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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-ZA link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Dear Kirk<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I have lurked during this discussion – forgive me for entering it now.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>You believed “the increase in ambient room temperature had changed the turn-down performance of the stove.” <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>You may have been mistaken. I think what happened was that the ambient room temperature changed the measurement you were attempting to make. At the higher ambient temperature there was less rate of heat loss from the cooking pot, so it took less fuel to keep it hot and the turndown ratio – as you define it – changed. So the problem may lie with your definition of the turndown ratio. I use the minimal sustainable firepower, determined from the rate of fuel feed which just keeps the fire going, as my lower measure, and the maximum firepower I can achieve without significant oxygen starvation as the upper one, and have yet to see the sort of effect of ambient temperature on the ratio of the upper to the lower that you report with your definition of the ratio.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>In a word, you may be picking up a change in the heat transfer from the pot as the ambient temperature changes, rather than anything fundamental about the stove performance.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I hope that suggestion assists.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kind regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Prof Philip Lloyd<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Energy Institute, CPUT<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>SARETEC, Sachs Circle<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Bellville<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Tel 021 959 4323<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Cell 083 441 5247<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>PA Nadia 021 959 4330<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Stoves [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>kgharris<br><b>Sent:</b> Tuesday, May 31, 2016 8:08 AM<br><b>To:</b> Discussion of biomass cooking stoves<br><b>Subject:</b> Re: [Stoves] stove test<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Crispin,</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>My original statement was to point out how the increase in ambient room temperature had changed the turn-down performance of the stove. This is an important topic if the stove principles are going to have any effect in hot tropical countries. If you can comment on this I would be happy to learn from your experience, but please stop hijacking my posts and misdirecting attention to cater to your agenda against the current test methods. Start your own thread if that is what you want to talk about.</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>All,</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>I will be happy to answer questions about the burning abilities and tecniques of our stove and combustor.</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Kirk</span><span lang=EN-CA><o:p></o:p></span></p></div><blockquote style='border:none;border-left:solid black 1.5pt;padding:0cm 0cm 0cm 4.0pt;margin-left:3.75pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>----- Original Message ----- <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:#E4E4E4'><b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>From:</span></b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <a href="mailto:crispinpigott@outlook.com" title="crispinpigott@outlook.com">Crispin Pemberton-Pigott</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>To:</span></b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <a href="mailto:stoves@lists.bioenergylists.org" title="stoves@lists.bioenergylists.org">'Discussion of biomass cooking stoves'</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Sent:</span></b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'> Monday, May 30, 2016 9:40 PM<o:p></o:p></span></p></div><div><p class=MsoNormal><b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Subject:</span></b><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'> Re: [Stoves] stove test<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p></div><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Dear Kirk<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>></span><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'> With the support of Aprovecho Research Center, I (actually we) have developed a very good, clean burning TLUD-ND. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I think you have done exactly that. Good on you.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>There is no misdirection at all here. You are past the verge of changing the stove’s superior performance in order to get a better rating on an invalid metric. It is that simple. Don’t get sucked into that trap. When you are getting results as good as you are, there are new opportunities to go wrong. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The only ‘misdirection’ has been supplied for years by test methods that guided people to edit their stoves to meet spurious requirements that did not bear directly on performance, or worse, actually penalised stoves for their superior performance. A good example is attached.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>This is not something new in the stove community. Here is a quote from the attached Aprovecho document from 2003:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><i><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>“Why was the good advice, by established experts in the field, represented in the VITA International Standard test, the result of several well funded international conferences, obscure in 2003? Both the Indian and Chinese governments developed tests of their own widening the scope of PHU to include power, rate of evaporation, time. Visser (2003) published a version of a water boiling test based on efficiency and appropriate power for boiling and simmering. What motivated this parallel activity? Why isn’t the VITA test in more general use?”<o:p></o:p></span></i></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>One reason the VITA test was not more popular was it had several conceptual errors and a few really poor metrics that gave mis-directing outputs. One is the efficiency of simmering, another is the concept of specific fuel consumption for simmering. Another was the idea of an ‘average efficiency’ meaning an ‘average thermal efficiency’. I believe from my research that the specific fuel consumption for simmering and the average efficiency were both introduced by Baldwin in 1986 or so, before his book came out. Neither are acceptable metrics.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The document refers to the VITA test the ‘international standard’ which is not supported by the evidence. Three or four minor parties agreed to it and it was never used by the major markets in India and China. Even Eindhoven University didn’t use it and they were a party to drafting it. India pretty much adopted the minority position taken by KK Prasad from Eindhoven and built that into their 1991 test. The Chinese test from that era was very similar. India, interestingly, produced a list of 28 standard sizes of cooking pot which is a record, I believe!<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The long-forgotten organisation Bois de Feu had a clear understanding of these issues and had a test method in 1982 that didn’t have these problems. They treated the simmering phase very carefully (and differently). Prasad (and Visser who was his student) developed multiple test methods over the years. Piet Visser and I created one in Malawi in about 2007 which later evolved into the ProBEC Test for heat transfer efficiency which is now a SeTAR SOP, currently v1.05 (SeTAR is an independently managed continuation of the 13 year long GIZ/ProBEC project). It doesn’t really predict performance, it gives a real-time heat transfer efficiency report under varying conditions. It is very easy to perform and it supports pot-swapping, similar to the Indian protocol.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>So, ladies and gentlemen, there are no Tier 4 stoves. That achievement will have to wait for the development of appropriate, valid low power metrics and one will need an equipment set capable of quantifying the result.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kirk: don’t be bamboozled. You are doing good work. Nothing is perfectly correct. Independent investigation of truth is still required.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Best wishes<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>All,</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>With the support of Aprovecho Research Center, I (actually we) have developed a very good, clean burning TLUD-ND. This is real and proven and no amount of misdirection can change that. It will be at Aprovecho for stove camp for all to examine, and I will be giving a presentation on how it burns so clean.</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Respectfully,</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Kirk</span><span lang=EN-CA><o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA> <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-CA style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Santa Rosa, CA. USA</span><span lang=EN-CA><o:p></o:p></span></p></div><div class=MsoNormal align=center style='text-align:center'><span lang=EN-CA><hr size=2 width="100%" align=center></span></div><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-CA>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br><a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a><br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br><a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a><br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br><a href="http://stoves.bioenergylists.org/">http://stoves.bioenergylists.org/</a><o:p></o:p></span></p><div class=MsoNormal align=center style='text-align:center'><span lang=EN-CA><hr size=2 width="100%" align=center></span></div><p><span lang=EN-CA>No virus found in this message.<br>Checked by AVG - <a href="http://www.avg.com">www.avg.com</a><br>Version: 2016.0.7598 / Virus Database: 4591/12332 - Release Date: 05/31/16<o:p></o:p></span></p></blockquote></div></body></html>