<html><head></head><body bgcolor='#FFFFFF' style='font-size:12px;background-color:#FFFFFF;font-family:Verdana, Arial, sans-serif;'>Dear Steve, (Dear George in the Jungle!)<br/>Both engineers explained things in terms that a careful reading by this non-engineer made the differences transparent. Ze Tschermanns vould call Steve's usage "Pi mal Daumen" oder "Über'n Daum peilen" both of which try to take into account that there is a relatively wide variance in thumbs, kind of like "rules of thumb", but maybe somewhat more precise than that. For purposes of the argumentation in the present context the difference in the reckoned results is way less than the guesstimated increase in efficiency that Roger was projecting on his assumption that the Mongolian furnaces were putting over 80% waste heat up the chimneys. So, if we just take the avg. of the two calcs... ;-)<br/>Hope you're all having a great day.<br/>regards,<br/>Ron<br/>w<br/>h<br/><br/><br/><br/><blockquote style="border-left: 2px solid blue; margin-left: 5px; padding-left:5px; padding-top:5px;"><hr/><b>Von:</b> "Steve Taylor" <steve@thetaylorfamily.org.uk><br/><b>Gesendet:</b> Jul 27, 2011 11:25:09 AM<br/><b>An:</b> "Discussion of biomass cooking stoves" <stoves@lists.bioenergylists.org><br/><b>Betreff:</b> Re: [Stoves] WorldStove replies to BioFuelWatyche's latestimprecisereporting of facts.<br/><br/><br/><br/><div class="gmail_quote">On 27 July 2011 09:54, George Riegg Gambia <span><<a href="mailto:icecool@qanet.gm">icecool@qanet.gm</a>></span> wrote:<br/><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div><font face="Arial">Hi Steve / Crispin / Roger of Fireside</font></div><div> </div><div><font face="Arial">I'm another of these guys who just hasn't got the tech. language or knowledge so I rely on our experts here and I just try to understand and comprehend.</font></div><div> </div><div><font face="Arial">Looking at Crispin's and Steve's posts about 4 hours apart addressing just about the same topic explaining to Roger the ins and outs of ...... call it energy efficiency / need/ release...... I can understand that Roger is getting confused watching this group.</font></div><div> </div><div><font face="Arial">I see 2 explanations using different methods and by having to make assumptions I accept that the results may vary to a certain degree. But Steve, to say that 5 lb "just about" are 2 kg (it's actually "about" 2.27 which is a 10 % difference which is when multiplied up ALOT).</font></div><div> </div><div><font face="Arial">I really haven't got the time to do alot copy and pasting here but you both use different base figures to calculate the same thing and OF COURSE end up with totally different results:</font></div><div><font face="Arial">Crispin 2.68 hrs at 100 % efficiency</font></div><div><font face="Arial">Steve 1.6 hrs (efficiency not declared)</font></div></div></blockquote><div><br/><br/>George,<br/>I am a professional engineer: My calcs here started as a "wet finger in the air" , or as we call it in the UK, a "fag packet" calculation..... ;-)<br/><br/>That I am less than 100% off Crispin's nuanced calcs, based on actual field measurements I would call bloody nearly miraculous....<br/><br/>The maths scales linearly, for the weight, so my 5kW burn would actually take 1.76 hours - I hate using two places of decimals for this exercise....<br/><br/>Steve</div></div><div id="avg_ls_inline_popup" style="visibility: hidden; left: -5000px; position: absolute; z-index: 9999; padding: 0px; margin-left: 0px; margin-top: 0px; overflow: hidden; word-wrap: break-word; color: black; font-size: 10px; text-align: left; line-height: 130%;"> </div></blockquote></body></html>