<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>How do you get a sample from hot moist exhaust without whacking out the meter.</div><div>Mine took 30 minutes to recover.</div><div><br></div><div><br>On Oct 27, 2014, at 9:14 PM, Crispin Pemberton-Pigott <<a href="mailto:crispinpigott@outlook.com">crispinpigott@outlook.com</a>> wrote:<br><br></div><blockquote type="cite"><div><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"><meta name="Generator" content="Microsoft Word 15 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
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</o:shapelayout></xml><![endif]--><div class="WordSection1"><p class="MsoPlainText">Dear Lanny<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">That is a very sensible question.<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">IF you take the simplest form of the equation it is <o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText"><u> Measured O<sub>2 </sub> <span style="color:white">s</span><o:p></o:p></u></p><p class="MsoPlainText">21 - Measured O<sub>2<o:p></o:p></sub></p><p class="MsoPlainText"><sub><o:p> </o:p></sub></p><p class="MsoPlainText"><span lang="EN-US" style="mso-fareast-language:EN-CA">If you only have an O2 meter, you can still make a lot of progress. Note the picture of my checking the EA in the large TLUD:<o:p></o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA"><o:p> </o:p></span></p><p class="MsoPlainText"><span style="mso-fareast-language:EN-CA"><image001.png></span><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA"><o:p></o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA"><o:p> </o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA">It is just on the side of the flame where on air from the room can get to the nozzle.<o:p></o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA"><o:p> </o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA">It would have been better it there was a pot on, and the sample taken from the edge of the pot like this:<o:p></o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA"><o:p> </o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA">From experience, it is more difficult to keep the EA to a constant level in a wood stove than for other fuels because it is not as predictable and it evolves its chemical composition unevenly.<o:p></o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA"><o:p> </o:p></span></p><p class="MsoPlainText"><span lang="EN-US" style="color:black;mso-fareast-language:EN-CA">If you can get 100% EA, the O2 reading will be 10.5%. If you plug 10.5 into the formula above you get 100% as the answer. You will start to get smoke and CO in higher concentrations at 50% EA in a wood stove, in almost all cases. At 200% EA which is an O2 reading of 14%, you will again start to lose a lot of combustion efficiency.<o:p></o:p></span></p><p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p><p class="MsoPlainText"><span style="color:black">If you are able to keep the EA between 75 and 150%, a range of 2:1, it will be about as good as it is going to get with whatever architecture you have at the time. At 100% EA held constant, you can play with the architecture and get the CO level down more and more. When it is extremely low, it is likely the PM has also disappeared with steady state combustion.<o:p></o:p></span></p><p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p><p class="MsoPlainText"><span style="color:black">The O<sub>2</sub> reading for 75-150% can be determined by working that formula backwards. It is O<sub>2</sub>= 9 to 12.6%.<o:p></o:p></span></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">A more accurate formula is<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText"><u> Measured O<sub>2</sub> - CO/2 <span style="color:white">s</span><o:p></o:p></u></p><p class="MsoPlainText">21 - (Measured O<sub>2</sub>- CO/2)<sub><o:p></o:p></sub></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">If the CO is high, it makes a significant difference (measurable).<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">There are more sophisticated formulae involving more gasses if you are measuring them.<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">Regards<o:p></o:p></p><p class="MsoPlainText">Crispin<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">For a wood fired cooking stove, burning wood, How much excess air is reasonable and what O2 readings would that be?<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">_______________________________________________<o:p></o:p></p><p class="MsoPlainText">Stoves mailing list<o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">to Send a Message to the list, use the email address <a href="mailto:stoves@lists.bioenergylists.org"><span style="color:windowtext;text-decoration:none">stoves@lists.bioenergylists.org</span></a><o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">to UNSUBSCRIBE or Change your List Settings use the web page <a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org"><span style="color:windowtext;text-decoration:none">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</span></a><o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">for more Biomass Cooking Stoves, News and Information see our web site:<o:p></o:p></p><p class="MsoPlainText"><a href="http://stoves.bioenergylists.org/"><span style="color:windowtext;text-decoration:none">http://stoves.bioenergylists.org/</span></a><o:p></o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText"><o:p> </o:p></p><p class="MsoPlainText">_______________________________________________________<o:p></o:p></p><p class="MsoPlainText">Unlimited Disk, Data Transfer, PHP/MySQL Domain Hosting<o:p></o:p></p><p class="MsoPlainText"> <a href="http://www.doteasy.com"><span style="color:windowtext;text-decoration:none">http://www.doteasy.com</span></a> <o:p></o:p></p></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>Stoves mailing list</span><br><span></span><br><span>to Send a Message to the list, use the email address</span><br><span><a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a></span><br><span></span><br><span>to UNSUBSCRIBE or Change your List Settings use the web page</span><br><span><a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a></span><br><span></span><br><span>for more Biomass Cooking Stoves, News and Information see our web site:</span><br><span><a href="http://stoves.bioenergylists.org/">http://stoves.bioenergylists.org/</a></span><br><span></span><br></div></blockquote></body></html>