On 29 Mar, "Clive" wrote:

So you get the most hot water for heating on the sunniest days when
you are least likely to use it. I think you have it arse about face.
Use solar to augment the hot water which you will use year round.

MBQ

I see where you are coming from. Isn't that the conundrum with any
domestic solar-based heat / energy colleciton in the UK? The
conditions that will lead to "usable" heat from the panels will tend
to be those days when you don't need the space heating.

Its often brought up, but is not a problem in reality. The system is
sized to give useful heat for a sizeable amount of the year, and any
excess harvest in midsummer does not cause any real problems.


environment. I am sure there is an argument that the energy expended
in manufacturing, transporting and installing the equipment needed for
a "solar-supplemented" system far exceed any marginal savings in gas
burned.

I think thats true with systems that arent well designed. There are
many about that will never pay their way financially or energy wise.
To get one that does something useful one must properly evaluate the
proposed system first, and try design after design until one proves
good. It will be nice to see the day when this process is no longer
necesary, due to future leaps in performance and economy.


boiler). Now, the thermal store literature claims it can deliver
instant, *mains pressure* hot water. I can't understand *how* , since
it's just a cylinder - sorry, thermal store. Won't it need a head of
pressure i.e. loft installation to deliver hot water under pressure?
I'll take that on trust unless anyone can explain how the thermal
store system achieves the mains pressure output?

The hot water outlet connects to the incoming water mains. No header
tank is used. Hence its still at mains pressure. Its made hot along
its travel by going through a heat exchanger. The tanked hot water is
an entirely separate body of water that just heats the heat exchanger
plates.

The downside of this is fouling of the heat exchanger, hence the need
to use an exchanger with much higher power rating than will be needed
initially.


BTW, I have looked at that self-built heat-exchanger to reclaim heat
from shower waste and pre-heat the cold supply to the shower. Looks
really neat, simple to manufacture and plumb in - so seems surprising
it's not mass-produced.

Clive

Good question, why isnt it?

Its not fitted at new buid because its an unnecessary cost to the the
builder and house buyer, and isnt required by regs yet. Also few house
buyers even know about them so far.

Its not diy retrofitted because its too much upheaval/work for limited
gain.

So there isnt much of a market at present. With increasing drive to
get better energy efficiency I daresay they;ll become required some
time soon.


NT