Solar Hot Water and Heatbanks

message from Vortex on 13 May 2004

Hi,

Later this year I will be installing a heatbank (see www.heatweb.com if you
don't know what I'm on about) in my home. It will replace my indirect hot
water cylinder.

I also intend to have a "secondary solar loop" in the heatbank so I can
experiment with solar panels....because I have a south facing pitch on my
roof I reckon I can potentially enjoy solar hot water - most of the time -
for half the year.

I want to understand the practicality and costs associated with using
"vacuum heat collecting tube" based solar panels. (This web site says a lot
more http://www.consolchinese.com/old/english/sun01.htm ).

Despite extensive Googling I have not been able to find objective technical
and pricing information for self-install solar panels in the UK.

I have numerous questions such as:

* What is the typical heat output/square metre in various weather
conditions.
* Is it normal to use pressurised operation (as in unvented CH)?
* What happens if things overheat? I don't think I want my heatbank to
boil.
* Do these things deliver usable energy on sunny Winter days?
* What should I expect to pay?

Any pointers? Any recommendations? Anyone done this?

BTW I've already calculated that I'm unlikely to get payback (ie fuel
savings paying for my efforts) in a realistic timeframe. This is actually
an excercise in self-gratification....and me doing my little bit towards the
Kyoto climate change treaty.

David

IMM replied to Vortex on 13 May 2004

Good choice.

These are expensive. Simple flat plate are a lot cheaper. You can make
them yourself. CAT at http;//www.cat.org.uk, sell a flat plate kit and
instructions.

How about making all the roof a collector. Then you will have a plenty of
hot water delivered. If you have a large roof a lot of flat plates can
return more hot water than a few vacuum tube panels.

Can be open vented. Many have self draining panels, that drain into a small
tank when there is no sun.

You have high temp cuts offs that switch off the pump. The heat bank will
its own safety devices anyway, if the panel safety devices fail.

All energy is usable and its is for nothing. On winters days the temperature
received are low.

If the CH is run from the heat bank, the panels will supplement the CH also
in winter. A full south facing roof can provide enough heat in winter to
run low temperature underfloor heating for much of the time. They are an
ideal match.

Archived message: Solar Hot Water and Heatbanks (UK D-I-Y House Decoration)