<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 14 (filtered medium)"><style><!--
/* Font Definitions */
@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:0mm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
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;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0mm;
margin-bottom:.0001pt;
font-size:10.5pt;
font-family:Consolas;
mso-fareast-language:EN-US;}
p.MsoNoSpacing, li.MsoNoSpacing, div.MsoNoSpacing
{mso-style-priority:1;
margin-top:5.0pt;
margin-right:0mm;
margin-bottom:5.0pt;
margin-left:0mm;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
p.MsoNoSpacingCxSpFirst, li.MsoNoSpacingCxSpFirst, div.MsoNoSpacingCxSpFirst
{mso-style-priority:1;
mso-style-type:export-only;
margin-top:5.0pt;
margin-right:0mm;
margin-bottom:0mm;
margin-left:0mm;
margin-bottom:.0001pt;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
p.MsoNoSpacingCxSpMiddle, li.MsoNoSpacingCxSpMiddle, div.MsoNoSpacingCxSpMiddle
{mso-style-priority:1;
mso-style-type:export-only;
margin:0mm;
margin-bottom:.0001pt;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
p.MsoNoSpacingCxSpLast, li.MsoNoSpacingCxSpLast, div.MsoNoSpacingCxSpLast
{mso-style-priority:1;
mso-style-type:export-only;
margin-top:0mm;
margin-right:0mm;
margin-bottom:5.0pt;
margin-left:0mm;
mso-add-space:auto;
font-size:11.0pt;
font-family:"Arial","sans-serif";
color:#1F497D;}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:Consolas;}
span.EmailStyle20
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
.MsoPapDefault
{mso-style-type:export-only;
mso-margin-top-alt:auto;
mso-margin-bottom-alt:auto;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></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 lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear Testing Friends and Appealing to Peter Verhaart for comment<span style='mso-fareast-language:EN-CA'> (because you were there!)<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>I have been looking over the history of stove testing and it is compelling that the HTP was used for reporting stove performance as early as 1982-3. There are a number of references to it in <a href="http://www.cookstove.net/others/fuel-economy.html">http://www.cookstove.net/others/fuel-economy.html</a> with a number of citations from Prasad and Verhaart as well as Piet Visser.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>There are some Sankey diagrammes and also inherent heat flows. These are useful for determining stove performance in a way that allows useful predictions of field performance to be made based on laboratory tests. Alex, See Fig 12 and 13. Is that what you have in mind for system analysis? Is there software or a function in Excel that can produce that automatically? It could be built into a stove design tool.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>I am attaching some performance curves produced created from a set of more than 80 tests of three stoves. The relationship between power and pot size is clearly visible for each stove. If you want to know how it will cook your favourite ‘burn cycle’ you can make a calculation. I am suggesting this is a useful extension of the good works done in Eindhoven.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>The advantage we have these days is that getting precise emissions measurement is much easier, as is logging mutiple sets of data in real time. The resulting displays are easily generated and optimal conditions identified quickly.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>So my question is how did we go from conducting really good test and stove analysis with really valuable heterogeneous characterisations in the early 1980’s to a simplistic water boiling test in 2012? It is clear from the works pouring out of Iowa State for the past 5 years that WBTs are not helping us much in providing useful information – nothing like what we used to get before and what we an get now from heterogeneous tests.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>So my question to Peter Verhaart is, what do you think about the current state of affairs? How do we recover from it?<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Grant B-T, if you have time, what are we going to do to revive testing to the point that a programme manager can make an informed choice about stoves before rolling something out? I am sure you know the systematic error level in the WBT’s is over 30%.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-CA'>Dr Nate Johnson, you have beat your head against this wall and surely have some advice to take us forward. The industry is getting stuck even as the funding available for stove projects grows by the millions. Never has so much stove money been directed by so little meaningful information on the performance of the products being promoted. This has to change. In fact it has to be restored to its former glory using the new tools and understanding that has developed in the intervening years.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Interestingly there is a reference at the very end of the article at <a href="http://www.cookstove.net/others/fuel-economy.html">http://www.cookstove.net/others/fuel-economy.html</a> to the carbon balance method of testing. This is the method used at the SeTAR Centre and it is not an accident. Most EPA-like methods use a hood (or cabinet) and mass (or whole)-flow calculations, though EPA does use carbon balance methods for vehicles. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The issue is precision and accuracy. The systematic errors together with the experimental errors have to be less than 7% to place a stove securely on performance tiers 20% apart. That is basic math. In order to do this in affordable labs, I suggest that it will require a set of single purpose tests performed in an <i>HPT</i> manner. The attached chart is one way to provide that information. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Testing costs a lot. Money is changing hands. There is little point in a lab providing test results that can be challenged if the stoves turn out not to perform in the band claimed. The more complicated and imprecise the assessment task, the greater the potential for failure to perform. Reputations are on the line. We have to provide better quality characterisations of performance (including durability, safety and social acceptance).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Serious stuff.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Regards to all<o:p></o:p></p><p class=MsoNormal>Crispin<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>