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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Dear Paul<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Several agreeable things in that message:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>></span>It is time to get serious about how TLUD stoves have superior performance. <span style='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'>Well, let’s be cautious here, though I agree they are better than a lot of things that came before. It just raises the bar. We can build very clean stoves they are not TLUDs y’know.<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='color:#1F497D'>></span>We can wait for Dean and Jim and ALL OTHER STOVE TESTING CENTERS to provide some data. <span style='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'>I look forward to people providing the spreadsheets, filled in, so those of us who, like Jim, are adding metrics can do so based on the raw rata we need.<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><br>1. "Fan stoves" is a BAD name. Any stove with a fan can be a "fan stove". <span style='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'>Exactly. No ‘type’ of stove is automatically ‘good’. There are some terrible TLUD’s that I have tested (manufactured ones, not one-offs) and that convinced me there are many things to get wrong with a TLUD. <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='color:#1F497D'>></span>What Jim and Dean are discussing are stoves that include Oorja, Biolite (two models?), Philips, Reed Woodgas Campstove, maybe some units from China. At least THREE different combustion regimes are included in the above named stoves. <span style='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'>There are dozens of different fan-assisted stoves in China. Some are TLUD’s and some are not.<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>2. "Stoves with fans" is also not sufficiently specific, but at least they could be recognized for what they are, which is, stoves of different types that have fans. <br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Agreed.<o:p></o:p></span></p><p class=MsoNormal><br><span style='color:#1F497D'>>…</span>jets of air consume small quantities of pellet fuels in a small cup-type combustion chamber. For sure these are NOT TLUD stoves. <span style='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'>Agreed. Having a fan is not a guarantee of anything other than it has a fan.<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>C. They could be "Simple Improved Cookstoves - ICS - with fans". Something like a bucket-stove with a fan blowing onto the flaming fuel. No examples come to mind, but add a fan and have a "fan stove." <br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Agreed. Good point.<o:p></o:p></span></p><p class=MsoNormal><br>D. They could be "TLUD stoves with fans". Yes, TLUD stoves can be operated with fans. The opening statement is referring to natural draft TLUD-ND having less PM than TLUD-FA. <span style='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'>That is not a helpful comment. Any stove <i>type</i> can be made better that it was in the past. It is pointless to claim that a type of stove is cleaner yatta-yatta. There are bad and good versions of every type of 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>3. So, one study that needs to be done is to compare the PM from TLUD-ND and TLUD-FA. Do such results already exist? <span style='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'>I want to be clear that even if it did exist, it is an assessment of those models at that time. No sweeping generalisations please. It is also dependent on the protocol used. As Jim pointed out several times today in the webinar, if the calculation of efficiency is made incorrectly, the stove is incorrectly rated for efficiency. As the same calculation that provides the energy number for the efficiency is converted to ‘dry fuel equivalent’ (meaning equivalent to that amount of energy) and that is in turn ‘understood’ to be the fuel consumption, there are serious implications if the protocol used does not correctly assess what to do with the charcoal. ‘Misleading claims’ is perhaps a better expression.<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>4. BUT. Yes, there is a BIG BUT to be considered. This is because TLUD-FA (those with fans) have been blatantly mis-used and the test results could be erroneous because the test was not stopped when the TLUD pyrolysis process stopped, which is when the bottom burning of char started and continued as long as operators were feeding in raw fuel at the top. <span style='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'>There are all sorts of issues affecting the test results for these stoves. It is a major point of discussion as to whether the test is supposed to assess the fuel consumption in real life (meaning as used) or assess the heat transfer efficiency because some designer wants to know what it is. The protocols and calculations are quite different. If the stove cannot normally be extinguished, then why would the fuel remaining at the end of cooking be credited as ‘not having been burned’ when there is no way to turn it off and even it if did, the fuel cannot be used in the next fire (in some cases). The fuel consumed from the supply each time the task is replicated is the fuel consumption. No getting around it by fancy mathematics. We have to keep our eye on that figure because in almost all cases stove programme are intending to reduce that consumption per household per day.<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>I repeat: the TLUD testing needs to be <i><u>stopped when the TLUD pyrolysis process stopped, which is when the bottom burning of char started and continued as long as operators were feeding in raw fuel at the top. </u></i><br><br><span style='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 think you are going to have to sell the idea that a) it can be stopped and b) that if it does, less fuel will be used.<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'>Are you thinking of fuel consumption or CO and PM as the issue? What is prevented/avoided if the test is stopped at some well-described time?<o:p></o:p></span></p><p class=MsoNormal><br>In conclusion, let's get our understanding clear that the addition of a fan to a stove does NOT automatically put that stove into the Tier 3 and Tier 4 categories of low PM emissions. FIRST think of what kind of combustion the stove utilizes: simple ICS, Rocket, TLUD, other micro-gasification, other .... THEN consider if it has a fan in it. <br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Agreed.<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>STATEMENT: I believe that the TLUD stoves (whether ND or FA) are cleaner about PM than the other combustion regimes because the process of pyrolysis leaves the inert materials (non-combustibles known as ash) held tightly to the charcoal that is created. So, do NOT burn the charcoal. Especially do not burn it with vigorous streams of air at the level of the charcoal. [And there are probably additional variables to be studied.]<br><br>This hypothesis remains to be proven. <span style='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'>I don’t think this will stand up to scrutiny because there are lots of ways to burn fuel. The point about the ash being lofted is a major one. If fans blow the ash into the air and it gets away, there is OM but is it dangerous PM? Is a condensed volatile compound a lot more dangerous? Perhaps the BC vs OC split is more important than the mass of PM2.5.<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'>Quick note to Dean in reply about the mass of PM – the mass of the nanoparticles is so small that it is difficult to estimate what the influence is, if there is a large filter picking up everything up to PM10. My point is that there seems to be a bit of chatter about counting the number of particles when they are small, but determining the mass. This it is not much help to collect the UFP on the same filter as there is hardly anything there. I hoped it would be easier but it is not.<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>But while we wait for the test results, money will be channeled to other stove technologies, field tests of health will be conducted withOUT having a TLUD stove included in the study, and people will continue to suffer (and some will die) because of the high PM levels in household cookstoves. It is late 2013 and studies of TLUD stoves are only scratching the surface of what things need to be studied.<span style='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'>I hear you. I do not hear you exclusively, however. There are other ways to burn very cleanly with extremely low PM. If you want to get a hearing you will have to (as far as I see it) include any stove that burns really well, not just TLUDs, however much they are loved in some circles. Everything that is clean and good about a TLUD applies to crossdraft stoves, plus they can be refuelled and if you like, char can be harvested periodically.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><br>You are asking for the ear of generalists (testers) while proposing specialist interests. Assessing a stove is going to cost about a grand. Bring money, I guess.<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'>Tell you want, how about providing a list of exactly the tests you think should be performed that would give the most bang for the buck. What do you feel needs to be shown? <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 believe it is the heat flux rate, the CO and PM per net MJ in the pot, and the system efficiency, plus char mass remaining (but not analysed). Those can all be assessed at the same time. That would give you fuel consumption, specific emissions per MJ, and a power rating. If you have that for a dozen stoves would you be happy?<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 would propose that all the data be made available with the proviso that the producer of the data owns it for publication purposes. They should co-author anything that uses it.<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'>How does that sound?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks<br>Crispin<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></body></html>