On Sat, 25 Oct 2008 16:05:41 +0100, Bill wrote:

What comes out does feel quite hot, so I'd have thought that a further
heat exchanger stage might be worthwhile. If the condensing boiler were
not condensing every bit of steam, this could also capture the residual
latent heat. Are there such things as add-on heat exchangers or would
this have to be a bodge it and see winter project?

There is one on the market: I think Alpha make it. I presume it may only
be used with their own boilers since a boiler's flue is an integral
part of the installation and using a non-approved component would
make the installation illegal. So if Alpha's unit only works with Alpha
boilers one wonders why they don't just build it into their boilers rather
than selling it as an expensive extra. I suspect the answer is in P. T.
Barnum's famous dictum :-)

As for "worthwhile", as Andrew Gabriel points out in another post it's
a question of diminishing returns: today's condensing boilers are a good
compromise between efficiency and cost and complexity.

--
John Stumbles

The astronomer married a star