I was contemplating a project for a long time in the future, and
stumbled upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar
heated water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch
the SWesterly winds blowing up the Bristol channel see S.W. picture
he http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the
heat bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit
happening when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be
sorted first, I thought I needed to get some thought on the idea before
I waste more time on theoretical pipe runs and Mast locations etc.
:¬)

Cheers
Pete
--
http://gymratz.co.uk - Best Gym Equipment & Bodybuilding Supplements UK.
http://trade-price-supplements.co.uk - TRADE PRICED SUPPLEMENTS for ALL!
http://fitness-equipment-uk.com - UK's No.1 Fitness Equipment Suppliers.
http://Water-Rower.co.uk - Worlds best prices on the Worlds best Rower.

""Pet @ www.gymratz.co.uk ;¬)"" schrieb im
Newsbeitrag . uk...
I was contemplating a project for a long time in the future, and stumbled
upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar heated
water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch the
SWesterly winds blowing up the Bristol channel see S.W. picture he
http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the heat
bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit happening
when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?

Shure and very easy.

It's not modern to have the DHW in a boiler.

Solar and heat pump systems loose efficiency at high temperatures,
but temperatures between 40 and 60 Celsius love Legionella
to breed.

So the solution is to have a closed loop storage for hot water
The DHW is warmed up by a plate heat exchanger

http://live.pege.org/2005-photovoltaic/warm-water.htm

All this with a heat pump combined and with
photovoltaic / heat combinded system


--
Roland Mösl
http://car.pege.org cars and traffic
http://live.pege.org building and live
http://www.pege.org

Roland Mösl wrote:

""Pet @ www.gymratz.co.uk ;¬)"" schrieb im
Newsbeitrag . uk...
I was contemplating a project for a long time in the future, and
stumbled upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to
reduce/eliminate required heat boiler input into DHW. Logical use of
this is a Solar heated water bank thing before the boiler. That's the
easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch
the SWesterly winds blowing up the Bristol channel see S.W. picture
he http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the
heat bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit
happening when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring
main as per usual method.

Can anyone see a possible flaw in my plan?

Shure and very easy.

It's not modern to have the DHW in a boiler.

Sadly, its not very green to not do it either.
DHW requirements are trivial compared with house heating requirements.
Well ours are.

Maybe we use 250litres of DHW a day.. raised by what/..40C? say 10
megajoule..3KWh? about 1Mwh per year, or about £130. Even on electric
heating, which it aint. Say £60 worth of oil..

The central heating spend is £1000 these days..spend a thousand or two
to heat hot water, or a thousand or two to knock 10% off the heating
bill..I know which I'd rather do...

Whats the energy payback of solar heating? Compared with energy to make
the units? Ditto windmills.

Once the BCO has gone I am going to block up half to three quarters of
the roof ventilation and the underfloor ventilation. I reckon that will
save me £300 a year easy. Its a howling icy GALE up there in winter, and
under the ground floors as well.

Pet @ www.gymratz.co.uk ;¬) wrote:

I was contemplating a project for a long time in the future, and
stumbled upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar
heated water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch
the SWesterly winds blowing up the Bristol channel see S.W. picture
he http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the
heat bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit
happening when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be
sorted first, I thought I needed to get some thought on the idea before
I waste more time on theoretical pipe runs and Mast locations etc.
:¬)

Cheers
Pete


You can do things these ways if you wish, but in neither case will it
give you anything close to the best possible payback ie max energy
harvest from the equipment used. Solarthermal technology is at the
point today where it takes proper design effort to make a system that
can pay its way in the long term. Slap it together designs like this
just dont pay back.

Details:

First solar hw collector efficiency depends on water temp, the colder
the water being heated the more energy is harvested. So the idea is to
put them in the coolest part of the system where the output will be
useful. That means either heating the bottom of the hot tank /
heatbank, or running ufh, or using a solar preheat tank.

2nd windmill heating HW is using high price energy (electricity) to do
the job of low cost energy (oil & gas). This step alone divides your
payback by about 3.

3rdly, solar dhw just doesnt compare to solar space heating. Space
heating is much cheaper, more efficient, yields far more energy
payback, and costs in the region of a tenth the price to install. If
you want good payback, solar space heating is the way.

There are newsgroups with expertise on this stuff, alt.solar-thermal
and alt.solar.pv.


NT

""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
. uk...
I was contemplating a project for a long time in the future, and stumbled
upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar heated
water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch the
SWesterly winds blowing up the Bristol channel see S.W. picture he
http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the heat
bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit happening
when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be sorted
first, I thought I needed to get some thought on the idea before I waste
more time on theoretical pipe runs and Mast locations etc.
:¬)

Your Eco-Hometec (rebadged German MAN) is a combi version (DHW and instant
CH in one box) I assume. Roland seemed to be showing a heat bank - a
thermal store using a plate heat exchanger and pump for DHW take off for the
cylinder. Look at this web site for an explanation. http://www.heatweb.com

The Eco-Hometec cylinder is a normal unvented cylinder with a solar coil. It
needs to be fitted by an approved installer and cost around £60 to £100 per
year for an annual service. Any gain via solar or wind is negated by the
service charge, so a no. no.

Try a vented heat bank (variant of a thermal store using a DHW plate heat
exchanger) heated directly by the boiler (no heating coil in the cylinder).
Heat the cylinder via the CH section of the boiler. The wind turbine can
heat an electric immersion heater in the cylinder. Any solar can be via a
solar coil, or even directly into the cylinder using an auto drain down
system. This way any energy gained by wind or solar may be used for CH or
DHW, not just DHW. The CH circuit can be taken off the heat bank cylinder
using a Grundfoss Alpha auto variable speed pump.

The cold mains pipe goes through the DHW plate heat exchanger.

Now you have a redundant DHW instant section on the combi boiler. This can
be used for backup if the DHW pump fails on the heat bank, by inserting some
valves in the DHW cold mains supply by isolating the combi or the heat bank.

This is the best approach for you.

It's not modern to have the DHW in a boiler.

Sadly, its not very green to not do it either.
DHW requirements are trivial compared with house heating requirements.
Well ours are.

Maybe we use 250litres of DHW a day.. raised by what/..40C? say 10
megajoule..3KWh?

250 litres * 40 C * 1,16 Wh for 1 litre to warm 1C = 11,6 kWh

about 1Mwh per year

11,6 kWh per year * 365 = 4234

It's fascinating, that people oposing solar energy can not calulate

--
Roland Mösl
http://car.pege.org cars and traffic
http://live.pege.org building and live
http://www.pege.org

"Roland Mösl" wrote in message
...
It's not modern to have the DHW in a boiler.

Sadly, its not very green to not do it either.
DHW requirements are trivial compared with house heating requirements.
Well ours are.

Maybe we use 250litres of DHW a day.. raised by what/..40C? say 10
megajoule..3KWh?

250 litres * 40 C * 1,16 Wh for 1 litre to warm 1C = 11,6 kWh

about 1Mwh per year

11,6 kWh per year * 365 = 4234

It's fascinating, that people oposing solar energy can not calulate

He also lives in a poorly insulated house that is far too large and has a
bath of around 750 litres. The oil companies love him.

wrote in message
oups.com...
Pet @ www.gymratz.co.uk ;¬) wrote:

I was contemplating a project for a long time in the future, and
stumbled upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar
heated water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch
the SWesterly winds blowing up the Bristol channel see S.W. picture
he http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the
heat bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit
happening when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be
sorted first, I thought I needed to get some thought on the idea before
I waste more time on theoretical pipe runs and Mast locations etc.
:¬)

Cheers
Pete


You can do things these ways if you wish, but in neither case will it
give you anything close to the best possible payback ie max energy
harvest from the equipment used. Solarthermal technology is at the
point today where it takes proper design effort to make a system that
can pay its way in the long term. Slap it together designs like this
just dont pay back.

Details:

First solar hw collector efficiency depends on water temp, the colder
the water being heated the more energy is harvested. So the idea is to
put them in the coolest part of the system where the output will be
useful. That means either heating the bottom of the hot tank /
heatbank, or running ufh, or using a solar preheat tank.

2nd windmill heating HW is using high price energy (electricity) to do
the job of low cost energy (oil & gas). This step alone divides your
payback by about 3.

3rdly, solar dhw just doesnt compare to solar space heating. Space
heating is much cheaper, more efficient, yields far more energy
payback, and costs in the region of a tenth the price to install. If
you want good payback, solar space heating is the way.

There are newsgroups with expertise on this stuff, alt.solar-thermal
and alt.solar.pv.



It is best he does what I suggest.

Doctor Drivel wrote:
""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
. uk...
I was contemplating a project for a long time in the future, and stumbled
upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar heated
water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch the
SWesterly winds blowing up the Bristol channel see S.W. picture he
http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the heat
bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit happening
when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be sorted
first, I thought I needed to get some thought on the idea before I waste
more time on theoretical pipe runs and Mast locations etc.
:¬)

Your Eco-Hometec (rebadged German MAN) is a combi version (DHW and instant
CH in one box) I assume. Roland seemed to be showing a heat bank - a
thermal store using a plate heat exchanger and pump for DHW take off for the
cylinder. Look at this web site for an explanation. http://www.heatweb.com

The Eco-Hometec cylinder is a normal unvented cylinder with a solar coil. It
needs to be fitted by an approved installer and cost around £60 to £100 per
year for an annual service. Any gain via solar or wind is negated by the
service charge, so a no. no.

Try a vented heat bank (variant of a thermal store using a DHW plate heat
exchanger) heated directly by the boiler (no heating coil in the cylinder).
Heat the cylinder via the CH section of the boiler. The wind turbine can
heat an electric immersion heater in the cylinder. Any solar can be via a
solar coil, or even directly into the cylinder using an auto drain down
system. This way any energy gained by wind or solar may be used for CH or
DHW, not just DHW. The CH circuit can be taken off the heat bank cylinder
using a Grundfoss Alpha auto variable speed pump.

The cold mains pipe goes through the DHW plate heat exchanger.

Now you have a redundant DHW instant section on the combi boiler. This can
be used for backup if the DHW pump fails on the heat bank, by inserting some
valves in the DHW cold mains supply by isolating the combi or the heat bank.

This is the best approach for you.

You could make better use of the DHW part of the combi by feeding the
mains input to the boiler with the output from the plate heat
exchanger. The combi will boost the hot water temperature if the
thermal store is empty or not hot enough.

"Dave" wrote in message
ups.com...

Doctor Drivel wrote:
""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
. uk...
I was contemplating a project for a long time in the future, and stumbled
upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar
heated
water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch
the
SWesterly winds blowing up the Bristol channel see S.W. picture he
http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the
heat
bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit
happening
when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be
sorted
first, I thought I needed to get some thought on the idea before I waste
more time on theoretical pipe runs and Mast locations etc.
:¬)

Your Eco-Hometec (rebadged German MAN) is a combi version (DHW and instant
CH in one box) I assume. Roland seemed to be showing a heat bank - a
thermal store using a plate heat exchanger and pump for DHW take off for
the
cylinder. Look at this web site for an explanation. http://www.heatweb.com

The Eco-Hometec cylinder is a normal unvented cylinder with a solar coil.
It
needs to be fitted by an approved installer and cost around £60 to £100
per
year for an annual service. Any gain via solar or wind is negated by the
service charge, so a no. no.

Try a vented heat bank (variant of a thermal store using a DHW plate heat
exchanger) heated directly by the boiler (no heating coil in the
cylinder).
Heat the cylinder via the CH section of the boiler. The wind turbine can
heat an electric immersion heater in the cylinder. Any solar can be via a
solar coil, or even directly into the cylinder using an auto drain down
system. This way any energy gained by wind or solar may be used for CH or
DHW, not just DHW. The CH circuit can be taken off the heat bank cylinder
using a Grundfoss Alpha auto variable speed pump.

The cold mains pipe goes through the DHW plate heat exchanger.

Now you have a redundant DHW instant section on the combi boiler. This
can
be used for backup if the DHW pump fails on the heat bank, by inserting
some
valves in the DHW cold mains supply by isolating the combi or the heat
bank.

This is the best approach for you.

You could make better use of the DHW
part of the combi by feeding the mains
input to the boiler with the output from
the plate heat exchanger. The combi
will boost the hot water temperature if the
thermal store is empty or not hot enough.


Firstly the combi, being an on-demand DHW heater, will be restricted down to
a lower flowrate than what the plate heat exchanger can deliver, so you will
get less DHW flows. The plate heat exchanger sized up properly will produce
all the hot water you need. So, best use the integral combi DHW section as a
backup using valve to bring in. With a blending valve fitted on the flow and
return pipes from the boiler to the heat bank cylinder, the boiler will be
pumping hot water up to temperature, say 75C, into the top of the cylinder.
This 75C water is then pumped out to the DHW plate heat exchanger. In
effect the boiler acts as an on-demand instant water heater when one of
these blending valves are fitted.

This means you can downsize the cylinder size and combine the stored water
energy with the energy produced by the boiler via the burning gas. Have a
larger boiler, and the effect is that you have a very large on-demand water
heater supplemented by a buffer of stored hot water. So you can have:

1. Large cylinder and small boiler (boiler supplements the cylinder)

2. Small cylinder and large boiler (cylinder supplements the boiler)

You can either store energy in large hot cylinders, or use all the energy
available down a gas service pipe and little hot water storage. You can
even have two small boilers connected directly to the heat bank and have
backup if one boiler drops out.

Doctor Drivel wrote:
"Dave" wrote in message
ups.com...

Doctor Drivel wrote:
""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
. uk...
I was contemplating a project for a long time in the future, and stumbled
upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar
heated
water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch
the
SWesterly winds blowing up the Bristol channel see S.W. picture he
http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the
heat
bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit
happening
when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be
sorted
first, I thought I needed to get some thought on the idea before I waste
more time on theoretical pipe runs and Mast locations etc.
:¬)

Your Eco-Hometec (rebadged German MAN) is a combi version (DHW and instant
CH in one box) I assume. Roland seemed to be showing a heat bank - a
thermal store using a plate heat exchanger and pump for DHW take off for
the
cylinder. Look at this web site for an explanation. http://www.heatweb.com

The Eco-Hometec cylinder is a normal unvented cylinder with a solar coil.
It
needs to be fitted by an approved installer and cost around £60 to £100
per
year for an annual service. Any gain via solar or wind is negated by the
service charge, so a no. no.

Try a vented heat bank (variant of a thermal store using a DHW plate heat
exchanger) heated directly by the boiler (no heating coil in the
cylinder).
Heat the cylinder via the CH section of the boiler. The wind turbine can
heat an electric immersion heater in the cylinder. Any solar can be via a
solar coil, or even directly into the cylinder using an auto drain down
system. This way any energy gained by wind or solar may be used for CH or
DHW, not just DHW. The CH circuit can be taken off the heat bank cylinder
using a Grundfoss Alpha auto variable speed pump.

The cold mains pipe goes through the DHW plate heat exchanger.

Now you have a redundant DHW instant section on the combi boiler. This
can
be used for backup if the DHW pump fails on the heat bank, by inserting
some
valves in the DHW cold mains supply by isolating the combi or the heat
bank.

This is the best approach for you.

You could make better use of the DHW
part of the combi by feeding the mains
input to the boiler with the output from
the plate heat exchanger. The combi
will boost the hot water temperature if the
thermal store is empty or not hot enough.


Firstly the combi, being an on-demand DHW heater, will be restricted down to
a lower flowrate than what the plate heat exchanger can deliver, so you will
get less DHW flows. The plate heat exchanger sized up properly will produce
all the hot water you need. So, best use the integral combi DHW section as a
backup using valve to bring in. With a blending valve fitted on the flow and
return pipes from the boiler to the heat bank cylinder, the boiler will be
pumping hot water up to temperature, say 75C, into the top of the cylinder.
This 75C water is then pumped out to the DHW plate heat exchanger. In
effect the boiler acts as an on-demand instant water heater when one of
these blending valves are fitted.

This means you can downsize the cylinder size and combine the stored water
energy with the energy produced by the boiler via the burning gas. Have a
larger boiler, and the effect is that you have a very large on-demand water
heater supplemented by a buffer of stored hot water. So you can have:

1. Large cylinder and small boiler (boiler supplements the cylinder)

2. Small cylinder and large boiler (cylinder supplements the boiler)

You can either store energy in large hot cylinders, or use all the energy
available down a gas service pipe and little hot water storage. You can
even have two small boilers connected directly to the heat bank and have
backup if one boiler drops out.

The O.P. did not mention any need to increase DHW flow. If the combi
flow is poor get a new one or just remove the restrictor.

Keeping the thermal store cool (by not heating with the boiler) will
maximise the solar heat input.

Dave wrote:

The O.P. did not mention any need to increase DHW flow. If the combi
flow is poor get a new one or just remove the restrictor.

Keeping the thermal store cool (by not heating with the boiler) will
maximise the solar heat input.

Exactly.

--
http://gymratz.co.uk - Best Gym Equipment & Bodybuilding Supplements UK.
http://trade-price-supplements.co.uk - TRADE PRICED SUPPLEMENTS for ALL!
http://fitness-equipment-uk.com - UK's No.1 Fitness Equipment Suppliers.
http://Water-Rower.co.uk - Worlds best prices on the Worlds best Rower.

wrote:


First solar hw collector efficiency depends on water temp, the colder
the water being heated the more energy is harvested. So the idea is to
put them in the coolest part of the system where the output will be
useful. That means either heating the bottom of the hot tank /
heatbank, or running ufh, or using a solar preheat tank.

That's what I suggested... a Solar pre-heat tank.

2nd windmill heating HW is using high price energy (electricity) to do
the job of low cost energy (oil & gas). This step alone divides your
payback by about 3.

I know this, but, as I wouldn't be able to get a big enough mill (6KW)
on the space available (or planning) I can't realistically export
surplus energy to the grid, so when energy is being produced during
times of minimum power consumption (all hours outside 07:00 to 09:00 and
17:00 to 23:00) so about 16 hours of the day, I thought it better to
initially use electricity to "top-up" heat-bank (Water pre-heater)before
switching to ring main feed.

Of course, if I get a few PC's and servers running then I doubt I would
over produce anything anyway.

3rdly, solar dhw just doesnt compare to solar space heating. Space
heating is much cheaper, more efficient, yields far more energy
payback, and costs in the region of a tenth the price to install. If
you want good payback, solar space heating is the way.

But our South facing wall has a big window across it which I'd prefer to
keep!

And... the sun is a bit arse about face when it comes to space heating
requirements.

:¬)


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Doctor Drivel wrote:

Try a vented heat bank (variant of a thermal store using a DHW plate
heat exchanger) heated directly by the boiler (no heating coil in the
cylinder). Heat the cylinder via the CH section of the boiler.

Doesn't this negate the benefits of the condensing aspect of the boiler
though?

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"Dave" wrote in message
oups.com...

Doctor Drivel wrote:
"Dave" wrote in message
ups.com...

Doctor Drivel wrote:
""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
. uk...
I was contemplating a project for a long time in the future, and
stumbled
upon an idea...

Our boiler MAN (ecohometec) can use pre-heated water to
reduce/eliminate
required heat boiler input into DHW. Logical use of this is a Solar
heated
water bank thing before the boiler. That's the easy bit.
Next idea was on Wind power. Our home is in an ideal location to catch
the
SWesterly winds blowing up the Bristol channel see S.W. picture he
http://www.gymratz.co.uk/pete/sunset1.jpg

So, assuming I could get planning to erect a 2.5KW turbine, the ideal
scenario would be have the turbine feeding an immersion heater in the
heat
bank (something like the following:
http://www.eco-hometec.co.uk/solar_cylinders2.html
So Solar by summer and wind by winter, but with the magical bit
happening
when heatbank/store is satisfied....

Electricity being switched by tank thermostat and divered into ring
main
as per usual method.

Can anyone see a possible flaw in my plan?
Currently we wouldn't be go the solar route as we only have East/West
sloping roof but that can be sorted with a future flat roof
replacement
over the garage.

As it is, it's a "hmmmmm....." plan with much smaller things to be
sorted
first, I thought I needed to get some thought on the idea before I
waste
more time on theoretical pipe runs and Mast locations etc.
:¬)

Your Eco-Hometec (rebadged German MAN) is a combi version (DHW and
instant
CH in one box) I assume. Roland seemed to be showing a heat bank - a
thermal store using a plate heat exchanger and pump for DHW take off for
the
cylinder. Look at this web site for an explanation.
http://www.heatweb.com

The Eco-Hometec cylinder is a normal unvented cylinder with a solar
coil.
It
needs to be fitted by an approved installer and cost around £60 to £100
per
year for an annual service. Any gain via solar or wind is negated by
the
service charge, so a no. no.

Try a vented heat bank (variant of a thermal store using a DHW plate
heat
exchanger) heated directly by the boiler (no heating coil in the
cylinder).
Heat the cylinder via the CH section of the boiler. The wind turbine
can
heat an electric immersion heater in the cylinder. Any solar can be via
a
solar coil, or even directly into the cylinder using an auto drain down
system. This way any energy gained by wind or solar may be used for CH
or
DHW, not just DHW. The CH circuit can be taken off the heat bank
cylinder
using a Grundfoss Alpha auto variable speed pump.

The cold mains pipe goes through the DHW plate heat exchanger.

Now you have a redundant DHW instant section on the combi boiler. This
can
be used for backup if the DHW pump fails on the heat bank, by inserting
some
valves in the DHW cold mains supply by isolating the combi or the heat
bank.

This is the best approach for you.

You could make better use of the DHW
part of the combi by feeding the mains
input to the boiler with the output from
the plate heat exchanger. The combi
will boost the hot water temperature if the
thermal store is empty or not hot enough.


Firstly the combi, being an on-demand DHW heater, will be restricted down
to
a lower flowrate than what the plate heat exchanger can deliver, so you
will
get less DHW flows. The plate heat exchanger sized up properly will
produce
all the hot water you need. So, best use the integral combi DHW section as
a
backup using valve to bring in. With a blending valve fitted on the flow
and
return pipes from the boiler to the heat bank cylinder, the boiler will be
pumping hot water up to temperature, say 75C, into the top of the
cylinder.
This 75C water is then pumped out to the DHW plate heat exchanger. In
effect the boiler acts as an on-demand instant water heater when one of
these blending valves are fitted.

This means you can downsize the cylinder size and combine the stored water
energy with the energy produced by the boiler via the burning gas. Have a
larger boiler, and the effect is that you have a very large on-demand
water
heater supplemented by a buffer of stored hot water. So you can have:

1. Large cylinder and small boiler (boiler supplements the cylinder)

2. Small cylinder and large boiler (cylinder supplements the boiler)

You can either store energy in large hot cylinders, or use all the energy
available down a gas service pipe and little hot water storage. You can
even have two small boilers connected directly to the heat bank and have
backup if one boiler drops out.

The O.P. did not mention any need to increase
DHW flow.

You don't suffer low water flows when you can have high flows easily.

If the combi flow is poor get a new one or just remove the restrictor.

Have you seen the price of a MAN? No need to get rid of the combi at all.
The DHW section can be made redundant and the heating side just heat up the
heat banks cylinder. It is only fit for backup.

Keeping the thermal store cool (by
not heating with the boiler) will
maximise the solar heat input.

You heat the cylinder right at the bottom where it is coolest. You design
the system so that DHW and CH returns are always cool back into the cylinder
to promote more effective solar and promoting cooler return condensing
efficiency.

""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
. uk...
Dave wrote:

The O.P. did not mention any need to increase DHW flow. If the combi
flow is poor get a new one or just remove the restrictor.

Keeping the thermal store cool (by not heating with the boiler) will
maximise the solar heat input.

Exactly.

See above.

""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
. uk...
Doctor Drivel wrote:

Try a vented heat bank (variant of a thermal store using a DHW plate heat
exchanger) heated directly by the boiler (no heating coil in the
cylinder). Heat the cylinder via the CH section of the boiler.

Doesn't this negate the benefits of the condensing aspect of the boiler
though?

Not at all. The body of water in the cylinder stratifies and leaves only
cool water at the bottom, which is returned to the boiler for more efficient
boiler operation. The body of water in the cylinder runs though the boiler,
not via a coil.

Pet @ www.gymratz.co.uk ;¬) wrote:
wrote:

First solar hw collector efficiency depends on water temp, the colder
the water being heated the more energy is harvested. So the idea is to
put them in the coolest part of the system where the output will be
useful. That means either heating the bottom of the hot tank /
heatbank, or running ufh, or using a solar preheat tank.

That's what I suggested... a Solar pre-heat tank.

Right. Next then comes the question of matching the collector
technology to the app. Flat panels are best for preheating, not vac
tubes. Flat panels with added concentration work better and more in
winter as well. If you want some vac tubes as well, I'd use those on a
separate circuit to heat the main hw tank or heatbank, as theyre best
suited to heating high temp water.


2nd windmill heating HW is using high price energy (electricity) to do
the job of low cost energy (oil & gas). This step alone divides your
payback by about 3.

I know this, but, as I wouldn't be able to get a big enough mill (6KW)
on the space available (or planning) I can't realistically export
surplus energy to the grid, so when energy is being produced during
times of minimum power consumption (all hours outside 07:00 to 09:00 and
17:00 to 23:00) so about 16 hours of the day, I thought it better to
initially use electricity to "top-up" heat-bank (Water pre-heater)before
switching to ring main feed.

Of course, if I get a few PC's and servers running then I doubt I would
over produce anything anyway.

Yes, its one problem generating it, then another problem setting up a a
system to make use of it. A windmill would not be very high on my list
of alt nrg choices.


3rdly, solar dhw just doesnt compare to solar space heating. Space
heating is much cheaper, more efficient, yields far more energy
payback, and costs in the region of a tenth the price to install. If
you want good payback, solar space heating is the way.

But our South facing wall has a big window across it which I'd prefer to
keep!

And... the sun is a bit arse about face when it comes to space heating
requirements.

So dont put it on the house. It can be on a fence, freestanding, or on
an outbuilding. This is by far the best option if you have some space
to put such a system in. An insulated air duct to the house is not a
big barrier.


NT

Doctor Drivel wrote:

Doesn't this negate the benefits of the condensing aspect of the
boiler though?

Not at all. The body of water in the cylinder stratifies and leaves only
cool water at the bottom, which is returned to the boiler for more
efficient boiler operation. The body of water in the cylinder runs
though the boiler, not via a coil.

Ah... I was presuming it went through a coil....

OK, if the hot from the boiler goes to the top of the tank and the
return from the bottom, then surely the turbulence of the pumped flow
would mess up any stratification. Our boiler modulates the pump to
ensure a 20 degree C difference. If the return was significantly lower
than the flow, presumably the boiler would ramp up the output to maximum
heat and pump speed until such difference was achieved. This would I'm
sure create a significant "mixing" of the water and again cause boiler
confusion and loss of any significant condensing benefit would it not?

--
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wrote:

So dont put it on the house. It can be on a fence, freestanding, or on
an outbuilding. This is by far the best option if you have some space
to put such a system in. An insulated air duct to the house is not a
big barrier.

But my theoretically "better half" would be.
:¬)

And it still only works best both in the seasons and the time of day you
don't require heat (if you work away from home), and you can't store
warm air for use later.
:¬(

--
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""Pet @ www.gymratz.co.uk ;¬)"" wrote in message
news
Doctor Drivel wrote:

Doesn't this negate the benefits of the condensing aspect of the boiler
though?

Not at all. The body of water in the cylinder stratifies and leaves only
cool water at the bottom, which is returned to the boiler for more
efficient boiler operation. The body of water in the cylinder runs though
the boiler, not via a coil.

Ah... I was presuming it went through a coil....

OK, if the hot from the boiler goes to the top of the tank and the return
from the bottom, then surely the turbulence of the pumped flow would mess
up any stratification.

Spreaders and diffusers take care of that inside the cylinders.

Our boiler modulates the pump to ensure a 20 degree C difference. If the
return was significantly lower than the flow, presumably the boiler would
ramp up the output to maximum heat and pump speed until such difference
was achieved.

No, it would probably lower the pump speed, to get the temp diff within 20C

This would I'm sure create a significant "mixing" of the water

Spreaders and diffusers take care of that inside the cylinders.

and again cause boiler confusion and loss of any significant condensing
benefit would it not?

Your boiler is quite sophisticated. I'm pretty certain you can change the
setting. It is set to operate directly on radiators, not heat a thermal
store cylinder. The makers would tell you the best setting.

As it is, if 25C water is returned to the boiler from the cylinder, the
boiler will only produce 45C temperature from the flow, and gradually
increase the flow temp as the return temp rises. Installing a blending valve
on the return between flow and return, blending water from the cylinder
return and flow from the boiler, set to say 55C (condensing temp), would
ensure that 75C water only ever enters the cylinder - the boiler sends hot
flow water back to the return to mix with cool cylinder water to raise the
return temperature.

Only having 75C water enter the top of the cylinder means that this water
can be used virtually instantly, or after a minute or so, for low flow DHW
purposes - a powerfull boiler mey be enough to supply one shower or more
(acting as a combi heating DHW on demand). The bottom of the cylinder will
eventually heat up past the 55C, and way above it. When the return temp
rises above 55C, to say 58C, 78C will be entering the top of the cylinder
(20C above), until either the cylinder is up to temp and/or the boiler cuts
off on highest temp setting which should be 82C.

Pet @ www.gymratz.co.uk ;¬) wrote:
wrote:

So dont put it on the house. It can be on a fence, freestanding, or on
an outbuilding. This is by far the best option if you have some space
to put such a system in. An insulated air duct to the house is not a
big barrier.

But my theoretically "better half" would be.
:¬)

And it still only works best both in the seasons and the time of day you
don't require heat (if you work away from home), and you can't store
warm air for use later.
:¬(


The basic system stores a lot of heat, and its not difficult to tweak
it so it stores a lot more. The fabric of the building, as long as its
brick or concrete, stores lots of heat. You then make it store more
heat by using a 'comfort zone.' This means that instead of a fixed
target temp you have a range, a comfort zone. In the afternoon you heat
it to the upper end of this zone to maximise the time until it drops to
the lower end of the zone.

Now if you put rubble in some of the collectors, and have 2 fans, one
for filled and one for empty collectors, you get one set with instant
heat output and another with storage. Note the storage temps are much
lower than electric storage heaters, so much more rubble is required.
The other way to do it is have an external heat store, fanning heated
air thru that when the fan supplying the house isnt on.


NT

On Tue, 12 Sep 2006 15:20:15 GMT, "Pet @ www.gymratz.co.uk ;¬)"
wrote:

Can you define a 2.5 KW turbine?

The message
from OldNick contains these words:

Can you define a 2.5 KW turbine?

Even a modest car alternator can do around a kW these days. I know
they're not ideal for wind turbine use, but it gives you an idea of
scale.

--
Skipweasel
Pay no attention to that man behind the curtain.

Guy King wrote:
The message
from OldNick contains these words:

Can you define a 2.5 KW turbine?

Even a modest car alternator can do around a kW these days. I know
they're not ideal for wind turbine use, but it gives you an idea of
scale.


Its not the size of the generator, its the size of the blades..to be
efficient in less than a hurricane, that genny is going to be a lot
bigger than a sky dish

Guy King wrote:

Can you define a 2.5 KW turbine?

http://www.provenenergy.co.uk/index....19&Itemi d=35

--
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On Fri, 15 Sep 2006 10:29:31 GMT, "Pet @ www.gymratz.co.uk ;¬)"
wrote:

Guy King wrote:

Can you define a 2.5 KW turbine?

http://www.provenenergy.co.uk/index....19&Itemi d=35

I'd love to know what a 600W telegraph pole is...

--
Frank Erskine
Sunderland

Frank Erskine wrote:

I'd love to know what a 600W telegraph pole is...

Smaller than a 2.5KW one I shouldn't wonder.
;¬)

--
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http://Water-Rower.co.uk - Worlds best prices on the Worlds best Rower.

OldNick wrote:

Can you define a 2.5 KW turbine?

A generator that mostly puts out a small fraction of 2.5kW.

NT

OldNick wrote:

On Tue, 12 Sep 2006 15:20:15 GMT, "Pet @ www.gymratz.co.uk ;¬)"
wrote:

Can you define a 2.5 KW turbine?

One that produces 2.5kW on a very windy day !

Graham

On Tue, 12 Sep 2006 15:20:15 GMT someone who may be "Pet @
www.gymratz.co.uk ;¬)" wrote this:-

Currently we wouldn't be go the solar route as we only have East/West
sloping roof

Others have given various opinions on the other bits of this. The
only thing to add is that East/West facing roofs are not a great
problem. One just uses two panels and an appropriate controller.
Evacuated tubes are much better in this sort of setup.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On Tue, 12 Sep 2006 15:20:15 GMT someone who may be "Pet @
www.gymratz.co.uk ;¬)" wrote this:-

Currently we wouldn't be go the solar route as we only have East/West
sloping roof

Others have given various opinions on the other bits of this. The
only thing to add is that East/West facing roofs are not a great
problem. One just uses two panels and an appropriate controller.
Evacuated tubes are much better in this sort of setup.

Putting panels/tubes on the wall is also a option, then maybe you'll
get a south facer. Putting kit anywhere but south facing is going to
kill the payback figures. Some people have put panels at ground level
too.


NT

On 17 Sep 2006 05:40:42 -0700 someone who may be
wrote this:-

Putting panels/tubes on the wall is also a option, then maybe you'll
get a south facer.

Indeed.

Putting kit anywhere but south facing is going to
kill the payback figures.

Assuming one evaluates the equipment just by simple payback figures.
Most people don't, otherwise replacement double glazing and
replacing a working boiler with a modern one would be rare indeed.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"David Hansen" wrote in message
...
On 17 Sep 2006 05:40:42 -0700 someone who may be
wrote this:-

Putting panels/tubes on the wall is also a option, then maybe you'll
get a south facer.

Indeed.

Putting kit anywhere but south facing is going to
kill the payback figures.

Assuming one evaluates the equipment just by simple payback figures.
Most people don't, otherwise replacement double glazing and
replacing a working boiler with a modern one would be rare indeed.

I think you should do your figures on replacing a boiler with a modern
condensing boiler. As gas prices has risen on one year by 25% the figures
are overwhelmingly in favour of a new boiler.

David Hansen wrote:
On 17 Sep 2006 05:40:42 -0700 someone who may be
wrote this:-

Putting kit anywhere but south facing is going to
kill the payback figures.

Assuming one evaluates the equipment just by simple payback figures.
Most people don't, otherwise replacement double glazing and
replacing a working boiler with a modern one would be rare indeed.

I realise some people dont work thru the numbers, but failing to do so
means getting a system that doesnt pay when you could have had one that
does. Payback equals energy return, and the whole purpose of solar tech
is energy return... so I'm not sure it makes much sense to design
blindly.

NT

On Sun, 17 Sep 2006 22:33:19 +0100 someone who may be "Doctor
Drivel" wrote this:-

I think you should do your figures on replacing a boiler with a modern
condensing boiler.

You are making the rather large assumption that I have not done so.

As gas prices has risen on one year by 25%

They have done, but it now looks like that was a one off. Indeed the
government customer group is already warning suppliers that it
expects them to reduce their prices in line with the reduction in
the cost of gas they buy.

the figures are overwhelmingly in favour of a new boiler.

As has already been discussed, one needs to allow for the parts that
will fail on a new boiler and thus counteract the savings the boiler
will make on gas. Then one has to look at the installation cost.

There are many reasons to replace an old boiler with a modern one
(and make the changes to the heating system to make it work
properly), but simple payback is not one of them.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 17 Sep 2006 15:18:32 -0700 someone who may be
wrote this:-

I realise some people dont work thru the numbers, but failing to do so
means getting a system that doesnt pay when you could have had one that
does. Payback equals energy return, and the whole purpose of solar tech
is energy return... so I'm not sure it makes much sense to design
blindly.

Blindly advocating a system designed for places like deserts, which
have warm days and cold nights, certainly doesn't make sense.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On 17 Sep 2006 15:18:32 -0700 someone who may be
wrote this:-

I realise some people dont work thru the numbers, but failing to do so
means getting a system that doesnt pay when you could have had one that
does. Payback equals energy return, and the whole purpose of solar tech
is energy return... so I'm not sure it makes much sense to design
blindly.

Blindly advocating a system designed for places like deserts, which
have warm days and cold nights, certainly doesn't make sense.

Not too sure how thats relevant here.


NT

Eeyore wrote:
OldNick wrote:

On Tue, 12 Sep 2006 15:20:15 GMT, "Pet @ www.gymratz.co.uk ;¬)"
wrote:

Can you define a 2.5 KW turbine?

One that produces 2.5kW on a very windy day !

Graham

Well, looking at the spec for the gennie he is talking about it
**claims** that it produces its 2.5kw for 5m/s wind, equivalent to
force 3, which is not a strong wind at all.

I looked into specs for wind gennies a couple of years ago when there
was a push on the 1 kw ones and they were specced for a force 6 which
is a strong wind and correspondingly less frequent. There are I
believe tables available that show how the wind force against days in
the year for most sites in the UK.

Rob

The message . com
from "robgraham" contains these words:

Well, looking at the spec for the gennie he is talking about it
**claims** that it produces its 2.5kw for 5m/s wind, equivalent to
force 3, which is not a strong wind at all.

Trouble is the energy available is related to the cube of the wind
speed. Drop from Force 3 to Force 2 and most of the output's gone.

--
Skipweasel
Pay no attention to that man behind the curtain.