<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div style="RIGHT: auto"><SPAN style="RIGHT: auto">Hi all this is Gustavo I´m getting into chimneys, as I was working with Dr. Larry Winiarski I learn that the diameter of combustion chamber has to be equal the diameter of the chimney, but allwas depend on the size of the diameter of the cooking area and if you are not loosing heat in the cooking proces for that reazon what do and work for me is that if a rocket stove has a 4 inches diameter in the area wher you install the chimney I all ways reduce to 1/4 of an inch this will help to hold more heat under the cooking area surface, long time ago I wanto experiment with a Rocket Stove with diferent chimneys to calculate </SPAN><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2664" wd="null">the</SPAN> <SPAN class=hps closure_uid_743731900="2665"
wd="null">optimal</SPAN> <SPAN class=hps closure_uid_743731900="2666" wd="null">diameter</SPAN> <SPAN class=hps closure_uid_743731900="2667" wd="null">and height</SPAN> <SPAN class=hps closure_uid_743731900="2668" wd="null">of</SPAN> <SPAN class=hps closure_uid_743731900="2669" wd="null">the chimney</SPAN><SPAN closure_uid_743731900="2670" wd="null">,</SPAN> <SPAN class=hps closure_uid_743731900="2671" wd="null">I think</SPAN> <SPAN class=hps closure_uid_743731900="2672" wd="null">not from a</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2674" wd="null">scientist point of view a big</SPAN><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2676" wd="null"> diameter loses heat</SPAN> <SPAN class=hps closure_uid_743731900="2679" wd="null">and</SPAN> if is <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2680" wd="null">the chimney is <SPAN class=hps closure_uid_743731900="2818" wd="null">too</SPAN> <SPAN
style="RIGHT: auto" class=hps closure_uid_743731900="2819" wd="null">high</SPAN></SPAN> the <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2684" wd="null">acelacion</SPAN> <SPAN class=hps closure_uid_743731900="2685" wd="null">would affect</SPAN> <SPAN class=hps closure_uid_743731900="2686" wd="null">the</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2687" wd="null">gases</SPAN><SPAN closure_uid_743731900="2688" wd="null">,</SPAN> <SPAN class=hps closure_uid_743731900="2689" wd="null">therefore</SPAN> <SPAN class=hps closure_uid_743731900="2690" wd="null">we would be</SPAN> <SPAN class=hps closure_uid_743731900="2691" wd="null">causing</SPAN> <SPAN class=hps closure_uid_743731900="2692" wd="null">a deficiency in</SPAN> the <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2693" wd="null">use</SPAN> of <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2694" wd="null">the energy produced by</SPAN>
<SPAN class=hps closure_uid_743731900="2695" wd="null">the</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="2696" wd="null">combustion,</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="3715" wd="null">I would like that someone</SPAN> <SPAN class=hps closure_uid_743731900="3716" wd="null">with</SPAN> <SPAN class=hps closure_uid_743731900="3717" wd="null">the right equipment</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="3718" wd="null">put hands on the issue and get</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="3720" wd="null">some</SPAN> <SPAN class=hps closure_uid_743731900="3721" wd="null">controlled tests</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="3722" wd="null">to pass</SPAN> <SPAN class=hps closure_uid_743731900="3723" wd="null">the information</SPAN> to stovers. another thing that<SPAN style="RIGHT: auto" class=hps wd="null"
closure_uid_67291657="4691"> I</SPAN> <SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4692">observe</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4693">is that if the</SPAN> <SPAN class="hps alt-edited" wd="null" closure_uid_67291657="4694">diameter of the chimney</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4695">is smaller than the</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4696">diameter</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4697">of</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4698">the combustion chamber</SPAN><SPAN wd="null" closure_uid_67291657="4699">,</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4700">the heat</SPAN> <SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4701">go to</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4702">the opposite direction</SPAN> <SPAN style="RIGHT: auto" class=hps wd="null"
closure_uid_67291657="4703">of the combustion not folowing to the chimney</SPAN> <SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4704">or</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4705">whether</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4706">there is a</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4707">heat</SPAN> <SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4708">exes not going to the right derection</SPAN><SPAN style="RIGHT: auto" wd="null" closure_uid_67291657="4709">, it's like</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4710">a water container</SPAN> that is <SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4712">overflowing</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4713">by</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4714">which</SPAN> <SPAN style="RIGHT: auto" class=hps wd="null"
closure_uid_67291657="4715">while we add</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4717">water</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4718">at a higher speed</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4719">to</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="4720">the</SPAN> <SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4721">output speed.</SPAN></div>
<div style="BACKGROUND-COLOR: transparent; FONT-STYLE: normal; FONT-FAMILY: times new roman, new york, times, serif; COLOR: rgb(0,0,0); FONT-SIZE: 16px; RIGHT: auto"><SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4721"><SPAN class=hps wd="null" closure_uid_67291657="5405">I</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="5406">said</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="5407">trying to</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="5408">increase the</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="5409">diameter</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="5410">gradually until</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="5411">the correct flow</SPAN> <SPAN class=hps wd="null" closure_uid_67291657="5412">encontral</SPAN></SPAN></div>
<div style="BACKGROUND-COLOR: transparent; FONT-STYLE: normal; FONT-FAMILY: times new roman, new york, times, serif; COLOR: rgb(0,0,0); FONT-SIZE: 16px; RIGHT: auto"><SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4721">check this link is one of my stove, in this case the chimner was a bit to small, until Dr. Winiarki give the idea and keep trying to encrease the diameter gradually until I found the proper flow of gases, this a challange in every new desing.<VAR id=yui-ie-cursor></VAR></SPAN></div>
<div style="BACKGROUND-COLOR: transparent; FONT-STYLE: normal; FONT-FAMILY: times new roman, new york, times, serif; COLOR: rgb(0,0,0); FONT-SIZE: 16px; RIGHT: auto"><SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4721"></SPAN> </div>
<div style="BACKGROUND-COLOR: transparent; FONT-STYLE: normal; FONT-FAMILY: times new roman, new york, times, serif; COLOR: rgb(0,0,0); FONT-SIZE: 16px; RIGHT: auto"><SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4721"></SPAN><SPAN style="RIGHT: auto" class=hps wd="null" closure_uid_67291657="4721"><A href="http://www.youtube.com/watch?v=MQzHBU1CI80">http://www.youtube.com/watch?v=MQzHBU1CI80</A></SPAN></div>
<div style="RIGHT: auto"> </div>
<div style="RIGHT: auto">ps: <SPAN class=hps closure_uid_743731900="4925" wd="null">this is not a</SPAN> <SPAN class=hps closure_uid_743731900="4926" wd="null">scientific commentary</SPAN><SPAN closure_uid_743731900="4927" wd="null">,</SPAN> <SPAN class=hps closure_uid_743731900="4928" wd="null">my work is</SPAN> <SPAN class=hps closure_uid_743731900="4929" wd="null">based on</SPAN> <SPAN class=hps closure_uid_743731900="4930" wd="null">common sense</SPAN> <SPAN class=hps closure_uid_743731900="4931" wd="null">but</SPAN> <SPAN class=hps closure_uid_743731900="4932" wd="null">on some occasions</SPAN> <SPAN class=hps closure_uid_743731900="4933" wd="null">when the problem</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4934" wd="null">is more difficult I tried to get</SPAN><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4935" wd="null"> </SPAN><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4936"
wd="null">profecional advise</SPAN> <SPAN class=hps closure_uid_743731900="4937" wd="null">otherwise</SPAN> I <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4938" wd="null">could</SPAN> <SPAN class=hps closure_uid_743731900="4939" wd="null">not</SPAN> <SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4940" wd="null">get ahead wiht my ideas.</SPAN></div>
<div style="RIGHT: auto"><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4940" wd="null"></SPAN> </div>
<div style="RIGHT: auto"><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4940" wd="null">Thank you</SPAN></div>
<div style="RIGHT: auto"><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4940" wd="null"></SPAN> </div>
<div style="RIGHT: auto"><SPAN style="RIGHT: auto" class=hps closure_uid_743731900="4940" wd="null">Gustavo</SPAN></div>
<DIV style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt">
<DIV style="FONT-FAMILY: times new roman, new york, times, serif; FONT-SIZE: 12pt">
<DIV style="RIGHT: auto" dir=ltr><FONT size=2 face=Arial>
<DIV style="BORDER-BOTTOM: #ccc 1px solid; BORDER-LEFT: #ccc 1px solid; PADDING-BOTTOM: 0px; LINE-HEIGHT: 0; MARGIN: 5px 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; HEIGHT: 0px; FONT-SIZE: 0px; BORDER-TOP: #ccc 1px solid; BORDER-RIGHT: #ccc 1px solid; PADDING-TOP: 0px" class=hr contentEditable=false readonly="true"></DIV><B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Paul Anderson <psanders@ilstu.edu><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> Michal Usowicz <usowicz@mail.usf.edu>; Discussion of biomass cooking stoves <stoves@lists.bioenergylists.org> <BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Saturday, March 23, 2013 5:34 PM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [Stoves] Chimney Project in Madagascar<BR></FONT></DIV><BR>
<DIV style="RIGHT: auto" id=yiv1225406585>
<DIV style="RIGHT: auto">
<DIV style="RIGHT: auto" class=yiv1225406585moz-cite-prefix>Dear Michal, (and Stovers)<BR><BR>I am sending this reply and your message (below) to the 500+ readers of the Stoves Listserv. Any replies from them need to be sent to you also at Michal Usowicz <A class=yiv1225406585moz-txt-link-rfc2396E href="mailto:usowicz@mail.usf.edu" rel=nofollow target=_blank ymailto="mailto:usowicz@mail.usf.edu">mailto:usowicz@mail.usf.edu</A> because you are not subscribed to the Stoves Listserv.<BR><BR>About chimneys, I am not qualified to respond. My only comment is to question the size (and probable expense) of what you are discussing. <BR><BR>Dr TLUD<BR><PRE class=yiv1225406585moz-signature>Paul S. Anderson, PhD aka "Dr TLUD"
Email: <A class=yiv1225406585moz-txt-link-abbreviated href="mailto:psanders@ilstu.edu" rel=nofollow target=_blank ymailto="mailto:psanders@ilstu.edu">psanders@ilstu.edu</A> Skype: paultlud Phone: +1-309-452-7072
Website: <A class=yiv1225406585moz-txt-link-abbreviated href="http://www.drtlud.com/" rel=nofollow target=_blank>http://www.drtlud.com/</A></PRE>On 3/23/2013 7:23 AM, Michal Usowicz wrote:<BR></DIV>
<BLOCKQUOTE type="cite"><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt" class=yiv1225406585MsoNormal><FONT size=3><FONT face=Calibri>Dr Anderson,</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt" class=yiv1225406585MsoNormal><FONT size=3><FONT face=Calibri>I hope that everything is going wonderfully with you and that your TLUDs are still burning!<SPAN> </SPAN>I recently got to Madagascar for Peace Corps service and things have been progressing well.<SPAN> </SPAN>My host family for pre-service training here cooks with wood inside but they are planning to build a chimney and I would like to help them construct a good one.<SPAN> </SPAN>Large diameter (about 3-4 ft) brick chimneys similar to what you may expect to see in US homes are common in the community that my host family is in and I think a brick chimney will be the best solution to ventilating the home in this context.<SPAN> </SPAN></FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt" class=yiv1225406585MsoNormal><FONT size=3 face=Calibri> </FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt" class=yiv1225406585MsoNormal><FONT size=3><FONT face=Calibri>A large diameter, natural draft, brick chimney seems like a straight forward problem but I wanted to make sure that I was not making any mistakes.<SPAN> </SPAN>I thought you may be a good person to ask even though I know this isn’t your exact specialty.<SPAN> </SPAN>I expect the chimney will be about 15-20 ft tall and at least the hearth will have a rectangular cross-sectional area of 3.5x4 ft^2 since that it the current size of my host mother’s fireplace (although I am unsure if my host family will construct the chimney with a taper).<SPAN> </SPAN>It will primarily be made out of clay bricks and mortar.<SPAN> </SPAN>Could you please give me some guidance on the following questions?</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraphCxSpFirst><FONT size=3 face=Calibri> </FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraphCxSpMiddle><SPAN><SPAN><FONT size=3 face=Calibri>1.</FONT><SPAN style="LINE-HEIGHT: normal; FONT-VARIANT: normal; FONT-STYLE: normal; FONT-SIZE: 7pt; FONT-WEIGHT: normal; font-size-adjust: none; font-stretch: normal"> </SPAN></SPAN></SPAN><FONT size=3><FONT face=Calibri><SPAN> </SPAN><SPAN> </SPAN>Is there a good rule of thumb for the minimum chimney height to have good draw from the hearth?<SPAN> </SPAN>The only way that I have to estimate this is using the chimney effect equation (ie flow is proportional to Area, height^0.5) and I found that for practical chimney heights for my situation (ie 15-20 ft) there was not a significant change in the flow rate of the chimney.<SPAN> </SPAN>However, for the equation to apply the chimney needs to be adiabatic, which I think is a bad assumption in this case.<SPAN> </SPAN>Do you think
15 ft will be tall enough or does it need to be taller?</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraphCxSpMiddle><SPAN><SPAN><FONT size=3 face=Calibri>2.</FONT><SPAN style="LINE-HEIGHT: normal; FONT-VARIANT: normal; FONT-STYLE: normal; FONT-SIZE: 7pt; FONT-WEIGHT: normal; font-size-adjust: none; font-stretch: normal"> </SPAN></SPAN></SPAN><FONT size=3><FONT face=Calibri>I do not understand the effects of geometry on chimney draw and was curious if there is a problem with necking down the chimney significantly after the hearth?<SPAN> </SPAN>I suspect that my host family may copy the design of a neighbor’s chimney (since they are hiring the same mason to build theirs) which tapers down asymmetrically (ie the left wall is slanted and the right is straight) after the hearth from about 2x3.5 ft^2 at the base to about 2x1 ft^2 over about 6 ft.<SPAN> </SPAN><SPAN> </SPAN></FONT></FONT></div><FONT size=3
face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraphCxSpMiddle><SPAN><SPAN><FONT size=3 face=Calibri>3.</FONT><SPAN style="LINE-HEIGHT: normal; FONT-VARIANT: normal; FONT-STYLE: normal; FONT-SIZE: 7pt; FONT-WEIGHT: normal; font-size-adjust: none; font-stretch: normal"> </SPAN></SPAN></SPAN><FONT size=3><FONT face=Calibri>Along the lines of the previous question, I am concerned that the rain cap for the chimneys may choke the flow.<SPAN> </SPAN>The rain caps of the chimneys here is a thin slab of concrete set at the top of the chimney with 1-3 bricks at each corner.<SPAN> </SPAN>Do I need to pay attention to the size of the gaps under the rain cap?</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraphCxSpMiddle><SPAN><SPAN><FONT size=3 face=Calibri>4.</FONT><SPAN style="LINE-HEIGHT: normal; FONT-VARIANT: normal; FONT-STYLE: normal; FONT-SIZE: 7pt; FONT-WEIGHT: normal; font-size-adjust: none; font-stretch: normal"> </SPAN></SPAN></SPAN><FONT size=3><FONT face=Calibri>I know if you build the chimney shorter than the apex of the house the chimney effect of the house may overwhelm the effect of the chimney.<SPAN> </SPAN>Do you have any intuition or advice about the height difference between the chimney and the roof apex that is needed to avoid this?<SPAN> </SPAN></FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraphCxSpMiddle><SPAN><SPAN><FONT size=3 face=Calibri>5.</FONT><SPAN style="LINE-HEIGHT: normal; FONT-VARIANT: normal; FONT-STYLE: normal; FONT-SIZE: 7pt; FONT-WEIGHT: normal; font-size-adjust: none; font-stretch: normal"> </SPAN></SPAN></SPAN><FONT size=3><FONT face=Calibri>I feel intuitively that it would be a good idea to minimize the height of the hearth entrance to capture the smoke plume before it spreads but I am not sure if this matters if there is good draw in the chimney.<SPAN> </SPAN>Do you have an opinion on this?</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraphCxSpLast><SPAN><SPAN><FONT size=3 face=Calibri>6.</FONT><SPAN style="LINE-HEIGHT: normal; FONT-VARIANT: normal; FONT-STYLE: normal; FONT-SIZE: 7pt; FONT-WEIGHT: normal; font-size-adjust: none; font-stretch: normal"> </SPAN></SPAN></SPAN><FONT size=3><FONT face=Calibri>Have you ever heard of Rumsford chimneys?<SPAN> </SPAN>I had a construction engineer friend of mine build one in his house and he said that the draw from the chimney was excellent.<SPAN> </SPAN>I was just curious if you had heard of it and if you had an opinion of it.<SPAN> </SPAN></FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.25in" class=yiv1225406585MsoNormal><FONT size=3><FONT face=Calibri>Again I hope that everything is going well with you.<SPAN> </SPAN>I would really appreciate any advice you may be able to give.</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt 0.5in" class=yiv1225406585MsoListParagraph><FONT size=3 face=Calibri> </FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt" class=yiv1225406585MsoNormal><FONT size=3><FONT face=Calibri>Sincerely,</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT>
<div style="MARGIN: 0in 0in 0pt" class=yiv1225406585MsoNormal><FONT size=3><FONT face=Calibri>Michal Usowicz</FONT></FONT></div><FONT size=3 face="Times New Roman"></FONT><BR></BLOCKQUOTE><BR></DIV></DIV><BR>_______________________________________________<BR>Stoves mailing list<BR><BR>to Send a Message to the list, use the email address<BR><A href="mailto:stoves@lists.bioenergylists.org" ymailto="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</A><BR><BR>to UNSUBSCRIBE or Change your List Settings use the web page<BR><A href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org" target=_blank>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</A><BR><BR>for more Biomass Cooking Stoves, News and Information see our web site:<BR><A href="http://www.bioenergylists.org/" target=_blank>http://www.bioenergylists.org/</A><BR><BR><BR><BR></DIV></DIV></div></body></html>