Today's solar heat

No problem!

You're right - it's a very nice area

Don't worry about being from Norfolk - they're very broad-minded down here and let all sorts of people 'in'

I had a stand at an exhibition last Sunday - big notice on it saying 'Cheques welcome - also Hungarians, Australians and people from Norfolk'

Corny, I know - but it raised a few smiles.... !

Good luck with your solar Adrian Suffolk UK ======return email munged================= take out the papers and the trash to reply

Interesting, how does the system heat the water if there isn't a storage cylinder? I'm puzzled.

Jake

You could still support the Caneries, just don't shout to loud. Brian (another old Norfolk boy)

You getastoragecylinder.

They're not expensive :-)

Mary

"Mary Fisher" wrote in

They are if you haven't got the space ;-) I think there was also problems, amongst others, with access to a suitable roof. Instead they went for massive amounts of insulation well above current regulation standards.

Jake

who?

Mary

"Mary Fisher" wrote

They

HTH

Jake

I think the clue was in the bit where she said "heat the water in the cylinder for as long as you like"

i.e. they *do* have a cylinder. (just because you have a combi, it does not mean you can't also have a cylinder)

No

Oh, you mean he's not using the standard 1:3 normal - heavy water ratio? :)

well, it does improve capture with diffuse light, but not by anywhere near as much as with direct sun. Poor real world performance of concentrator systems in winter is down to their typically small collector areas.

There are times a concentrator will deliver heat when flat panels wont.

ok theres a proven system a bit like this using shade cloth. 2 or more layers of shade cloth, just one of glass. The air flow is from near the outer glass towards the inside, through the cloth, and efficiency is very high, far above any black or selective absorber system. And the cloth is cheap, unlike glass.

only above a point. Double glazing will give more power out than single, as conduction losses are less. Triple may not. Extending the dg layer below the first glazing layer also provides reduced heat loss.

: ___ : |___| : | | | : | | | : | | | : | | | : | | | : | | | : |_| | : | | : | | : |___| : :

in order from left to right: dots for text formatting roof/base of panel single glazing layer double glazing layer

The area below the panel captures heat that flows over the single glazing layer, reducing panel heat loss further.

this is what I've been thinking about for some time now. Each panel type performs best in different parts of the system. Eg vac tubes for the top of the tank, as theyre the only thing that performs sensibly at high temp, rads as a simple minimum cost inlet prewarmer, and flat panel for the bulk of tank heating.

still just as puzzled :)

NT

Interesting.

Adding another level of glazing will increase the maximum temperature it will reach at 0 flow. It will reduce the maximum power output at a reasonable flow to below the temperature without an extra pane, due to the lower power due to the losses from the first pane.

Ok, in more words :)

Instead of having a 1m^2 radiator, in a 1m^2 panel, you have a 0.5m^2 radiator in a 1m^2 panel, and a fan, to circulate the air to the radiator.

IIRC The solar barn uses it at

yes

I still am not seeing how you can conclude that, since an extra layer of glazing has 2 opposite effects, not just one. First there is 5% or so absorption reducing the power output, then there is the double glazing effect reducing convention losses, which increases power out.

ahh :) I dont think youd need a fan. Why dont you run this past alt.solar.thermal? Lots of expertise there. When I calculated something similar, small collector plus plenty of space yielded more than the small colelctor in small box but less than the bigger in the bigger box. I think small rads in bigger boxes would make good sense, long as youre not short on glass.

NT