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Dear Julien</div>
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Muhammad confirmed in a personal message that indeed his stove has a 1.25 Watt fan. I was not able to see that video as YouTube is blocked in the countries I am visiting at the moment. Also Google things are blocked in China, so I didn't see that link either. </div>
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I take your point about the fan, however the six stoves I was working on these past two weeks are all natural draft and the draft is fan higher than the little fans. The implication is that a chimney is a form of 'fan' and generalisations don't apply. </div>
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More important than the division is how the stove functions internally. The proper mixing of fuel gas and air is obviously critical. </div>
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Yesterday we completed (almost) a stove based the GTZ7 with a version number 7.6 made with a steel shell and 19 bricks that form all the internal structures‎. It provides excellent mixing without a "cone" but does have a choke point through which everything
must pass. It is a natural draft cross-draft stove with an extremely simple layout and very low emissions. </div>
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There is basically no visible smoke from five minutes after ignition for the next 6 hours or more. The combustion efficiency was 99.8% and has huge cooking and heating power. The performance is much more important than its classifications. </div>
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The design will be provided as time permits along with the other models that passed muster. We made four basic designs and six versions total. These will now go for focus group evaluation. </div>
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Regards </div>
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Crispin in Dushanbe</div>
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<div>Hello all;<br>
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If Nurhuda's stove in his YouTube video is a natural draft stove, then I stand corrected. Perhaps he can set us straight, because it looks like a forced draft flame, and a see what looks like a wire at the bottom of the stove.
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Regardless, the warning stands that research on forced draft burners has limited analogies for natural draft burners. I will elaborate in a seperate email when I discuss what I think of the CSU presentations at ETHOS.<br>
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<div>Back on this topic. If there is a downward flow of gasses at low power in a ND-TLUD burner then that is a good thing because uncombusted syngas will not escape up the middle.
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Cheers,<br>
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Julien<br>
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<div dir="ltr">Julien Winter<br>
Cobourg, ON, CANADA<br>
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