[Stoves] FW: REQUEST for complete sets of raw data of cookstove tests.

Mon Apr 22 09:47:51 CDT 2013

Dear Jim and Anyone watching

I won't have time to dig through the messages on this thread that were in
limbo. If something is really important to someone, ask again.

With regard to the char remaining and the wood that has been burned on one
end (fuel left over from tests) Harold Annegarn and I have a proposal for
how to deal with stoves that can use fuel remaining from a previous burn. In
principle, the test should be started with the fuel left over from a
previous test. In other words a cooking task that is replicated a number of
times in which the fuel left over goes into the stove for the subsequent
task provides an opportunity to measure (quite accurately) the raw fuel
drawn from the pile.

Any charcoal that is not being discarded and all partially burned, dried,
blackened stoves that are claimed to be useable fuel, not discarded, should
be used. If new fuel is needed (which it will be) then that new fuel is raw
fuel.  It becomes quite a simple matter to measure how much new fuel is
required for each identical replication of a task.

The issue is discussed in the attached document in '1. Replications'.

A number of definitions are provided in the subsequent sections that are
useful for discussing tests and efficiencies.

Importantly, if a stove cannot use any of the fuel remaining (an example
might be a TLUD wood burner that makes a high % of char) the energy in the
remaining fuel cannot legitimately be counted as cooking fuel - because it
can't be used in that stove for cooking.

It then becomes and easy matter to determine the raw fuel consumption per
cycle for that task.

Regards

Crispin

-----Original Message-----

To All,

Resending my comment below, even though we've moved on in the conversation,
because I've just learned my comment didn't post to the listserv the first
time, and I wanted to make sure people know EPA is currently working on a
way to share raw data - we'd be very happy to be able to share this
information with the community.

Jim

-----Original Message-----

Dear Paul,

It was good to see you again in Phnom Penh, and I wish we had had more time
to talk, but I hope you'll accept my invitation to visit us soon in North
Carolina.  I understand you believe stove testing is an extremely important
issue, and we completely agree on that point!

You requested raw data to help with ".finding out if results from
sub-optimal earlier versions of WBT can be re-processed (processed forward)
to be compatible with version 4.2.1."  Our (EPA) testing in 2010 was based
on Version 4.1.2.  Changes made in the WBT data calculation spreadsheet
between Versions 4.1.2 and 4.2.1 are documented at the web site:

 <http://community.cleancookstoves.org/files/354>
http://community.cleancookstoves.org/files/354

The documented changes made in the WBT calculation sheet between Versions
4.1.2 and 4.2.1 do not make any difference in results from our testing in
2010.  We can discuss each change that was made in the calculation sheet,
and I can explain why it doesn't affect our previous results.  Changes made
between versions might affect results from some other stove-testing labs.

As Crispin has pointed out, one thing that would make a big difference in
results is how "remaining char" is handled in the calculations, but this has
not been changed in the WBT protocol or spreadsheet.  Crispin and I have
previously discussed this offline as well as on the stoves listserv, and I
think Crispin and I agree that if remaining char is discarded in practice,
then the calculations in the WBT should reflect that practice.  This is an
issue for the next revision of the WBT, and it would especially affect
results for charcoal-producing stoves (such as charcoal-producing TLUDs).
Meanwhile, we (EPA) will report future results per the current WBT protocol
(energy in remaining char gets full credit in energy calculations), and we
will also report results for the discarded-char scenario (energy in
remaining char gets no credit).

Results from our 2010 testing showed that a charcoal-producing TLUD stove
burning wood-pellet fuel had very high thermal efficiency compared to all
other stoves tested.  But if the remaining char is discarded, the efficiency
for the TLUD would be significantly lower.  We haven't seen a need to report
efficiency with discarded char for that TLUD prototype we tested, because
that stove has not been manufactured or disseminated, but for the two
TLUD-type stoves included in the ongoing round of testing, we will report
results both ways - char discarded and not discarded.

Back in October 2011, Crispin and I spent some good time comparing results
from Crispin's proposed (for Version 4) WBT spreadsheet and our (EPA)
spreadsheet - I still have the record of our email correspondence.  We
generally found agreement between results, and we were able to explain some
minor differences in results.  Rather than rehash old data now, I think it's
much more productive to continue to work cooperatively together to do the
challenging work ahead of us to: (1) refine existing protocols, (2) develop
new protocols, as needed, and (3) build up the network of Regional Testing
and Knowledge Centers.

I think the Alliance (Ranyee) is doing a fine job facilitating an inclusive
open process for moving forward - great discussions and progress in Phnom
Penh!

We (at EPA) are working hard on a process (meeting EPA QA and review
requirements) that will enable us to effectively share the raw data along
with results from our ongoing round of stove testing.  Hope this will be
helpful.

Please call me if you would like to discuss this further.

Sincerely,

Jim

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