"BruceB" wrote in message
.. .
wrote in message
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On Jul 15, 1:56 pm, "BruceB" wrote:
"NT" wrote in message
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Normally with GSH one doesn't abstract any water, one just takes the
heat from the water.
But sadly, the environment agency consider it 'abstraction' even if you
put
it back again. So is you put more than 20m3 a day of say river water
through your heat pump then you would need an abstraction licence.
Regards
Bruce
I thought with a GSH pump you don't even move the water - the heat
pump pipes are a sealed system pumping coolant round the pipes. The
coolant is warmed up as it passes through the pipes which are immersed
in the groundwater, and that heat is then extracted in the building.
That can't possibly count as abstraction of water. I may be wrong
about the mechanism though.
***********
You are right, but the term GSHP is often used loosely. Taking water from
a river I would normally call a water source heat pump. More accurately
perhaps, we are talking about the difference between an open circuit and
closed circuit collector.
I was really making the point that even if you put water back it is still
abstraction.
The most efficient are water sourced heat pumps. Pumping ground water
through a heat exchanger and back to ground can do the same thing.
Extracting heat from a running stream is by far the best. Water contains 4
time more heat per volume than earth.
You can have a plastic pipe run under the earth circled as in Heat Pump
slinkies. But to improve matters run this pipe through a collection of
large water cylinders or plastic barrels above ground. Extract heat via the
heap pump at the hottest part of this system the storage cylinders . A
normal water pump would pump heat from the ground via the slinkies 24/7 and
dumps it into the cylinders, then the heat pump extracts the heat when
needed from the cylinders. The heat from the surrounding air, heating the
water in the barrels has some gain too. The mass of water in the
cylinder/barrels hold 4 times more heat than earth, so acts as a
concentrator upping the heat efficiency.
This is a slinky for a ground sourced heat pump, made from a concrete block.
http://www.ebuild.co.uk/forums/messa...tml?1208929618