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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Dear Crispin and other friends<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>The simple explanation given in your 4-pager example of feeding charcoal produced in one stove into a second charcoal burner is really useful. My only quibble is with the nomenclature of efficiency.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>The nomenclature that we seem to have been driven towards in the ISO process is:<o:p></o:p></span></p><p class=MsoNormal><b><span style='letter-spacing:-.05pt'>Fuel Efficiency</span></b><span style='letter-spacing:-.05pt'>: </span>The ratio of the <b>Energy Used</b> to the <b>Energy Released<o:p></o:p></b></p><p class=MsoNormal style='text-indent:36.0pt'><span style='color:#1F497D'>Where<o:p></o:p></span></p><p class=MsoNormal style='margin-left:36.0pt'><b>Energy Used</b>: The product of the <b>Heating Value</b> of the <b>Fuel Consumed</b> and its mass, less the product of the <b>Heating Value</b> of the <b>Unusable Fuel</b> and its mass.<o:p></o:p></p><p class=MsoNormal style='text-indent:36.0pt'><span style='color:#1F497D'>And<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'> </span><b><span style='letter-spacing:.05pt'>Energy Released: </span></b><span style='letter-spacing:.05pt'>The energy that would be released by the complete combustion of the <b>Fuel Fed.<o:p></o:p></b></span></p><p class=MsoNormal style='margin-left:72.0pt'><b><span style='letter-spacing:-.05pt'>Fuel Fed: </span></b><span style='letter-spacing:-.05pt'>The unburned fuel supplied to a <b>Cookstove</b> during the course of the <b>Burn Sequence, </b><i>which may include fuel recycled from an earlie<b>r Burn Sequence</b></i><b> </b></span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>The <i>italicized</i> part of the last definition is not yet formally part of the story, and the definition of Energy Used may need a bit more tweaking.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b>Thermal Efficiency</b>: The ratio of <b>Useful Energy Delivered</b> to <b>Energy Used<o:p></o:p></b></p><p class=MsoNormal style='text-indent:36.0pt'><span style='color:#1F497D'>Where<o:p></o:p></span></p><p class=MsoNormal style='margin-left:36.0pt'><b>Useful Energy Delivered</b>: The energy transferred to the contents of a <b>Cooking Vessel</b>, including sensible heat that raises the temperature of the vessel and the latent heat of evaporation of water from the vessel.<o:p></o:p></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Your definitions are exactly reversed! Yet the literature treating the thermal efficiency as the ratio of the energy delivered to the pot to the energy used is quite widespread and we have had numerous comments to that effect, so I am inclined to think it is the preferred term. In the interests of clarity, can we agree which is which?<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Best regards<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Prof Philip Lloyd</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Energy Institute</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Cape Peninsula University of Technology</span><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>PO Box 1906<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Bellville 7535<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Tel: 021 959 4323<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Fax: 086 778 0257<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Cell: 083 441 5247<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>PA: Nadia 021 959 4330<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='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 style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Stoves [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Crispin Pemberton-Pigott<br><b>Sent:</b> 28 November 2015 12:38<br><b>To:</b> Stoves<br><b>Subject:</b> [Stoves] Analysis of a two-stove cooking system<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-CA>Dear Friends<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>As a contribution to the discussion on the ways one might rate the performance of a two-stove cooking system in which one stove makes charcoal and another burns it, I have drafted the attached paper for discussion.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>I would be pleased to edit or extend it to account for ideas you may have about this topic. Because charcoal making stoves could be used to generate fuel use in the same home or for sale, the question as to how such a system can be rated will inevitably arise.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>Please feel free to distribute it as you deem appropriate.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA>Regards<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA>Crispin<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-CA><o:p> </o:p></span></p><p class=MsoNormal style='background:white'><span lang=EN-CA style='font-size:8.0pt;font-family:"Garamond","serif";color:black'>Crispin Pemberton-Pigott</span><span lang=EN-CA style='font-family:"helvetica neue";color:black'><o:p></o:p></span></p><p class=MsoNormal style='background:white'><span style='font-size:8.0pt;font-family:"Garamond","serif";color:black'><a href="mailto:crispin@newdawn.sz"><span style='color:blue'>crispin@newdawn.sz</span></a></span><span lang=EN-CA style='font-size:8.0pt;font-family:"Garamond","serif";color:black'><o:p></o:p></span></p><p class=MsoNormal style='background:white'><span lang=EN-CA style='font-size:8.0pt;font-family:"Garamond","serif";color:black'>Managing Director</span><span lang=EN-CA style='font-family:"helvetica neue";color:black'><o:p></o:p></span></p><p class=MsoNormal style='background:white'><span lang=EN-CA style='font-size:8.0pt;font-family:"Garamond","serif";color:black'>New Dawn Engineering</span><span lang=EN-CA style='font-family:"helvetica neue";color:black'><o:p></o:p></span></p><p class=MsoNormal style='background:white'><span lang=EN-CA style='font-family:"helvetica neue";color:black'><a href="http://www.newdawnengineering.com/" target="_blank"><span style='font-size:8.0pt;font-family:"Garamond","serif";color:blue'>www.newdawnengineering.com</span></a><o:p></o:p></span></p><p class=MsoNormal style='background:white'><span lang=EN-CA style='font-size:8.0pt;font-family:"Garamond","serif";color:black'>Matsapha, Swaziland / Waterloo, Canada</span><span lang=EN-CA style='font-family:"helvetica neue";color:black'><o:p></o:p></span></p><p class=MsoNormal style='background:white'><span lang=EN-CA style='font-size:8.0pt;font-family:"Garamond","serif";color:black'> </span><span lang=EN-CA style='font-family:"helvetica neue";color:black'><o:p></o:p></span></p></div><div style="position:absolute;margin:15px 0 0 0px; padding-top:10px;padding-right:15px;min-width:350px; border-top:1px solid #ccc;font-size:12px; color: #333; font-family:arial,'Hiragino Sans GB',Tahoma,Helvetica,STHeiti; ">This email has been protected by YAC (Yet Another Cleaner) <a href="http://www.yac.mx?source=email" style="display:block;padding-top:5px; color:#2bafed;text-decoration:none;">www.yac.mx</a></div></body></html>