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</o:shapelayout></xml><![endif]--></head><body 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 Ron<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'>The article was less technically correct that it first appears – that’s why I said not to take number too seriously.<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'>If the CO/CO<sub>2</sub> ratio is the metric used to define combustion inefficiency, then yes it is quite possible for a fire, from ignition to extinguishing, to have an average ratio of 10%. The problem is people report all sorts of mismatched metrics so one has to never accept something at face value. It was good you asked what the efficiency definition was. That is the right question. I would have given different answers to the question about average CO/CO<sub>2</sub> ratios for average (baseline) stoves.<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'>The efficiency reported in the article is completely backwards. Chris was talking about the combustion efficiency metrics which is an inefficiency and the author thought it means the cooking efficiency or something. <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'>I checked on of the HPT test results and I hope Chris is OK with me reporting it was 30% and that was the overall system efficiency. That is calculated as: the energy accumulated in the pot divided by the energy theoretically available from the mass of fuel consumed during the whole burn cycle. The heat transfer efficiency is of course higher than that.<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'>I only checked one of many tests so I won’t report anything else. I just want you to know where the fuel saving number came from, correcting the misinformation in the published article.<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'>Other biomass stoves emerging from South Africa make similar claims: Rocket Works 38% and Vesto 35% calculated on the same basis and burning the same fuel (Black Wattle).<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'>Regards<br>Crispin<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'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0mm 0mm 0mm'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> Ronal W. Larson [mailto:rongretlarson@comcast.net] <br><b>Sent:</b> Thursday, March 13, 2014 12:25 PM<br><b>To:</b> Crispin Pemberton-Pigott; Discussion of biomass<br><b>Cc:</b> Bradnum, Chris<br><b>Subject:</b> Re: [Stoves] Chris Bradnum's stove makes an appearance<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Crispin: (adding Chris (with acknowledgement of a message) and List)<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><span class=apple-tab-span> </span>Assuming that the “in” in inefficiency just got lost, is a 10% combustion inefficiency conceivable (or normal) for a rocket type of wood stove?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Ron<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Mar 13, 2014, at 6:41 AM, Crispin Pemberton-Pigott <<a href="mailto:crispinpigott@gmail.com">crispinpigott@gmail.com</a>> wrote:<o:p></o:p></p></div><p class=MsoNormal><br><br><o:p></o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'>That test was probably the heat transfer efficiency - I will have to check. The product was in the development phase but it may have been the overall system efficiency. <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'>The article called the combustion inefficiency the combustion efficiency. Don't take any of the numbers too seriously. <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Regards <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Crispin <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='font-family:"Calibri","sans-serif";color:#1F497D'>BB10 Rocks!<o:p></o:p></span></p></div><table class=MsoNormalTable border=0 cellpadding=0 width="100%" style='width:100.0%;background:white;border-spacing:0px'><tr><td style='padding:.75pt .75pt .75pt .75pt;font-size:initial;text-align:initial'><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0mm 0mm 0mm' id="_persistentHeader"><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From: </span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Ronal W. Larson<o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Sent: </span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Wednesday, March 12, 2014 23:59<o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>To: </span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Discussion of biomass; Crispin Pemberton-Pigott<o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Subject: </span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Re: [Stoves] Chris Bradnum's stove makes an appearance<o:p></o:p></span></p></div></div></td></tr></table><p class=MsoNormal style='background:white'><o:p> </o:p></p><div><div><p class=MsoNormal style='margin-bottom:12.0pt;background:white'>Crispin cc list<br><br> Can you explain the efficiency definition that is being used at UJ?<br><br>Ron<br><br><br>On Mar 12, 2014, at 9:04 PM, Crispin Pemberton-Pigott <<a href="mailto:crispinpigott@outlook.com">crispinpigott@outlook.com</a>> wrote:<br><br>> Dear Friends <br>> <br>> <a href="http://www.engineeringnews.co.za/article/uj-develops-energy-efficient-stove-for-low-income-households-2014-03-12/rep_id:3182">http://www.engineeringnews.co.za/article/uj-develops-energy-efficient-stove-for-low-income-households-2014-03-12/rep_id:3182</a><br>> <br>> This is not a technically exact report but there is not really any bad publicity for improved stoves. <br>> <br>> Well done Chris. <br>> <br>> Regards <br>> Crispin <br>> _______________________________________________<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><br>> <o:p></o:p></p></div></div></div></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></div></div></body></html>