<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>Crispin and list: See below<br><br><hr id="zwchr"><b>From: </b>"Crispin Pemberton-Pigott" <crispinpigott@gmail.com><br><b>To: </b>"Stoves" <stoves@lists.bioenergylists.org><br><b>Sent: </b>Wednesday, August 21, 2013 3:38:07 PM<br><b>Subject: </b>Re: [Stoves] Excess air<br><br>Dear Ron<br><br>It is not about scale, it is about wrong answers. I gave real life examples of what happens when conditions are not what a formula-writer expects. <br> <b>[RWL: Can you remind where those "real-life examples" are?</b><br><br>EA is a calculated value. If the calculation is incorrect then there is a systematic error in the reported value which would mislead the tester. <br> <b>[RWL: In my world EA is much more a measured value. Who do you know in the stove world who has any idea what the airflow is in their most detailed measurements? I didn't see it at the stove camp - calculated or measured.</b> <b> I do know measured air flow is part of the few doctoral dissertations I have seen in this area.</b><br><br>So we should use the correct formula. <br> <b>[RWL: I agree that one can get more detailed in presenting measured combustion efficiency. Requiring a prior computation on the fuel characteristics that go into an EA prediction and then comparison still seems like overkill - partly for scale reasons. But I will re-look at what you wrote if you tell me where to look. But I repeat, if you gave me the most perfect computation of an EA for any stove, I don't know how to use that data for improving the stove, except in a very general way. Too many interactions of too many parameters. I'm in favor of trusting measured values. ]</b><br>That's all.<br> <br>Regards<br>Crispin<br>From BB9900<br><br>-----Original Message-----<br>From: rongretlarson@comcast.net<br>Sender: "Stoves" <stoves-bounces@lists.bioenergylists.org><br>Date: Wed, 21 Aug 2013 21:32:10 <br>To: Philip Lloyd<plloyd@mweb.co.za><br>Reply-To: Discussion of biomass cooking stoves<br> <stoves@lists.bioenergylists.org><br>Cc: Discussion of biomass cooking stoves<stoves@lists.bioenergylists.org><br>Subject: Re: [Stoves] Excess air<br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://stoves.bioenergylists.org/<br><br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://stoves.bioenergylists.org/<br><br></div></body></html>