On Feb 2, 4:14 pm, Roger Chapman wrote:
Tim Lamb wrote:

snip



600m seems a lot. Is that the normal sort of length for a ground
loop and (without the well) how much land would be needed?
a lot depends on the soil. dry sandy is crap, wet soggy clay is very
good. I was quoted 200-400m in clay, no loop within 2 meters of any
other, for 12kw peak.
so 400 square meters minimum, for me, 800 squares better.

0.1 to 0.2 of an acre seems to give me a better idea of the size.
Should fit in some (but by no means all) back gardens but installation
would make a complete mess of said garden even if it is practicable to
dig the trenches at 2 metre centres. If I ever get round to it I might
consider the adjacent field instead but that could bring its own
problems.

If I ever get round to GSHP using buried pipe I will try to *mole* it in
rather than trench. Subsoils here are clays and gravel and I have pulled
50m lengths of blue poly for water supplies without problems. I like the
manifold idea as pulling loops with more than two legs would be
difficult. Luckily the *moles* will fill with water so there is no lack
of contact.

IIRC moles can't get down to the sort of depth really needed for heat
pumping but I would be glad to be proved wrong even though the back lift
on my neighbours tractor doesn't work properly so I would have to hire
the equipment to do it.

On a connected topic there is a particular form of plough used to make a
form of land drain. Can anyone tell me what it is called please. We have
a very boggy hollow that really needs draining presumably because the
land drain has collapsed. I can't find the actually drain but even if I
could I lack the resolve to dig out and rebuild what might be as much as
100 yards of drain having spent a couple of weeks last Autumn on a
section less than 15 yards long.

are you trying to actually create a drain with this plough? or break
up the so called "pan" between subsoil and topsoil with a "subsoiler"
plough?

Cheers
Jim