On Jul 15, 7:33*pm, "Doctor Drivel" wrote:
"NT" wrote in message
...
On Jul 15, 4:51 pm, "Doctor Drivel" wrote:

This is a slinky for a ground sourced heat pump, made from a concrete
block.http://www.ebuild.co.uk/forums/messa...tml?1208929618

Interesting idea. But I think the assumption that the same amount of
heat will get extracted when all the pipes are bunched up close is
rather unrealistic. On the plus side the concrete used could contain a
high percentage of hardcore if the top of the cage is left open.


The concrete is poured onto the bedrock. Soil can be an insulator. *The
bedrock is not. There will be a constant movement of heat from the bedrock
to the concrete block. Concrete is a fair thermal conductor, at least
compared to dry soil. The *same with the bedrock that the concrete is
bonding to. So, the area that you scavenge heat from is greater than if you
were running through soil. *He's not scavenging from the soil above the
concrete "block". * If you were doing this in soil, you'd need a much much
larger contact area.

Interesting - but how many of us have bedrock 2m down?


In some buildings, concrete piles supporting buildings have plastic pipes
run in them for heat pumps to extract heat.

For the cost of some hardcore one can make a shallow underfloor void
to suck coolth from too. Only requires a fan and heat exchanger.


I would have the blue plastic the pipe in a figure of 8, so it crosses right
through the concrete block. *As it is, it is wound around the outside of the
concrete block.

that would cause it to freeze where it crosses, putting the system out
of action


If the water does not leave the ground - pumped
into a below ground chamber and out again, then
I would assume he can pump as much as he wants.

so much for assumption


He has not extracted from the ground any water. It all stayed under the
ground.

so much for assumption


NT