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Dear Paul</div>
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As I am presently designing large cooking stoves for Uganda the question is relevant and I may be able to provide a couple of insights. </div>
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The schools use stoves up to 300 litres, in the main, not larger as is often the case in Rwanda next door. So the first question is: what is the pot capacity?</div>
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There are a great many boarding schools in Uganda so it is likely that the places mentioned are boarding schools which use far more wood than day schools. High mass institutional brick stoves are common and using them is quite fuel efficient at low power which
covers a lot of meal preparation. Meals are heavy in beans and posho which are longer cooking meals than rice (usually). Is it a boarding school?</div>
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<div class="elementToProof"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Durability is a huge issue with rural institutional stoves. In Rwanda it is common to see a school budget of $200-$500 per term for
rebuilding cracked and broken stoves. Is there any sort of warranty about working life in hours or months that the producer is willing to guarantee? We normally require 2 years free maintenance. </span></div>
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<div class="elementToProof"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Fuel consumption: Fuel saving is a loose term and it should be expressed either as the hot stove fuel efficiency (protocol available
from me) or the cooking of two disparate meals such as rice and beans (very short and very long).
</span><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">What is the proposed design and has it been tested by outside parties for
evaluation? Comparisons are available for checking the fuel consumption per student. That is a good gross metric.</span></div>
<div class="elementToProof"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></div>
<div class="elementToProof"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Pots: At that price the stove should include a modern
pot with lid and handles, sealed into the stove with no leaks around, and a chimney. The pot should have a 3mm bottom at least, and 2mm wall thickness, at least. The bottom corner should be radiused so food does not stick in the bottom corner. All internal
welds have to be smoothed and there must be a pair of handles for easy removal. The pot material must be a food grade SS304 or better. The pots will be approximately 1/3 the price of the stoves you describe. </span></div>
<div class="elementToProof"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></div>
<div class="elementToProof"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">It is quite unnecessary to have a fan and solar panels
to make a high performance wood stove in Uganda. There are designs available to you for the asking. Avoid the designs promoted by the Ministries as they are essentially 1990's Rocket Stoves.</span></div>
<div class="elementToProof"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></div>
<div class="elementToProof"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">There is available for download a presentation made
last on exactly the designs you require. You can have the detailed design in the size you require, from 50 to 300 litres (6 sizes). The link is on my website:</span></div>
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</span></div>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><a href="https://www.newdawnengineering.com/website/library/Papers+Articles/CAU/CAU_FREPDC%20_2023/" id="OWAda3d2910-462a-84bf-93ba-9b43685772d5" class="OWAAutoLink" style="margin-top: 0px; margin-bottom: 0px;">https://www.newdawnengineering.com/website/library/Papers+Articles/CAU/CAU_FREPDC%20_2023/</a> </span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Warning -
it is a large PPT because it contains a lot of videos. Just click on the link and chose where to save it. If someone has a design they want to simulate contact me directly.</span></p>
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</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">A fan is
a substitute for a properly designed chimney. As a school there is usually enough space to have a chimney - about 4.2m tall. A major advantage of a chimney over a fan is that the system is likely to run the combustion at a negative pressure, so there are
few leaks from the stove into the kitchen, if any. If the chimney is effective at removing the fumes from a fan-driven fire, it is likely it would work even better without the fan. Almost all fan-drive fires have too much air entering and exiting the fire
without doing anything useful. </span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">If such a
fan stove exists, I would be interested to see the gas emissions measured at the exit from the stove body. In particular I want to see the CO and oxygen concentrations over the period of a high power heating and lower simmering run, typical of many food cooking
sequences. If the O2 is generally over 12% it is losing heat for nothing, and if it is under 8% it is starving and will be smoky. These guidelines apply whether it is at high or low power. </span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Heat distribution:
as you will sees in the videos, there are serious problems encountered with getting heat distributed over large pots when the combustion chamber is constrained. Does the proposed stove have a "combustion chamber" or just an open or large cylindrical space
below the pot? </span></p>
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</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Charcoal:
Charcoal is a different fuel altogether from wood and requires a different type of combustion chamber and air supply. It is rare to find a stove that burns both fuels "well". </span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">You may be
able to get the Forestry College in the West or CREEC lab in Kampala to evaluate the emissions from the proposed stove. It can be done in the field. If you fail in that regard, I can test it when I am there next. </span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">In the meantime
I would be happy to review any drawings or photos you have been given to estimate what they are trying to sell. </span></p>
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</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Best regards</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Crispin</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Past Sergeant-At-Arms,
Malkerns Rotary Club, Eswatini</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">Senior Technical
Advisor to ESMAP and the Clean Cooking Fund</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">crispinpigott@outlook.com</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br>
</span></p>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="letter-spacing: normal; font-family: Calibri, Helvetica, sans-serif; font-size: 16px; font-weight: 400; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">PS I cannot
see the video as I am in Beijing at the moment but in the coming days I will look.</span></p>
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<div id="divRplyFwdMsg" dir="ltr"><span style="font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>From:</b> Stoves <stoves-bounces@lists.bioenergylists.org> on behalf of Paul Arveson <paularveson@gmail.com><br>
<b>Sent:</b> November 27, 2023 8:57<br>
<b>To:</b> Discussion of biomass cooking stoves <stoves@lists.bioenergylists.org><br>
<b>Subject:</b> [Stoves] Rotary project question</span>
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<p>I received this from a friend and would appreciate your comments:</p>
<p>"I received the email below from a Rotary member in Ithaca New York. She has put together an $11,620 project (attached) to pay for Vron Engineering of Kampala, Uganda, to build four fuel-efficient stoves at schools in Gulu, Uganda, enhanced with a PV-powered
fan to regulate the cooking temperature. Vron Engineering claims their unit reduces firewood or charcoal use by 80%. <a href="https://www.youtube.com/watch?v=4SyWCc-EGis" id="OWA334788af-ed4f-397d-b9b0-373b704fa959" class="x_moz-txt-link-freetext OWAAutoLink" shash="ubZEKePtRqsxwwx9Fht5M++ihNRixSl8RpIxk8AsI1rE+0J6TZT9gAj52Ltsb4E+skIAv6356ZPo54tv+aU/B6l+nEMX6alVMfiGmRmc0EXXGfTH9aM217Pc6SMZEMX8q/2OeJn2uyu380Q5loaRAMUe/BlM1dKE+k/PW7nY1Ns=" originalsrc="https://www.youtube.com/watch?v=4SyWCc-EGis" data-auth="Verified" style="margin-top: 0px; margin-bottom: 0px;">https://www.youtube.com/watch?v=4SyWCc-EGis</a>.
The Rotary presentation is very professional, but my unscientific mind is skeptical. I know that clean cookstoves reduce firewood use, but it seems doubtful that adding a PV panel, battery and fan would further reduce fuel use. And without the PV panel,
it seems excessive to spend $11,000 to demonstrate that clean cookstoves (with stovepipes) actually save fuel—something everyone already knows. Your thoughts?"</p>
<p class="elementToProof">Paul Arveson</p>
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