books on the subject of GSHP that you could ever need.

They are for sale and they aren't cheap, but some of our EcoRenovators have been able to snag copies for a song.

The relevant books would have tables and formulas for just about any situation imaginable.


I don't live in CO, I live in OR, Western OR. Around here, a 225 ft deep bore hole is expected to yield a Ton of heating. Where you are, I just don't have a clue.

A bore hole is a cylinder of earth going straight down and having a thermal radius of 16-ish feet (it tapers off continuously as you go farther from the center).

So what kind of cylinder will you have?

A lot of variables at play... your earth will be warmed (some).

Do you live on a hill? Shouldn't be much problem with water migration there.

Do you live on a hill side? Pretty certain there would be migration in that case, unless it is very arid.

There was an Irish guy that did something similar, on the forum... What happened to his post(s)?

-AC

Geothermal heat pump - Wikipedia, the free encyclopedia

"Recent studies show that utilization of a non-homogeneous soil profile with a layer of low conductive material above the ground pipes can help mitigate the adverse effects of shallow pipe burial depth. The intermediate blanket with lower conductivity than the surrounding soil profile demonstrated the potential to increase the energy extraction rates from the ground to as high as 17% for a cold climate and about 5-6% for a relatively moderate climate.[18]"

This is from:http://www.sciencedirect.com/science...17931012000671

House basement hole is dug into East facing hill, about 2:12 grade, top of hill is about 40' behind (West) of hole.

I have an area South of hole about 1500ft2 where slinky loop could be put in from 2' deep at East end to about 7' deep at West end, also could place pipe 4-8' from basement ICF on West & North sides (100')

Was reading on UK site where a professional GSHP installer runs solar heated water 100% through shallow loop in series with panels before HP.

Don't know if that makes sense?