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<div class="moz-cite-prefix">Dear Francesco,<br>
<br>
Thank you for sharing the link with all of us.<br>
I feel we must create more bridges between the researchers who
have worked and work on the protocols, and the people discussing
on this List. The recent article from Anna University in Chennai
is an illustration of that.<br>
<br>
I feel your paper is a major contribution to the current debate,
and a major step. You've expressed the issues in a very clear and
documented way.<br>
<br>
About the WBT, a few quotes:<br>
<br>
p 64<br>
<br>
"Therefore, the dominant practice of solely relying on WBT results
may negatively affect both stove dissemination programs and
climate impact estimates. As this practice has been further
encouraged by the definition of stoves performance rankings, by
the GACC and the ISO-IWA, based on the WBT, a deeper analysis of
the possible implications is critically needed."<br>
<br>
p 80-81<br>
<br>
"Still, some of WBT critical issues remain unsolved, with a number
of researchers claiming the protocol would need to be reviewed in
terms of precision and accuracy [76] [57] [77].<br>
A lot of debate has been made around metrics formulation,
primarily on thermal efficiency, which is often interpreted as the
most immediate and distinctive stove performance parameter."<br>
<br>
"The scientific meaningfulness of η at Low-Power has been also
questioned by Zhang et al. [57], claiming that simmering and low
power operation are not synonyms and that a proper way to evaluate
Low-Power efficiency would be simply operating the stove at the
lower power possible to heat water."<br>
<br>
"Criticism about WBT also concerns thermodynamic subjects. The
WBT is a controlled laboratory test, thus supposed to have little
uncertainty and to be effective in comparing different stove
designs. Nevertheless, the choice to approximate a typical cooking
task (boiling and simmering) is not functional to this purpose; in
fact, as documented by L’Orange et al. [78], uncertainties related
to temperature reading and vaporisation in the boiling region lead
to high variability between test replicates."<br>
<br>
"Of course, a stove which is specifically designed and optimised
for insulated pots would be performing differently without
insulation; yet testing all stoves without a lid is not a solution
either. To better understand this concept, a simple experiment on
a common European electric heater – which was actually experienced
by the author on a Severin KP 1092 (1500 Wnom) – may be performed:
the appliance, operated at its maximum power, might not be able to
heat a small pot of water (2 litres) up to the boiling point, when
no lid is placed on it; yet it may be perfectly able to perform
the task when the pot is insulated (as commonly done by the
average European user). Therefore, the electric heater would fail
to perform a WBT (even on a small pot) yet it would be perfectly
functioning from a user’s point of view. The example highlights
how stove performances are not inherent to the design, but rather
depend on several external factors (viz. pot dimensions and
insulation, as well as fuel type, moisture content and burn cycle
in case of wood burning stoves). Trying to approximate a fixed
“task” cannot be representative of the variety of cooking tasks
and habits that may be experienced in a real context of use [68]."<br>
<br>
To conclude, the WBT strengths:<br>
<ul>
<li>Highly detailed and user-friendly document, including Excel
Spreadsheet</li>
<li>Adaptability to any fuel and stove type</li>
</ul>
and weaknesses:<br>
<ul>
<li>Confusion on the protocol purpose and usefulness</li>
<li>Not suitable to assess average field performances</li>
<li>Questions on some metrics meaningfulness</li>
<li>Questions on thermodynamic issues</li>
<li>High variability between test replicates and uncertainty</li>
<li>Misleading statistical considerations</li>
<li>High number of replicates needed to obtain statistically
significant data.</li>
</ul>
<br>
Now, the study points out that no protocol is perfect, and all
protocols should be improved.<br>
<br>
And, about using the WBT and other protocols to design a stove:<br>
"Furthermore, the review analysis seems to suggest that current
testing protocols may also provide misleading guidance about stove
designs;"<br>
<br>
There's a lot of work ahead.<br>
<br>
Best,<br>
<br>
Xavier<br>
<br>
<br>
<br>
<br>
On 2/20/17 11:09, Francesco Lombardi wrote:<br>
</div>
<p>Dear all,<br>
<br>
I am pleased to inform you that we just published a new article
that you may find extremely relevant to this discussion. The title
is: "<span>Laboratory protocols for testing of Improved Cooking
Stoves (ICSs): A review of state-of-the-art and further
developments". This is the link for the downlkoad: <a
moz-do-not-send="true"
href="http://www.sciencedirect.com/science/article/pii/S096195341730065X"
class="OWAAutoLink" id="LPlnk675897" previewremoved="true">http://www.sciencedirect.com/science/article/pii/S096195341730065X</a><br>
<br>
The paper, published in Biomass and Bioenergy, performs an an</span><span
style="font-size: 12pt;">alysis of strengths and weaknesses for
each protocol based on defined indicators. </span><span></span><span
style="font-size: 12pt;">Real-life relevance, repeatability and
data evaluation are set as indicators for comparison. Based on
the analysis, a</span><span style="font-size: 12pt;">ternative
solutions for design rating and statistical analysis are
proposed and moreover we provide an out</span><span
style="font-size: 12pt;">look for the definition of a novel
standard.<br>
<br>
It is very important that the criticalities here identified are
properly discussed and solved before the publication of any
novel protocol/standard. Accordingly, we hope that you can
contribute to share the results of this study as much as
possible within the stove community.<br>
<br>
Thanks,<br>
<br>
Francesco Lombardi<br>
</span></p>
<p><br>
</p>
<i><span style="font-size:10pt"><font face="Calibri,sans-serif"
size="2"><span style="font-size:11pt">Francesco Lombardi, Eng.<br>
Researcher at Department of Energy<br>
UNESCO Chair in Energy for Sustainable Development <br>
<a class="moz-txt-link-abbreviated"
href="http://www.unescochair-e4sd.polimi.it">www.unescochair-e4sd.polimi.it</a><br>
Politecnico di Milano, via Lambruschini, 4 – 20156 – Milano<br>
Mobile: +39 338 2749066<br>
zOffice: +39 02 2399 3866</span></font></span></i>
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