[Stoves] Improving Thermal Efficiency (TARP-VE)

[Crispin Pemberton-Pigott]

Dear Alex

You have raised an important question that relates to Dean's plan to use a
hood-based measurement system to tune the stove's performance.

"However TLUDs are being promoted for use with a variety of fuels for which
tuning may imply a fairly wide band, with more excess air."

Dean is promoting the use of a hood-based measurement system that does not
measure excess air. IF you do not know what the EA is, the only thing you
can do is conduct an entire test and compare the result with some earlier
test hoping to spot a difference.

The problem with this approach is that it is really hard to know when the EA
was right and when it was not, and what the PM was a the time. The CO/CO2
ratio is a sensible measure of combustion efficiency. Again, if you do not
measure it where are going to get the knowledge from about what is happening
in the fire?

It is no accident that combustion analysers were invented. They are used for
tuning stoves and I encourage anyone who wants to develop stove products to
buy one and learn how to use it and the numbers it produces.

Investing in a scale that will hold the stove provides a great deal of
additional information such as the real time power level and the total
emissions of any gas product during various EA conditions, without having to
have a hood system at all. Cheaper too.

Alex I really must pop over to have a look at the pellet burner. Prof
Annegarn will be coming to visit as well. You are onto something with really
good potential that is not a TLUD with all its attendant problems. I have
some switchgrass pellets from Roger Samson of different sizes.

Roger, are you following this? Do you want to drive to Kingston for a day or
so? Alex is up to his old tricks of leading the field...

Thanks.
Crispin