Roger Chapman wrote:
JimK wrote:
On Feb 2, 12:56 pm, "dennis@home"
wrote:
Given that the average air temp in the UK appears similar to the
ground temp
how much extra does a GSHP save over an ASHP? I was toying with the
idea but
I would need a bore hole for a GSHP and they are not cheap. Also as
the heat
for the GSHP is actually solar there must be a problem replacing the
heat in
the bore hole if the neighbours also decide to drill them, there isn't
enough land in the cities to absorbed the solar radiation needed.

Ground temperatures are much more even than air temperatures and the
deeper you go the more constant the temperature.

so are you saying the deeper you drill the colder it gets?

The deeper you go the warmer it gets but ISTR TNT saying here quite
recently that the major source of near surface heating is solar.

It is..but even so in winter, the deeper the warmer. Average UK temps
and that reflects the subsoil, are about 9C.

Go deep enough and thats what you find.

Hence the need for a s deep a pipe run as is practicable with a digger.

Generally a couple of meters max.