<html><head></head><body style="background-color: rgb(255, 255, 255); line-height: initial;"> <div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br>Dear Frank</div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">Always happy to see people are thinking about testing. Some critical issues that must be addressed when testing:</div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">Suppose the energy consumption, which you mention towards the end, is not the major concern of the user, but PM emissions is the biggie?</div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">Suppose the program funder wants to know how long the pile of fuel will last, rather than how much energy is extracted from the pile? These numbers are quite different, particularly when comparing stoves that don't burn the fuel completely. </div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);"><br></div><div style="width: 100%; font-size: initial; font-family: Calibri, 'Slate Pro', sans-serif; color: rgb(31, 73, 125); text-align: initial; background-color: rgb(255, 255, 255);">Suppose when using a new stove the household changes their behaviour a lot and uses it more to keep food warm and provide more light? If they have more burning hours available from the same pile of fuel, they may want to use them, not save fuel as it is already there. In short, do you want to measure the performance of the family or the performance of the stove?</div><div id="_originalContent" style=""><div><p>These very practical questions affect the design of the test. Another aspect is fuel preparation. Should time needed to cut squares fuel be considered? What about fuel flexibility? That is a major issue with users. What about moisture flexibility? Ditto. </p><p><span style="line-height: initial;">If we don't ask enough questions, we can't identify a good fit between a particular group of users and the available stock of stoves. In the case of a DGIS-funded project at ProBEC, they accepted the less-than-optimal fuel reduction because the lifestyle of the people was improved by running the stove longer each day which they described as 'access to modern energy' which was the main programme goal. </span></p><p><span style="line-height: initial;">Pretty cool I think!</span></p><p><span style="line-height: initial;">Regards </span></p><p><span style="line-height: initial;">Crispin </span></p><p><span style="line-height: initial;"><br></span></p><p class="MsoNormal">Greetings Stovers,</p><p class="MsoNormal">My suggestions:</p><p class="MsoNormal"><br></p><p class="MsoNormal">Test methods for comparing Stoves.<o:p></o:p></p><p class="MsoNormal"> <o:p></o:p></p><p class="MsoListParagraphCxSpFirst" style="text-indent:-.25in;mso-list:l0 level1 lfo1">1)<span style="font-size: 7pt; font-family: 'Times New Roman';">
</span><!--[endif]-->The units of interest: There are two we are
interested in when picking out a stove. (a) biomass / task and (b) time / task<o:p></o:p></p><p class="MsoListParagraphCxSpMiddle" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><!--[if !supportLists]-->2)<span style="font-size: 7pt; font-family: 'Times New Roman';">
</span><!--[endif]-->Variable = the Stove. We swap out different
stoves, run the test and compare the results for biomass per task and time per
task.<o:p></o:p></p><p class="MsoListParagraphCxSpLast" style="text-indent:-.25in;mso-list:l0 level1 lfo1"><!--[if !supportLists]-->3)<span style="font-size: 7pt; font-family: 'Times New Roman';">
</span><!--[endif]-->Controls; there are two: (a) fuel at one end and
(b) task at the other.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Control (a) Fuel<o:p></o:p></p><p class="MsoNormal">We walk up to the stockpile of fuel in town that has been
gathered and piled and pull out what we want.
If we want to test a Rocket Stove using 2.5cm X 2.5cm X 10 cm long kiln
dried sticks we pull out the bigger pieces and have them sawed and dried. The rest of the pile we carry back to the
forest and scatter around under the trees.
Paul for his TLUD needs uniform pieces to keep an even flame front so he
takes out what he wants, chips them to size, and screens out the fines. The fines and overs are carried back to the
forest and scattered. Richard collects
the material he can turn to mush and sends the rest back. Stoves using pellets and sticks are done the
same. Use whatever you want as long as
it comes from the pile.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Control (b) Task<o:p></o:p></p><p class="MsoNormal">The task chosen must have a clear end point. The start is easy – it’s when the match is
struck. <o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Everything else is NOT part of the test. Our goal is to reduce by elimination
variables and get control over the ones left so the test can be conducted at
any lab and all will come out with the same results. <o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">We don’t care about the chemistry of the gases, smoke, 2.5
pm, stability of the stove, toxic chemicals, hot surfaces that can burn, or
anything else. If Stove A works better
than Stove B then check the gases, make some adjustments and have Stove B
re-tested. If, for example, Stove A completes a task using less biomass and in
a shorter time than Stove B but stove A produces a lot of smoke – then Stove A
wins.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Everything else are ‘Conditions’ that must be meet. There are lots of them: paint streaked with
runs on new stoves produced is a condition unacceptable, poor welds, toxic
galvanized metals, poor quality metal – all conditions unacceptable. Smoke, toxic gases, hot surfaces or unstable
are all conditions unacceptable. Too
heavy to move or won’t take my favorite pot are more conditions. But these have nothing to do with the Test. <i>We need to keep the Test real simple</i>. All the Conditions in the list must pass or
don’t bother doing The Test OR make corrections before testing. <o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Also;<o:p></o:p></p><p class="MsoNormal">Control (a) Fuel; we are interested in mass of the biomass
used but we can normalize it to energy for convenience and when comparing ‘like
fuels’ when the on-site fuels are not available. When measuring energy I fully agree with the
method Dean used at Stove Camp. The problem is there are so many unknowns and
guesses of the energy content of the different parts of the fuel. Perhaps its possible to get good precision
(replicates) but I can’t see how the accuracy (real value) could even be close.
Therefore, without knowing of a better replacement, I believe the E450v energy
value for the fuel is the best one to use because it is easier to determine. I realize E450v has its own limitations.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Regards<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Frank<o:p></o:p></p><p class="MsoNormal">(retired) </p>
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Frank Shields<br><a href="mailto:franke@cruzio.com">franke@cruzio.com</a><br><br>
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