<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;
color:black;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
color:black;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0cm;
margin-right:0cm;
margin-bottom:0cm;
margin-left:36.0pt;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;
color:black;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;
color:black;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:487865290;
mso-list-type:hybrid;
mso-list-template-ids:896178188 269025295 269025305 269025307 269025295 269025305 269025307 269025295 269025305 269025307;}
@list l0:level1
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;}
@list l0:level2
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;}
@list l0:level3
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level4
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;}
@list l0:level5
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;}
@list l0:level6
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
@list l0:level7
{mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;}
@list l0:level8
{mso-level-number-format:alpha-lower;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-18.0pt;}
@list l0:level9
{mso-level-number-format:roman-lower;
mso-level-tab-stop:none;
mso-level-number-position:right;
text-indent:-9.0pt;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</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='color:#1F497D'>That article has conclusions that really have to be taken with a grain of salt. When it was published there was a flurry of notes passed around.</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=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>It leaves out the most efficient stoves<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>It cites sources that use different methods of calculating the ‘efficiency’. It mixes the system efficiency and the heat transfer efficiency, two <i>very</i> different numbers, and treats them as the same thing (by not examining the sources).<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>It advocates using ‘advanced’ stoves but compares them with technologies that are aged, meaning the assumption is there are no advanced electric or other systems.<o:p></o:p></span></p><p class=MsoListParagraph><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'>So I too recommend the article. For cooking the bottom line claims are a bit fishy and ‘yeah, well, if we correct for this and that error’….<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'>But for space heating the concept is spot-on. It is much more system efficient to create primary heat locally. It also can produce less total emissions of anything you care to mention.<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'>It is a good article to challenge yourself on whether the comparisons are made fairly or not. If you compare the energy in the total fuel consumed in one system with the energy in the heat transferred to the pot in another, how do you know if one is better than the other?<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'>Thanks for the link.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>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><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>Stovers,<br><br>I highly recommend everyone see this article on <o:p></o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal>Well-Tended Fires Outperform Modern Cooking Stoves<o:p></o:p></p></blockquote><p class=MsoNormal><a href="http://www.lowtechmagazine.com/2014/06/thermal-efficiency-cooking-stoves.html">http://www.lowtechmagazine.com/2014/06/thermal-efficiency-cooking-stoves.html</a> <o:p></o:p></p><div><pre>Very well done, with references, and providing some awesome quotations for future <o:p></o:p></pre><pre>articles by others. <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>1.<o:p></o:p></pre><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre>In fact, an electric cooking stove is only half as efficient as a well-tended <o:p></o:p></pre></blockquote><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre>open fire, while a gas hob is only half as effective as a biomass rocket stove. <o:p></o:p></pre></blockquote><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre>And even though indoor air pollution is less of an issue with modern cooking stoves, <o:p></o:p></pre></blockquote><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre>research indicates that pollution levels in western kitchens can be surprisingly high. <o:p></o:p></pre></blockquote><pre><o:p> </o:p></pre><pre>2.<o:p></o:p></pre><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre><span style='font-size:13.0pt'>Improved biomass stoves have double or triple the thermal efficiency of modern </span><o:p></o:p></pre></blockquote><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><pre><span style='font-size:13.0pt'>electric or gas cooking stoves.</span><o:p></o:p></pre></blockquote><pre><o:p> </o:p></pre><pre>3. Best thermal efficiency (out of 9 stove types) is 45% accomplished by Woodgas stove. (on chart).<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>4. It is disappointing that the article repeats data from a 2008 report that is now superceeded, and <o:p></o:p></pre><pre>cites the 2012 PCIA report of data collected by Aprovecho 7 to 8 years earlier (but publication delayed). <o:p></o:p></pre><pre><o:p> </o:p></pre><pre>I hope that many Stovers will read this article from Low-Tech Magazine and make comments.<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>I am sending a separate message (with different Subject line) about delays in finding this <o:p></o:p></pre><pre>article (almost one year after publication) so that the two Subjects have different threads of discussion.<o:p></o:p></pre><pre><o:p> </o:p></pre><pre>Paul<o:p></o:p></pre><pre>Doc / Dr TLUD / Prof. Paul S. Anderson, PhD <o:p></o:p></pre><pre>Email: <a href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</a> <o:p></o:p></pre><pre>Skype: paultlud Phone: +1-309-452-7072<o:p></o:p></pre><pre>Website: <a href="http://www.drtlud.com">www.drtlud.com</a><o:p></o:p></pre><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>