[Stoves] Stoves Digest, Vol 131, Issue 9

[Norbert Senf]

Gordon West wrote:

>
> (snip)
> My guess is that for simple stove technology the test is: "if it looks
> good, it?s probably pretty good."
>

That has been our experience in PM testing using the Condar portable
dilution tunnel.
Here's a sequence of photos of the chimney exit on a downdraft heating
stove at the 2018 Stove Design Challenge in Washington DC:
http://heatkit.com/research/2018/Stove%20Design%20Challenge/Data/Stove%20Wittus/Photos/chimney%20startup%20sequence%20b.JPG

It shows the startup sequence from a cold start for a batch burn.
At the startup at 11:20 you can see a smoke plume. At 11:23 it disappears,
which means very low PM (assuming there is significant stack flow).
Shortly thereafter, you see a steam plume. It is distinguished from the
earlier smoke plume, because it is white, short and the steam disappears
again rapidly.
The steam plume indicates either cold outside temperature, or in this case,
very low stack temperature.
I have recently seen a field study from Switzerland, where one of the tools
they used was a matched set of photos of the firebox and the chimney exit,
timed
at regular intervals throughout the burn.

After many years of doing PM testing, we've learned that watching the stack
exit is one of the most useful things for figuring out what is going on in
real time with the burn.
The stove in this case had very low PM, at 0.7 g/kg

Some more photos:
http://heatkit.com/research/2018/Stove%20Design%20Challenge/2018%20Stove%20Design%20Challenge.htm

Cheers ............ Norbert

-- 
Norbert Senf
Masonry Stove Builders
25 ch. Brouse, RR 5
Shawville Québec J0X 2Y0
819.647.5092
www.heatkit.com
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