Yes. I do know there are umpteen thousand hits on the web!

How many kW would be needed to space heat 200m2 of single storey offices
meeting current building regs. but only 4 to 5m wide (lots of outside
wall and roof)?

How much useful heat could I extract from pumped groundwater within the
current *no licence* abstraction limit of 20m3/day?

regards
--
Tim Lamb

On Jul 15, 12:49*pm, Tim Lamb wrote:
Yes. I do know there are umpteen thousand hits on the web!

How many kW would be needed to space heat 200m2 of single storey offices
meeting current building regs. but only 4 to 5m wide (lots of outside
wall and roof)?

How much useful heat could I extract from pumped groundwater within the
current *no licence* abstraction limit of 20m3/day?

regards


R measures insulation, U measures conductance
U value is thermal conductance in W/m^2k
(watts, metres square, kelvin)

R value = 1/ U value


Normally with GSH one doesn't abstract any water, one just takes the
heat from the water.


NT

"NT" wrote in message
...

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

On Jul 15, 1:56*pm, "BruceB" wrote:
"NT" wrote in message
....

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.

A

wrote in message
...
On Jul 15, 1:56 pm, "BruceB" wrote:
"NT" wrote in message
...

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.

Regards
Bruce

"BruceB" wrote in message
.. .

wrote in message
...
On Jul 15, 1:56 pm, "BruceB" wrote:
"NT" wrote in message
...

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

wrote in message
...
On Jul 15, 1:56 pm, "BruceB" wrote:
"NT" wrote in message
...

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.


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.

"BruceB" wrote in message
.. .

"NT" wrote in message
...

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

He said that 20m3 a days needs no licence.

On Jul 15, 1:56*pm, "BruceB" wrote:
"NT" wrote in message
....

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

It can be done that way, or the well water can simply be left where it
is and heat harvested from it by conduction/convection


NT

NT wrote:
On Jul 15, 1:56 pm, "BruceB" wrote:
"NT" wrote in message
...
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

It can be done that way, or the well water can simply be left where it
is and heat harvested from it by conduction/convection



I think you have a basic misconception.

Ground source heat pumps that use water as a heatt reservoir take the
heat, not the water. The primary curcuit is antifreeze loaded water in a
closed loop.

That loop is generally buried in the ground, but it can be laid at the
bottom of a pond.


NT

On Jul 15, 12:49*pm, Tim Lamb wrote:
Yes. I do know there are umpteen thousand hits on the web!

How many kW would be needed to space heat 200m2 of single storey offices

Which 200m2 are you heating, at the floor or at the ceiling or
somewhere in between?

MBQ

Man at B&Q wrote:
On Jul 15, 12:49 pm, Tim Lamb wrote:
Yes. I do know there are umpteen thousand hits on the web!

How many kW would be needed to space heat 200m2 of single storey offices

Which 200m2 are you heating, at the floor or at the ceiling or
somewhere in between?


If the building is square, its about 14 meters square.

If its say 3 metres high, the total area external to the world is
200 sq meters of roof and 4x16x3 meters of wall

say 400 square meters in all.

I've ignored the floor here. If you feel its important add another 200
and make it to 600 sq meters worst case. That will just about cover the
'long thin' building. Presumably UFH is in the frame with a heat pump,
so teh floor will be well insulated..

No with a U value of about 1 for reasonable insulation, that's about
600W per degree centigrade differential, and with say 25 degrees
absolute worst case in winter, that's a total of 15KW.

However by my reckoning the average person in an office is around 200W
of human heat, PCs etc and lighting and about 20 people minimum will be
in that office, so its likely to only need around 9KW. Worst case. With
about 3:1 upscale on the heat pump, about 3Kw electricity with a good
ground source pump.




MBQ

In message , The Natural Philosopher
writes
Man at B&Q wrote:
On Jul 15, 12:49 pm, Tim Lamb wrote:
Yes. I do know there are umpteen thousand hits on the web!

How many kW would be needed to space heat 200m2 of single storey offices
Which 200m2 are you heating, at the floor or at the ceiling or
somewhere in between?


If the building is square, its about 14 meters square.

If its say 3 metres high, the total area external to the world is
200 sq meters of roof and 4x16x3 meters of wall

say 400 square meters in all.

I've ignored the floor here. If you feel its important add another 200
and make it to 600 sq meters worst case. That will just about cover the
'long thin' building. Presumably UFH is in the frame with a heat pump,
so teh floor will be well insulated..

No with a U value of about 1 for reasonable insulation, that's about
600W per degree centigrade differential, and with say 25 degrees
absolute worst case in winter, that's a total of 15KW.

Target U value figures are 0.35 for walls, 0.25 for floor, 0.2 for roof
and 2.2 for windows.

However by my reckoning the average person in an office is around 200W
of human heat, PCs etc and lighting and about 20 people minimum will be
in that office, so its likely to only need around 9KW. Worst case. With
about 3:1 upscale on the heat pump, about 3Kw electricity with a good
ground source pump.

I thought the allowance is 60W per person? I would expect occupancy to
be less than 10. Toilets, stairwell, kitchenette, reception etc.

regards




MBQ

--
Tim Lamb

Tim Lamb wrote:
In message , The Natural Philosopher
writes
Man at B&Q wrote:
On Jul 15, 12:49 pm, Tim Lamb wrote:
Yes. I do know there are umpteen thousand hits on the web!

How many kW would be needed to space heat 200m2 of single storey
offices
Which 200m2 are you heating, at the floor or at the ceiling or
somewhere in between?


If the building is square, its about 14 meters square.

If its say 3 metres high, the total area external to the world is
200 sq meters of roof and 4x16x3 meters of wall

say 400 square meters in all.

I've ignored the floor here. If you feel its important add another 200
and make it to 600 sq meters worst case. That will just about cover
the 'long thin' building. Presumably UFH is in the frame with a heat
pump, so teh floor will be well insulated..

No with a U value of about 1 for reasonable insulation, that's about
600W per degree centigrade differential, and with say 25 degrees
absolute worst case in winter, that's a total of 15KW.

Target U value figures are 0.35 for walls, 0.25 for floor, 0.2 for roof
and 2.2 for windows.

That's good. Experience suggest with windows and adequate ventilation
that WILL average out to about 1.,.


However by my reckoning the average person in an office is around 200W
of human heat, PCs etc and lighting and about 20 people minimum will
be in that office, so its likely to only need around 9KW. Worst case.
With about 3:1 upscale on the heat pump, about 3Kw electricity with a
good ground source pump.

I thought the allowance is 60W per person? I would expect occupancy to
be less than 10. Toilets, stairwell, kitchenette, reception etc.

60W for the person, and a further 140W of lighting, and general
equipment is my reckoning. Making cups of coffee, strip lighting, PC,
shared printer, router PABX etc etc etc.

In winter, lights tend to be on most of the day.

I am trying to quickly calculate what square meterage I have here..18x7
+ 10x6.. thats 186 sq meters, twice for two storeys. I need according
to the heating engineers report, 10KW worst case. Similar U values. My
12KW boiler JUST copes in worst winter conditions. has to be on 24x7,
but it does the job.

I did some ground source heatpump calcs, and they reckoned a hard wired
unit with soft start on a single phase could just do the job, with a
ground loop of around 400 meters length in wet clay.




I've got an acre or so to play with, so that's not a problem. The
problem was the heating tank (which could be just immersion using the
heat pump as a preheater) and the upstairs, which is small bore rads and
fan convectors that need at least 65C to even start fanning - thermostat
switches.

Essentially all that would need replacing. BIG job. Then oil came down
in price and I shelved the idea.

How much land have you got to work with?

In message , The Natural Philosopher
writes

I did some ground source heatpump calcs, and they reckoned a hard wired
unit with soft start on a single phase could just do the job, with a
ground loop of around 400 meters length in wet clay.







I've got an acre or so to play with, so that's not a problem. The
problem was the heating tank (which could be just immersion using the
heat pump as a preheater) and the upstairs, which is small bore rads
and fan convectors that need at least 65C to even start fanning -
thermostat switches.

Essentially all that would need replacing. BIG job. Then oil came down
in price and I shelved the idea.

How much land have you got to work with?

About 90 acres:-)

Realistically one would only lock up land which had no prospect of other
development or sale.

The bit I am considering is a 1/4 acre strip bordering the river. Mean
water table is around 18" (higher in the winter) so wet!

If I can't get anywhere with the EA I can clean out an existing cress
ditch which is parallel to the river, about 7m wide and 75 long.

Space heating can be underfloor throughout and I can use a gas combi for
washing etc.

I imagine there might be some *economy of scale* using one industrial
size plant rather than several domestic units.

regards

--
Tim Lamb

In message
, Man
at B&Q writes
On Jul 15, 12:49*pm, Tim Lamb wrote:
Yes. I do know there are umpteen thousand hits on the web!

How many kW would be needed to space heat 200m2 of single storey offices

Which 200m2 are you heating, at the floor or at the ceiling or
somewhere in between?

Floor. Unfortunately the existing layout leads to rather a lot of
external wall:-)

regards

--
Tim Lamb