"Andy Champ" wrote in message
...
David Hansen wrote:
On Fri, 29 Feb 2008 21:17:32 +0000 someone who may be Andy Champ
wrote this:-

Twin coil? So there are two indirect coils?

Two or three coils, depending on the number of heat sources. More
than three becomes interesting.

http://www.newarkcyl.freeserve.co.uk/solar%20page.html gives some
(external) photographs and a drawing.


Ah I see. But how long before the finned coils scale up?

Doesn't that mean there isn't much room for hot water above the boiler
fed (presumably hotter) coil?

If sized correctly there is enough room above the boiler coil.

This arrangement also has the advantage that solar can heat the
whole cylinder and thus store more heat.


Gotcha. It'd work for me, I have a full height airing cupboard, and it's
a better than 2 cylinders.

I'm still far from convinced it's cost effective at current prices. (And
the best thing I could do for the environment would be in transport, not
heating)

Do both. And more.

Mary

Andy