"Andrew Gabriel" wrote in message
...
In article ,
"sro" writes:

Yes I know that efficencies have increased although I do take issue with
the
way the plumbing/heating
trade love to quote "efficiencies" of more than 100% without explaining
the
particular scam they are
using to break the laws of thermodynamics.

What would you define as 100% efficient?
Let's suppose you define it as a condensing boiler whose flue
gasses are at the same temperature as its air intake. Now I come
along and invent a scheme for recovery of the latent heat of
fusion from the condensate (i.e. this boiler spits out ice cubes
instead of a dribble of condensate). So my boiler is now 120%
efficient according to your scale, but I didn't break any of
the laws of thermodynamics.

Now just hang on whilst I nip off to the patent office...

Energy in = Energy out I suppose.
Obviously we then argue about what energy in means, but when you know that
some heat goes out the flu
etc etc
then we argue about what consitutes the system - it is not that simple, but
I do feel that the phrase
"efficiency 100%" is very misleading. A bit like lifetime guarantees on
car parts.

I know a bit about how they do their sums and it doesnt include the heat
that you get from condensing
the flue gasses. they basically dont include a large portion of the "energy
in", that way you get
better sounding figures.

Anyhow, isnt there some issue about entropy that means that you can never
get 100% conversion ?

Perhaps I ought to look it up.......

Steve