"Andy Dingley" wrote in message
...
On 23 Nov 2005 17:32:26 -0800, wrote:

Why install an array of highly priced commercial
panels/tubes, [...]

Because a passive system really needs to be designed into the building
when it's built (or extended).

Because a flat panel system works well in wam weather but very badly in
cold sunny weather. It may still capture plenty of solar heat, but it
also has losses too high for effective use in our climate, year-round.

Scotland has a long heating season, right into June. Because purchased heat
is required for 9 to 10 months of the year, the more you can claw from solar
the better. Surprisingly, solar, passive and active, in Scotland makes more
sense than anywhere else in the UK. Probably the same for NI too.