May 1999 Gasification Archive

For more information to help people develop better stoves for cooking with biomass fuels in developing regions, please see our web site: http://www.bioenergylists.org

From Reedtb2 at cs.com Sat May 1 08:45:03 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:19 2004
Subject: Report on Honduran stoves
Message-ID: <1a8c62bf.245c512a@cs.com>

Dear Rogerio and Stovers:

The following may be a cruel joke of fate:
<<
Here in Nicaragua we have just surveyed 2025 urban households (plus 800
being surveyed right now) about fuel uses and preferences. Basicaly, there
is a trend from fuelwood to LPG in the urban area (in average today 50%
uses fuelwood, 30% LPG and 20% fuelwood + LPG), but we are in a transition
phase in which people are using both fuels.
>>
All indications are that the 20th Century will be remembered as the century
of low cost energy in many forms and with little restriction on use. There
are many indications that early in the 21st Century the use of fossil fuels
will exceed production and we'll be in a bidding war for convenient energy.
Guess who loses. Last in, first out. So, just about the time the poorer
half of humanity converts to propane and kerosene the cost will quintuple and
they'll be back in the cold, minus previous skills.

So, it's up to us to come up with better biomass stoves in time for the
fossil fuel crunch.

Yours truly, TOM REED

PS I was puzzled by another comment...

5. LPG is dangerous (explodes)

Maybe the media is conspiring to keep this a secret, but in my experience
propane is extremely safe or we wouldn't use it.

Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From spanish at xel.net Sat May 1 10:22:20 1999
From: spanish at xel.net (spanish@xel.net)
Date: Tue Aug 31 21:36:19 2004
Subject: Guatemalan Highlands,Building stoves
Message-ID: <3.0.3.32.19990501091314.00e52500@xel.net>

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From Reedtb2 at cs.com Mon May 3 09:23:36 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:19 2004
Subject: STOVE CHINA SCOUT
Message-ID: <faea8ba5.245efd57@cs.com>

Dear STOVERS:

I met an amazing person today in church (JUC where Ron Larson also attends -
when he's in town). Her name is Eunice Brock and she was born in China
(missionary parents) about 1915 (?). She has spent her adult life in the
U.S., recently in the Denver area and Ron and I have known her for over a
decade. Several years ago she moved to the Pacific Northwest to be near her
children.

She returned to church today with lots of hugs and kisses. She was in town
for the sale of a large piece of property. She pounced on me to ask if I
knew about solar stoves and renewable energy. She has decided to return to
China to a remote village and set up a school for alternate energy using the
proceeds of the sale. She expects to die there, but appears in great health
and will be able to accomplish a lot. I told her to be sure to come visit my
stove lab here in Golden before she returns for some demonstations of stoves
and fuels.

I asked if she had Email - no. I said that her effectiveness would be
multiplied many times if she could communicate questions and her day-to day
experiences.

I HOPE TO ESTABLISH AN EMAIL LINK IN REMOTE CHINA for her. How difficult is
it to use sattelite E-mail please? For the time being I will attach her to
my Compuserve 2000 account so she can get literate before she leaves.

Other suggestions for stoves in remote China?

Yours truly, TOM
REED
BEF
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From dstill at epud.org Tue May 4 02:50:49 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:19 2004
Subject: Report on Honduran stoves
Message-ID: <002e01be95fc$0656c680$5d0e66d1@default>

Dear Rogerio,

Thanks for the great report on the plancha stove and fuel use in Nicaragua.
I very much agree that getting the harmful smoke out of the kitchen is of
utmost importance. We tried to make the plancha stove a bit more efficient
by adding an insulated combustion chamber/internal chimney and getting
closer contact between hot flue gases and the plancha. But the concept is
the same and I congratulate you and the team that came up with this simple,
inexpensive, and effective stove! I think that this stove might find a lot
of interest in the U.S., too.

I have a question about the plancha itself. How thick is the metal? We are
finding that 1/8" steel wants to warp when it gets hot. How did you deal
with this problem? We notice that thinner metal does not warp in the same
way.

The team from Aprovecho is also introducing stoves with three or four
burners in which fire directly contacts the pots. These stoves are a bit
more fuel efficient but they depend on the pots to block smoke from entering
the room, like the old Lorena. Unlike the Lorena, the new Three Pot Rocket
forces more heat to contact the pots. It also uses natural insulation such
as wood ash.

We look forward to visiting with you and developing stoves together.

Thanks,

Dean Still

From larcon at sni.net Wed May 5 19:55:53 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding Kirk Smith on Pollution measurements
Message-ID: <v01540b03b35660a8481e@[204.131.233.9]>

Stovers:

I have now been back from Ethiopia for two days and will slowly try
to respond to the many messages coming in from my "dump" of a month ago.

The following was a thoughtful, useful response from Kirk Smith
that came in personally off-list. Kirk has OK'd my sending it out to the
full list with some interspersed questions/comments.

Kirk refers to a response on the same subject of April 4 from Kevin
Chisholm, which I will respond to separately.

Again, I thank Alex for carrying out the coordinator duties for the
last month.

Kirk said:

>Ron, as you know there has been alot of work done to develop standard
>methods in this arena. There are basically three methods. We are using
>carbon balance method for our measurements of fuel-stove combinations in
>India and China and the kiln work in Thailand, Brazil, and Kenya.

(Larson): Kirk - can you give a good reference on this
methodology? You have previously reported on some of this new measurement
work - when will it be available for release?

>We have
>also successfully used the chamber method. (See our recent article in
>Environment International - v24,#7,p739, 1998 - for a way to do so using
>the actual village kitchen as the chamber rather than setting up a separte
>one. I can fax it to you, if needed.)

(Larson): I think the best alternative might be sending it
(electronically?) to Alex for inclusion on the stoves web page. Possible?

>The most acurrate method is the
>hood method, as suggested by Kevin, but to be done right it requires fairly
>sophisticated equipment in a lab setting. There is no way I know to do it
>in the field. For a nice description of the method, I suggest you check
>the thesis of Grant Ballard-Tremor, which I believe he has put on his
>website: http://www.energy.demon.nl

(Larson): I agree that Grant's thesis is a very important
contribution and hope others will look it up on his web page.

Has anyone had any success using a hood in the field?

>Just sticking devices above an open solid-fuel fire, however, does not, in
>my experience, result in useful repeatable data, unfortunately. Best/K
>

(Larson): Rogerio. I interpret this last remark from Kirk to mean
that it will be difficult to justify continuing to make the tyoe of open
area pollutant-release measurements that I had reported being done in
Nidaragua. What are your thoughts on how to choose amongst these three
methods?

Stovers: I personally consider Kirk's work on pollutant
measurement procedures to be first rate - and believe we should carefully
pay attention to what he hasto say.

Any other recommendations for Rogerio?

Good to be back and thinking about stoves. I found several good new
stove-iaq research programs in Ethiopia nd will report on those later.
Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From larcon at sni.net Sun May 9 09:58:45 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding John Gulland on (mostly) test stands
Message-ID: <v01540b00b35b39461b6f@[204.131.233.45]>

Stovers - This dialog was initially intended to stay "off-line", but has
gone in directions that seems important to the full list. I apologize to
John for surprising him with this, but don't believe he will mind. It
brings a lot of material in which is pertinent to Rogerio and probably many
others.

>Hi Ron. You wrote:
>>
>> 1. I can't figure out why it got bounced (last month) to
>> myself (and then
>> Alex cleared it a few hours later), Can you see any reason?
>>
>I'm not actually sure what you mean by bounce so I can't help. Other
>messages I've sent to the list seem to just show up like normal, but this
>one was sent by Alex to the list.
>
Background: One (but not both) of John's messages of a month ago was
forwarded by Alex. "Bounce" means that the central computer (in North
Carolina) didn't recognize your name as a list member. It then sends
(bounces) your message on to the list coordinators (in this case to at
least Alex and myself - and maybe still Tom Miles). We see a message such
as:

"BOUNCE stoves@crest.org: Admin request of type /\buns\w*b/i at line 9"

and then we decide whether to send it on (and usually do). When a real
list member has the "bounce", it makes no sense and we try to get it fixed
as it slows down the message and takes us more time. If it happens again,
I (or Alex) will send it on of course, but probably will try again to
figure out what happened with the CREST (or your) computer. Next time I
would probably also contact the CREST operator as well. In your case,
there was no obvious reason (especially at "line 9").

>> 2. You had a great response and I have not yet had a chance
>> to see your
>> web-site. But it appears that you will be recommending a different
>> approach for places like Nicaragua. Any new ideas over the
>> last month or
>> in response to Kirk Smith's note that I forwarded a few days ago? Any
>> other comments from anyone (I am just getting started in this catch-up
>> process)?
>
>Yes, I was interested in Kirk's response and went back to look at it, but it
>is fairly cryptic. Also, my particular interest is vented stoves since I
>detect that is the general direction in CA. Given there is general movement
>in the direction of chimney venting and since a closed combustion chamber
>with flows driven by chimney draft opens many great opportunities for
>development, I think a test stand configuration and general approach of the
>type used in NA is worth a look as a development tool.

Stovers - I read "CA" initially as "California", but am sure John
means "Central America". I believe John is absolutely correct on both
scores - there is a trend in CA toward venting (because of health concerns
and pot cleanliness) and there seems to be no agreement on a proper test
stand. My guess is that the problem is mostly one of lack of funds - but
we still don't have agreement on what is should look like.

>>
>> We need to keep this dialog going and you are a good
>> one to do so -
>> maybe you could comment on Kirk's response. I will be seeing
>> Kirk next
>> month and will try then to get into the topic in greater
>> depth. Right now
>> I am still very much an amateur.
>
>I sense that Kirk has a wealth of knowledge on this subject. I would love
>to have a week with Kirk, Rogerio, yourself, Grant Ballard-Tremore, John
>Crouch and a couple of NA industry buddies. Apply that much 'horsepower' to
>testing issues and you might see some breakthroughs. Speaking of Grant, I
>went back to his thesis and was reminded how impressive that work is. I
>haven't read it all again yet, but the one area it seems weak is the area I
>am most concerned with and that is the fuel load design and fuelling
>protocol. I could be just missing something, though.

Five responses (and I hope others will jump in). 1. Our e-mail
list can facilitate part of the dialog - even though it takes a lot longer.
Obviously I am taking that approach (including violating etiquette rules
and sending this on to the full list).
2. We will have a great chance at the November 2000 stoves
conference that Dr. Karve is setting up in Pune, India.
3. Kirk has told me he will be available and I'm guessing the time
will be in about 30 days. This will be a good chance for anyone on the
list to ask questions (through this list or privately) that they think Kirk
will have some detail on.
4. Grant should jump in - as I guess all of us will echo John's
admiration for Grant's thesis.
5. Can you get more of the NA industry testers (doing this for our
EPA certification reasons) to address this topic?

>>
>> What else can the list do (per your suggestion)?
>
>Find us $50k to finance the jam session I just mentioned! ;

So this again shows why this message had to "go public". I agree
with John. Anyone on the list able to suggest a source. I thiknk John is
probably suggesting a small invited workshop (maybe in Nicaragua or India,
etc) with the funds to mostly offset travel costs for those people who have
already given a lot of thought to stove testing topics (I'm not yet in that
list - but would probably try to show up).

>
<snip on two topics that were off the measurement subject matter>

John (and Wendy: Thanks for your continuing interest.

As a reminder, John and his wife Wendy also traveled to CA this past
spring. Like my wife and I, they had a fantastic experience. All four of
us can recommend the process.

I sure wish the Pune conference were occurring next month. In the absence
of that, we will have to focus on e-mail, I'm afraid.

Other stovers: Any other thoughts on test-stands, venting, etc.?

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From mheat at mha-net.org Mon May 10 08:30:49 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding John Gulland on (mostly) test stands
In-Reply-To: <v01540b00b35b39461b6f@[204.131.233.45]>
Message-ID: <4.1.19990510061807.00acd100@mha-net.org>

At 07:59 AM 09/05/99 -0600, Ron Larson wrote:
(snip)
>Other stovers: Any other thoughts on test-stands, venting, etc.?
>

Hello Ron and fellow stovers:

Further to Kirk's comments, there definitely seems to be a dividing line
between vented and unvented stoves in terms of test methods that are
available and applicable. Although it has been a while since I've read
Grant's excellent thesis, I do recall being impressed by some of the
methodical, low tech methods of gathering very useful data, such as noting
the smell, for example.

One thing I've learned from reading the stove testing literature over the
years, particularly for North American heating stoves, is how critical it
is, in the long term, to have standardized methods. While it is fairly easy
to stick a calibrated CO or CO2 probe in the stack and take a reading,
quantifying smoke is more difficult, partly due to the complex,
semi-volatile nature of the beast. So, for example, there are any number of
PM (particulates, or smoke) test reports from the 1980's that are mainly of
historical interest today because of a lack of completeness in describing
the test methodology. While it is interesting to know that with stove X,
the PM decreases by 25% (+/- 50%) when you change widget Y, that's about
all it is - interesting. Since the PM number is not acquired through a
standardized methodology, or inadequately described, I have no idea whether
it is 50% or 200% of the equivalent EPA M-5 number (today's North American
standard).

That's not to say that non-standardized testing doesn't have its place -
with careful methodology and simple equipment, one can obtain very good
relative smoke data - ie., for stove development work, it is often good
enough to simply be able to compare one burn accurately with another,
without getting a number that is calibrated to an external standard.
However, this means that future workers, trying to build on past efforts,
will get much less mileage out of your data, and your work. This is
because, with smoke, the numbers can easily by +/- 50%, or more, depending
on methodology.

We've had some limited experience in NA in comparing test methods and
calibrating them to the EPA M-5 (dilution tunnel) standard, and it isn't
easy. Even inter-laboratory comparability is shockingly low. For example,
EPA sent a Jotul stove around to the various labs a number of years ago in
order to measure this very thing. This project is keeping a very low profile!

For vented stoves, the most accessible test method for smoke seems to be
the Condar dilution tunnel. It is an ingenious little portable device
developed by the late Dr. Stockton (Skip) Barnett, one of the true pioneers
of stove testing. Alex has built one and is using it, and we have the
instruction document for it online at
http://mha-net.org/msb/docs/condar.PDF (2.3Mb)

It is directly relatable to EPA M-5, so could be used to calibrate other
methods. After getting about 100 tests or so under our belt, we learned to
just look what was coming out of our smokestack, and got pretty good at
estimating what was going on.

The other thing that we learned was that, with a given air supply, the
fueling protocol is the over-riding variable (for masonry heaters, anyway -
I suspect for most other stoves as well). Fuel moisture, fuel sizing
(particularly surface-to-volume ratio), method of stacking, method of
ignition, all were important. Therefore, we concentrated on detailed
fueling descriptions. We developed a protocol that adds about 10 minutes
per test to characterize the fuel load (weighing, measuring, photographing).

In my opinion, one of the most useful tools to own these days is a digital
camera - you can characterize your fueling method, you can take photos of
your burn progression, and you can get all of that visual data online for
other researchers to see, at very low cost beyong the initial investment in
the camera. I'm quite excited by the developments in digital camcorders
these days, as they should make it possible to take a photo of the burn
progression every couple of seconds, or so.

For a simple example of online visual testing data, see
http://mha-net.org/msb/html/lopezc.htm

Best ............ Norbert
----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
Masonry Stove Builders
RR 5, Shawville------- www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From dstill at epud.org Tue May 11 00:55:56 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding John Gulland
Message-ID: <006601be9b6c$26d02120$140e66d1@default>

Dear Ronal, and company,

Thanks for forwarding these messages. I thought that I would add our recent
experience with vented stoves. Aprovecho is helping to build two different
stoves with chimneys in Honduras.

Ten tests of the open fire using students as amateur testers resulted in an
average efficiency of 11.2% Experienced testers can score higher as they can
with stoves. We use 11% as a baseline measure for fuel use. (11% of the
Btu's released from two pounds of wood made it into a pot containing 5
pounds of water.)

Aprovecho has not played very much with vented stoves for a while since
Larry Winiarski, our lead designer, and I experienced chimneys as being too
expensive for most folks we visited. But, chimneys are liked and used in
Honduras. So, we have had a chance to test a few ideas.

Clean pots are also important in certain places in Honduras. The plancha
stove is great because many pots can be heated at once and all the smoke is
transported out of the room. We tried to optimize the plancha by including a
Rocket type combustion chamber/short chimney and by having the hot flue
gases pass directly under the plancha in a small gap.

Unfortunately, the plancha also radiates heat into the room. Wherever a pot
isn't touching the plancha, heat is wasted. The low mass, insulated plancha
stoves that we have been testing are about 17% efficient. Not bad... better
than an open fire and no smoke!

We also looked at Rocket type stove where there are three burners. The pots
sit on top of the burners blocking the smoke which passes out of the
chimney. Small diverters in the second and third burners force the hot flue
gases to scrape against the bottom of the pot. The added draft from the 4'
to 6' high chimney allows greater diversion of the hot flue gases. The
diverters really push heat against the pot bottom! It took days to find a
good diverter design.The low mass version of this stove is around 30%
efficient.

In the third stove, the pots are submerged to the level of the handles in a
partial plancha grill. The three pots are surrounded by skirts that create
an anulus around each pot with a 1/4" gap. Since the hot flue gases contact
the sides as well as the bottom of the pots the efficiency of the low mass
model is around 40%.

The high mass versions, of course, loose heat to the mass and score
substantially lower as mass robs heat from the pots. High mass definately
reduces efficiency in our tests.

Warming several pots at once raises the efficiency of the stove, which is
one of the great plusses of using a chimney.

It's hard to find enough wood ash in certain parts of Honduras when building
hundreds of stoves. So we have been looking again at different types of
combustion chambers. We have noticed the poorer combustion efficiency
typical of uninsulated combustion chambers in which flame heat is absorbed
and cooled. It makes more of a difference that I had remembered! Insulation
and low mass really do seem to be important...

Dean Still
Aprovecho

-----Original Message-----
From: Ronal W. Larson <larcon@sni.net>
To: stoves@crest.org <stoves@crest.org>
Date: Sunday, May 09, 1999 6:55 AM
Subject: Forwarding John Gulland on (mostly) test stands

>Stovers - This dialog was initially intended to stay "off-line", but has
>gone in directions that seems important to the full list. I apologize to
>John for surprising him with this, but don't believe he will mind. It
>brings a lot of material in which is pertinent to Rogerio and probably many
>others.
>
>>Hi Ron. You wrote:
>>>
>>> 1. I can't figure out why it got bounced (last month) to
>>> myself (and then
>>> Alex cleared it a few hours later), Can you see any reason?
>>>
>>I'm not actually sure what you mean by bounce so I can't help. Other
>>messages I've sent to the list seem to just show up like normal, but this
>>one was sent by Alex to the list.
>>
> Background: One (but not both) of John's messages of a month ago was
>forwarded by Alex. "Bounce" means that the central computer (in North
>Carolina) didn't recognize your name as a list member. It then sends
>(bounces) your message on to the list coordinators (in this case to at
>least Alex and myself - and maybe still Tom Miles). We see a message such
>as:
>
>"BOUNCE stoves@crest.org: Admin request of type /\buns\w*b/i at line 9"
>
> and then we decide whether to send it on (and usually do). When a real
>list member has the "bounce", it makes no sense and we try to get it fixed
>as it slows down the message and takes us more time. If it happens again,
>I (or Alex) will send it on of course, but probably will try again to
>figure out what happened with the CREST (or your) computer. Next time I
>would probably also contact the CREST operator as well. In your case,
>there was no obvious reason (especially at "line 9").
>
>>> 2. You had a great response and I have not yet had a chance
>>> to see your
>>> web-site. But it appears that you will be recommending a different
>>> approach for places like Nicaragua. Any new ideas over the
>>> last month or
>>> in response to Kirk Smith's note that I forwarded a few days ago? Any
>>> other comments from anyone (I am just getting started in this catch-up
>>> process)?
>>
>>Yes, I was interested in Kirk's response and went back to look at it, but
it
>>is fairly cryptic. Also, my particular interest is vented stoves since I
>>detect that is the general direction in CA. Given there is general
movement
>>in the direction of chimney venting and since a closed combustion chamber
>>with flows driven by chimney draft opens many great opportunities for
>>development, I think a test stand configuration and general approach of
the
>>type used in NA is worth a look as a development tool.
>
> Stovers - I read "CA" initially as "California", but am sure John
>means "Central America". I believe John is absolutely correct on both
>scores - there is a trend in CA toward venting (because of health concerns
>and pot cleanliness) and there seems to be no agreement on a proper test
>stand. My guess is that the problem is mostly one of lack of funds - but
>we still don't have agreement on what is should look like.
>
>>>
>>> We need to keep this dialog going and you are a good
>>> one to do so -
>>> maybe you could comment on Kirk's response. I will be seeing
>>> Kirk next
>>> month and will try then to get into the topic in greater
>>> depth. Right now
>>> I am still very much an amateur.
>>
>>I sense that Kirk has a wealth of knowledge on this subject. I would love
>>to have a week with Kirk, Rogerio, yourself, Grant Ballard-Tremore, John
>>Crouch and a couple of NA industry buddies. Apply that much 'horsepower'
to
>>testing issues and you might see some breakthroughs. Speaking of Grant, I
>>went back to his thesis and was reminded how impressive that work is. I
>>haven't read it all again yet, but the one area it seems weak is the area
I
>>am most concerned with and that is the fuel load design and fuelling
>>protocol. I could be just missing something, though.
>
> Five responses (and I hope others will jump in). 1. Our e-mail
>list can facilitate part of the dialog - even though it takes a lot longer.
>Obviously I am taking that approach (including violating etiquette rules
>and sending this on to the full list).
> 2. We will have a great chance at the November 2000 stoves
>conference that Dr. Karve is setting up in Pune, India.
> 3. Kirk has told me he will be available and I'm guessing the time
>will be in about 30 days. This will be a good chance for anyone on the
>list to ask questions (through this list or privately) that they think Kirk
>will have some detail on.
> 4. Grant should jump in - as I guess all of us will echo John's
>admiration for Grant's thesis.
> 5. Can you get more of the NA industry testers (doing this for our
>EPA certification reasons) to address this topic?
>
>>>
>>> What else can the list do (per your suggestion)?
>>
>>Find us $50k to finance the jam session I just mentioned! ;
>
> So this again shows why this message had to "go public". I agree
>with John. Anyone on the list able to suggest a source. I thiknk John is
>probably suggesting a small invited workshop (maybe in Nicaragua or India,
>etc) with the funds to mostly offset travel costs for those people who have
>already given a lot of thought to stove testing topics (I'm not yet in that
>list - but would probably try to show up).
>
>>
> <snip on two topics that were off the measurement subject matter>
>
>
>John (and Wendy: Thanks for your continuing interest.
>
>As a reminder, John and his wife Wendy also traveled to CA this past
>spring. Like my wife and I, they had a fantastic experience. All four of
>us can recommend the process.
>
>I sure wish the Pune conference were occurring next month. In the absence
>of that, we will have to focus on e-mail, I'm afraid.
>
>Other stovers: Any other thoughts on test-stands, venting, etc.?
>
>Ron
>
>Ronal W. Larson, PhD
>21547 Mountsfield Dr.
>Golden, CO 80401, USA
>303/526-9629; FAX same with warning
>larcon@sni.net
>
>
>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html
>For information about CHAMBERS STOVES
>http://www.ikweb.com/enuff/public_html/Chamber.htm
>

From elk at net2000ke.com Tue May 11 01:59:03 1999
From: elk at net2000ke.com (Elsen Karstad)
Date: Tue Aug 31 21:36:19 2004
Subject: Vendors Waste Briquettes - Update
Message-ID: <199905110601.JAA02404@net2000ke.com>

From Reedtb2 at cs.com Tue May 11 12:36:20 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:19 2004
Subject: Top burning in conventional stoves
Message-ID: <1776bb3a.2469b66b@cs.com>

Dear Stovers...

I recently asked whether top burning (inverted downdraft gasification,
charcoal making) combustion would work in any of the conventional wood stoves
to reduce emissions, smooth out heat delivery and make charcoal. Top burning
is the only new twist on stoves in 10,000 years!

I have had zero response. Did the message miscarry? Is there no one out
there that owns a conventional stove that he/she could try it out in?
Whatsamataa?

TOM REED BEF

In a message dated 5/10/99 10:58:59 PM Mountain Daylight Time,
dstill@epud.org writes:

<<
Thanks for forwarding these messages. I thought that I would add our recent
experience with vented stoves. Aprovecho is helping to build two different
stoves with chimneys in Honduras.

Ten tests of the open fire using students as amateur testers resulted in an
average efficiency of 11.2% Experienced testers can score higher as they can
with stoves. We use 11% as a baseline measure for fuel use. (11% of the
Btu's released from two pounds of wood made it into a pot containing 5
pounds of water.)
>>

4/28/99
To: dstill@epud.org, stoves@crest.org

Dear Dean et AL:

I am glad to see stoves developed in the 1980s being used for the desparate
victims of Huricane Mitch and other users.

However, I wonder how many people have tried TOP LIGHTING these stoves.
Spread some dry kindling on top, preferably soaked in vegetable or animal
fat, alcohol or kerosene and light the fire.

If you do this the stove takes on the nature of a gasifier (I call it an
"inverted downdraft gasifier"; Ron Larson likes to call it a charcoal making
stove, others call it top burning. Each blind man to his own elephant
appendage.)

The fire works its way down through the layers of fuel and the gases come to
the surface by natural convection and are burned in ambient air. If there is
too limited access to ambient above the fire, the fire will be rich, but not
as rich as with conventional bottom lighting.

Bottom lighting releases the 80% volatile component of the wood in the first
25% of the burn and there is usually not enough air to burn it. Then the
charcoal burns at reduced levels the remainder of the time. With top
lighting the fire progresses steadily downward, releasing a constant supply
of gas which burns above the charcoal. After the volatiles are all burnt,
the bottom air burns the charcoal and continues to heat at a lower level.

I am not familiar with all the stoves you mention, but I hope you will try a
few runs on each and let us know what happens.

Yours truly, TOM REED
BEF
Stoves List SPONSORS and ARCHIVES:
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http://www.ikweb.com/enuff/public_html/Chamber.htm

From shayden at NRCan.gc.ca Tue May 11 13:42:08 1999
From: shayden at NRCan.gc.ca (Hayden, Skip)
Date: Tue Aug 31 21:36:19 2004
Subject: Combustion & Global Climate Change - CC99
Message-ID: <31EC3D073B34D111BC6000805FBE3A8A77679D@S0-BCC-X1>

Hi Folks:

There is an important conference, Canada's Climate Change Challenge
(Combustion Canada 99 - "CC99") coming up in 2 weeks in Calgary, which would
be most interesting and useful to you.

The conference plenary comprises 11 key government and industry officials,
who will bring you up to date on Canada's efforts to meet the Kyoto
Protocol, and provide their perspective on the policies, priorities and
market drivers to move Climate change technologies. International
developments on Emissions Trading and the Clean Development Mechanism will
also be addressed.

The conference technical sessions have 90 technical papers addressing the
latest developments in Greenhouse Gas technologies and the efforts being
pursued in the upstream oil and gas (flaring), industrial, electrical
utility, transportation and residential/commercial markets, as well as key
developments on increasing the use of biomass in Canada's energy mix and the
latest developments on CO2 capture and disposal from industrial processes
and electricity generation.

Canada's commitment to Greenhouse Gas reductions will have a major influence
on Canada's future electricity production. What role will natural gas play?
How can DSM have a role? Where can major gains be made in the
residential/commercial sector? Learn how energy efficiency initiatives led
by large scale combined heat and power installations for power production
with district heating, industrial scale co-generation, and small and micro
scale co-generation could completely change Canada's technology
infrastructure for the production of electricity from hydrocarbon fuels.
What are the technology options for existing power plants? How can modeling
help you to make the right decision? What other sectors offer major CO2
reductions?
Combustion 99 is focused on answering these questions.

You should be able to come out of this conference with new perspectives on
the role of technology in effecting climate change solutions, and how you
might become profitably involved in such activities.

For further information, see the CC'99 home page on the web at

or contact the Conference Coordinator at (613) 236-6222, Fax (613) 236-6850.

Hope to see you in Calgary,

Skip
Skip Hayden, Conference Chair
ACT-CETC-ETB
1 Haanel Drive
Ottawa, Canada K1A 1M1
Tel: (613) 996-3186; Fax: (613) 992-9335
e-mail: skip.hayden@nrcan.gc.ca

From Reedtb2 at cs.com Thu May 13 08:44:44 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:19 2004
Subject: Top burning in conventional stoves
Message-ID: <2ca87c74.246c2349@cs.com>

Dear Kevin:

Thanks for your excellent reply, particularly the last sentence.

In stoves it is necessary to understand the principles, but it is also
necessary to test, test test. So I hope that those who are working with
conventional stoves will try top ignition.

You mention midpoint air entry, but don't most stoves have bottom air entry?

I have just redesigned our simplest two can stove and we are cooking indoors
on it daily in VIVIAN's kitchen. I'll report soon, but I'm going to
TEST-TASTE first. "The proof of the cooking lies in the eating".

Onward, TOM REED
BEF
In a message dated 5/11/99 2:20:35 PM Mountain Daylight Time,
kchishol@fox.nstn.ca writes:

<< Dear Tom

The success of top burning in a conventional wood stove is very dependant on
the
"fresh air inflow pattern when the fire is operating."

If the effective air entry point was low in the stove, then the effect would
probably be one of "top burning" as the initial charge of wood burned down,
but
when it came time to refuel, new wood would have to be added on top of the
existing fire, and that would effectively end the top burning process.
Continued
firing under the new wood would generally tend to produce more volatiles
that the
"low" air supply could burn to completion.

If the effective air entry point was "high" in the stove, top burning would
occur
initially, and on refuelling it is likely that there would be enough
"overfire
air" effect to result in a somewhat better burn than would occur with a stove
having a low air entry point. However, because the main combustion occurred
below
the fuel, its liberated heat would tend to cause more volatiles to be evolved
from the wood than could be burned within the wood. If these volatiles were
still
above their ignition point when they reached the "overfire air" then they
would
tend to burn to completion, or at least to the point where there was no free
oxygen.

Configuring a stove to give "correct air flow patterns" is not a trivial
matter.
Additionally, it is not necessarily easy to visualize exactly how the air
flow
patterns will develop. My guess is that with a variety of conventional
stoves, a
variuety of results would be attained.

Kindest regards,

Kevin Chisholm
>>
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From Reedtb2 at cs.com Thu May 13 08:45:13 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:19 2004
Subject: Top burning in conventional stoves
Message-ID: <3e8c8991.246c234a@cs.com>

Dear Dean:

Thanks for your reply.

Lighting stoves and running stoves are two different ballgames, but I'm
surprised that major league player like Alex didn't succeed.

Ron Larson uses pine needles in this neighborhood and is horrified when I use
a propane torch. So, I have recently been soaking charcoal from previous
runs in volatile fluids. My preference for a cheap fire start is isopropyl
or ethyl alcohol, so far. I put one monolayer on top of the fuel bed.

1) It gives a high heat rate for first 2 minutes

2) It gives a nice blue flame

3) It establishes the charcoal bed necessary for top down combustion.

I believe that lighter fluid, diesel or kerosene would work as well, but I'm
prejudiced against the smell. Probably bacon fat, vegetable oils OK too.
So, I'll report as I go along.

Onward.. TOM REED BEF

From kchishol at fox.nstn.ca Thu May 13 10:18:40 1999
From: kchishol at fox.nstn.ca (Kevin Chisholm)
Date: Tue Aug 31 21:36:19 2004
Subject: Top burning in conventional stoves
In-Reply-To: <2ca87c74.246c2349@cs.com>
Message-ID: <373ADFCB.496B73D6@fox.nstn.ca>

Dear Tom

I'm glad you found my comments helpful.

Reedtb2@cs.com wrote:

> Dear Kevin:
>
> Thanks for your excellent reply, particularly the last sentence.
>
> In stoves it is necessary to understand the principles, but it is also
> necessary to test, test test. So I hope that those who are working with
> conventional stoves will try top ignition.
>
> You mention midpoint air entry, but don't most stoves have bottom air entry?

The newer stoves with a glass front are generally "top aired", in a very clever
manner: They are designed such that as the air enters the stove, it "floods down
over the inside of the glass" and this keeps smoke from contacting the glass,
condensing, and leaving a tar deposit which bakes on.

In such a stove, it would perhaps be more likely that at least a portion of this
air could be consumed as secondary air at the top of the fuel supply, as the
partially burned products of combustion poke through the fuel bed.

Kindest regards,

Kevin Chisholm

From woodcoal at mailbox.alkor.ru Thu May 13 11:03:44 1999
From: woodcoal at mailbox.alkor.ru (Woodcoal)
Date: Tue Aug 31 21:36:19 2004
Subject: fw: 6th BSCLWC
Message-ID: <01be9d36$a7102300$LocalHost@22>

10.05 1999 21:39
Fw: 6th BSCLWC

ligsymp@faenquil.br to: rmarkenol@aol.com

>Dear colleague,
>
>We would like to officially announce the 6th Brazilian Symposium on the
>Chemistry of Lignins and Other Wood Components.
>
>This year all the information about the Symposium can be found in the
>INTERNET. The Symposium home page can be accessed at
>http://www.faenquil.br/symposium/symposium.htm
>
>The main topics of the sessions, the instructions about how to prepare and
>send the abstracts, as well as some dates and deadlines, are already
>available. As frequently as possible the home page will be updated.
>
>We would be very grateful if you could help us to pass on information about
>this meeting to other researchers that to your knowledge might have
>interest in this area.
>
>We are sure that with your cooperation the meeting will be very well
>attended.
>
>Sincerely yours,
>
>Flávio Teixeira da Silva
>President of the Symposium
>
>
>
>----------
>
>

From larcon at sni.net Thu May 13 12:22:05 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding Eliz. Bates on: Smoke & health
Message-ID: <v01540b00b360907d5019@[204.131.233.21]>

In a "bounced" message, list member Elizabeth Bates of ITDG asked for help
in Kenya (Elsen Karstad please take note):

Dear Stove network members

This topic is not a 'follow on' of the previous discussions, but is
closely associated with the work being done on stoves. In this case,
we are hoping to install the best interventions that are currently
available, rather than looking to the future, so we would like to
know of stoves which are already 'up and running with some
success in situ.

Intermediate Technology Development Group (ITDG) is at present working
on a project in Kenya looking at appropriate interventions for
alleviating household smoke in two communities, one in Kisumu, West
Kenya, and the other at Kajiado, some 100Km south of Nairobi. Most
homes in both communities use traditional three-stone fires. The
Kisumu kitchens are usually separate from the house, are mud-built and
the roof is thatch. In Kajiado, a Maasai community, the stove is
central to the main body of the room. The houses are traditional in
form, although in many instances the roof height has been raised to
about 1.8 metres, and there is a ferrocement skin topping the roof,
which is of round poles, twigs, grass and a mud/cowdung render.

If you have knowledge of either stoves with smoke hoods, or chimney
stoves, which you know have proved successful in similar situations,
please could you let us know. There has been no real tradition of
smoke extraction in these areas, so it is difficult to build on
existing knowledge. The communities are already actively involved in
this project, and we would like to present viable technologies from
which they can determine which would be the most appropriate for their
particular needs.
Elizabeth Bates
Email: elizabethb@itdg.org.uk
Intermediate Technology
Schumacher Centre for Technology and Development
Bourton Hall
Bourton-on-Dunsmore
Warwickshire
CV23 9QZ
Tel:+44-1788 661100
Fax:+44-1788 661101

Url: http://www.oneworld.org/itdg
Intl: http://www.itdg.org.pe
Company Reg No 871954, England
Charity No 247257

From kchishol at fox.nstn.ca Thu May 13 13:44:11 1999
From: kchishol at fox.nstn.ca (Kevin Chisholm)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding Eliz. Bates on: Smoke & health
In-Reply-To: <v01540b00b360907d5019@[204.131.233.21]>
Message-ID: <373B0FFB.2D5B46E6@fox.nstn.ca>

Dear Elizabeth

While it does not answer your question directly, the following "rules of
thumb" for hood design may be helpful to you.

1: Assume that smoke and fume will rise vertically, and size the hood to catch
it.
2: Measure the open perimeter of the hood
3: Air flow for good fume capture should be about 100 cubic feet per minute,
per foot of open perimeter of the hood.

Thus, a 3'x3' hood, open on 4 sides will require about 1,200 cfm of air flow
to effectively capture the fume. By locating the hood against a back wall, the
open perimeter is reduced to 9', thus reducing the air flow requirements by
300 cfm. If the sides are "half enclosed" by bring sheet metal out 1-1/2 feet
from the back on each side, the open perimeter is reduced to 6', reducing air
flow requirements to 600 cfm, but still giving good access.

While 600 cfm is a small flow for a fan, it is a significant flow for a short
chimney and low temperature air. Hopefully, the importance of making the hood
as small and as enclosed as possible is well illustrated.

Kindest regards,

Kevin Chisholm

Ronal W. Larson wrote:

> In a "bounced" message, list member Elizabeth Bates of ITDG asked for help
> in Kenya (Elsen Karstad please take note):
>
> Dear Stove network members
>
> This topic is not a 'follow on' of the previous discussions, but is
> closely associated with the work being done on stoves. In this case,
> we are hoping to install the best interventions that are currently
> available, rather than looking to the future, so we would like to
> know of stoves which are already 'up and running with some
> success in situ.
>
> Intermediate Technology Development Group (ITDG) is at present working
> on a project in Kenya looking at appropriate interventions for
> alleviating household smoke in two communities, one in Kisumu, West
> Kenya, and the other at Kajiado, some 100Km south of Nairobi. Most
> homes in both communities use traditional three-stone fires.

....del....

From krksmith at uclink4.berkeley.edu Thu May 13 16:00:42 1999
From: krksmith at uclink4.berkeley.edu (Kirk R. Smith)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding Eliz. Bates on: Smoke & health
In-Reply-To: <v01540b00b360907d5019@[204.131.233.21]>
Message-ID: <4.1.19990513130312.00cd7750@uclink4.berkeley.edu>

Useful. Many areas in need of smoke reduction do not have reliable
electricity, however, and may need to rely on natural draft. Does anyone
have experience in designing natural draft hoods?/K

At 02:46 PM 5/13/99 -0300, Kevin Chisholm wrote:
>Dear Elizabeth
>
>While it does not answer your question directly, the following "rules of
>thumb" for hood design may be helpful to you.
>
>1: Assume that smoke and fume will rise vertically, and size the hood to catch
>it.
>2: Measure the open perimeter of the hood
>3: Air flow for good fume capture should be about 100 cubic feet per minute,
>per foot of open perimeter of the hood.
>
>Thus, a 3'x3' hood, open on 4 sides will require about 1,200 cfm of air flow
>to effectively capture the fume. By locating the hood against a back wall, the
>open perimeter is reduced to 9', thus reducing the air flow requirements by
>300 cfm. If the sides are "half enclosed" by bring sheet metal out 1-1/2 feet
>from the back on each side, the open perimeter is reduced to 6', reducing air
>flow requirements to 600 cfm, but still giving good access.
>
>While 600 cfm is a small flow for a fan, it is a significant flow for a short
>chimney and low temperature air. Hopefully, the importance of making the hood
>as small and as enclosed as possible is well illustrated.
>
>Kindest regards,
>
>Kevin Chisholm
>
>Ronal W. Larson wrote:
>
>> In a "bounced" message, list member Elizabeth Bates of ITDG asked for help
>> in Kenya (Elsen Karstad please take note):
>>
>> Dear Stove network members
>>
>> This topic is not a 'follow on' of the previous discussions, but is
>> closely associated with the work being done on stoves. In this case,
>> we are hoping to install the best interventions that are currently
>> available, rather than looking to the future, so we would like to
>> know of stoves which are already 'up and running with some
>> success in situ.
>>
>> Intermediate Technology Development Group (ITDG) is at present working
>> on a project in Kenya looking at appropriate interventions for
>> alleviating household smoke in two communities, one in Kisumu, West
>> Kenya, and the other at Kajiado, some 100Km south of Nairobi. Most
>> homes in both communities use traditional three-stone fires.
>
>....del....
>
>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html
>For information about CHAMBERS STOVES
>http://www.ikweb.com/enuff/public_html/Chamber.htm

From elk at net2000ke.com Fri May 14 01:23:38 1999
From: elk at net2000ke.com (Elsen Karstad)
Date: Tue Aug 31 21:36:19 2004
Subject: Natural Draft Hoods
Message-ID: <199905140526.IAA04267@net2000ke.com>

We may be able to use the group to assemble a hypothetical hood and chimney.My initial contribution is to point out the value of the venturi effect. I've had some success in a factory situation- I increased flue draft considerably by curving the very top of the chimney over so the opening points down-wind.In a domestic situation (with or without a hood over the fire), this could be swiveled by hand to accommodated varying wind directions, or even regulated by a weather-vane arrangement if a smoothly operating pivot can be designed. Pointed INTO the wind, one could even envision a reverse flow providing fresh air ventilation in the absence of a cookfire.Does the interior size of the house matter? I imagine the size of the fire does (diameter), and the clearance required between the top of the pot & the hood to accommodate normal cooking practices. There will be a difference if the cook is sitting on a chair or squatting on the floor. Is there any consideration for the prevailing wind in house situation- e.g., rain blowing in the front door might be avoided by positioning the entrance in a down-wind direction. This could influence pressures in the house & the operation of any ventilation system.Elizabeth.... some more info? Maybe focus on the ferro-cement Maasai houses first. A Maasai that has changed any aspect of his/her traditional Manyatta dwelling would be a suitably open-minded candidate for this sort of trial.rgds;elk~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Elsen L. Karstad , P.O. Box 24371 Nairobi Kenyaelk@net2000ke.com tel/fax (+ 254 2) 884437

From mheat at mha-net.org Fri May 14 10:03:01 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:19 2004
Subject: Natural Draft Hoods
In-Reply-To: <199905140526.IAA04267@net2000ke.com>
Message-ID: <4.1.19990514085525.0099b380@mha-net.org>

At 08:25 AM 14/05/99 +0300, Elsen wrote:

We
may be able to use the group to assemble a hypothetical hood and
chimney.

My initial contribution is to point out the value of the venturi effect.
I've had some success in a factory situation- I increased flue draft
considerably by curving the very top of the chimney over so the opening
points down-wind.

In a domestic situation (with or without a hood over the fire), this
could be swiveled by hand to accommodated varying wind directions, or
even regulated by a weather-vane arrangement if a smoothly operating
pivot can be designed. Pointed INTO the wind, one could even envision a
reverse flow providing fresh air ventilation in the absence of a
cookfire.

A very interesting device is the Vacu-Stack chimney cap:
http://www.blackgoose.com/caps.htm

It uses simple airfoils without moving parts to reverse wind pressure and
translate downdrafts into updrafts - I've seen a demo at a trade show
that was quite convincing. The design appears relatively simple to
fabricate locally from sheet metal.

The inventor and American manufacturer is
Improved Consumer Products, Inc.
P.O. Box 1264
Attleboro Falls
MA 02763
(508)695-7000
FAX 695-4209

Best........Norbert

----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove
nospam)
Masonry Stove Builders
RR 5, Shawville-------
www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From john at gulland.ca Mon May 17 09:50:27 1999
From: john at gulland.ca (John Gulland)
Date: Tue Aug 31 21:36:19 2004
Subject: Natural Draft Hoods
In-Reply-To: <4.1.19990514085525.0099b380@mha-net.org>
Message-ID: <000301bea06c$41868680$03000004@uvlvr>

Elsen wrote:

In a domestic situation (with or without a hood over the fire), this could
be swiveled by hand to accommodated varying wind directions, or even
regulated by a weather-vane arrangement if a smoothly operating pivot can be
designed. Pointed INTO the wind, one could even envision a reverse flow
providing fresh air ventilation in the absence of a cookfire.

Then Norbert wrote:

A very interesting device is the Vacu-Stack chimney cap:
http://www.blackgoose.com/caps.htm

It uses simple airfoils without moving parts to reverse wind pressure and
translate downdrafts into updrafts - I've seen a demo at a trade show that
was quite convincing. The design appears relatively simple to fabricate
locally from sheet metal.
==================

J.G. The available research shows that even simple chimney cap designs tend
to induce draft in a chimney regardless of wind angle, provided the design
blocks the line-of-site access to the open top of the chimney. Canada
Mortgage and Housing Corporation has a report called "The Influence of
Termination Configuration on the Flow Performance of Flues". The
conclusions of this study seem to indicate that alternative designs, even
simple inexpensive ones, would have produced the same convincing result
Norbert saw demonstrated at the trade show.

Regarding the idea of a rotating termination that can be pointed away from
the wind to induce draft, such things might work well on an experimental
basis or for industrial use, but I have reservations about their
effectiveness for use by average people using cooking stoves. As a general
guide, I think it is best to avoid moving parts on chimneys.

Regards,
John

From larcon at sni.net Mon May 17 14:06:23 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:19 2004
Subject: Forwarding Liz Bates on Masai Houses
Message-ID: <v01540b00b365e9775a8e@[204.131.233.45]>

>From: "Liz Bates" <LizB@itdg.org.uk>
>To: owner-stoves-digest@crest.org (stoves-digest)
>Date: Mon, 17 May 1999 11:15:22 +0000
>MIME-Version: 1.0
>Subject: Re: stoves-digest V1 #706
>Priority: normal
>
>The Maasai community with whom we are working have, on the whole,
>adopted the ferrocement roofs, and are very open to new ideas......but
>they need to be cheap, and we need to be sure that we are not
>introducing something which will just prove to be a liability. The
>question of door draughts, I suspect, is not a major one because the
>houses are built such that one wall overlaps the other to form an
>entrance. A further wall means that you have to walk round a 'U' shape
>before you get into the house. Windows are very small....maybe
>2x2inches, or perhaps up to double that, but in thick mud walls. The
>'kitchen area is about 8x8ft, I think, but is very difficult to judge
>as the houses are almost completely dark. Ceiling height is about 6ft
>in an improved house. The two houses with experimental hoods are
>'hybrid' hoods + chimney. Three-stone fire on the floor, low 'hood'
>around it, going into a chimney flue at about 4ft above the ground.
>Does this help?
>Elizabeth Bates
>Email: elizabethb@itdg.org.uk
>Intermediate Technology
>Schumacher Centre for Technology and Development
>Bourton Hall
>Bourton-on-Dunsmore
>Warwickshire
>CV23 9QZ
>Tel:+44-1788 661100
>Fax:+44-1788 661101
>
>Url: http://www.oneworld.org/itdg
>Intl: http://www.itdg.org.pe
>Company Reg No 871954, England
>Charity No 247257
>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From uwo.invest at global.net.pg Thu May 20 11:41:33 1999
From: uwo.invest at global.net.pg (ATprojects)
Date: Tue Aug 31 21:36:19 2004
Subject: request for drum oven info
Message-ID: <199905201541.LAA26914@solstice.crest.org>

x-mac-creator="4D4F5353"
Content-Transfer-Encoding: 7bit
Sender: owner-stoves@crest.org
Precedence: bulk

Greetings from Papua New Guinea! I am a U.S. Peace Corps volunteer
working with a local NGO, ATprojects, located in Goroka, Eastern
Highlands Province. One of my current activities here is the
coordination of a village bakery development project. This address was
given to me by Stephen Karekezi, of the Foundation for Wood Stove
Dissemination (Kenya), as a potential resource for information regarding
drum ovens. Can you direct me toward any published information (print
or internet) on this topic? Thank you for your time and I look forward
to hearing from you in the near future.

Sincerely,

Skye O'Connor
Project Development Officer

____________________________________

ATprojects
Box 660
Goroka, Eastern Highlands Province
Papua New Guinea
phone: (675) 732 3278
fax: (675) 732 1458
uwo.invest@global.net.pg
www.global.net.pg/atprojects

From dstill at epud.org Thu May 20 12:56:56 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:19 2004
Subject: request for drum oven info
Message-ID: <001801bea2e3$6525bb00$4d0e66d1@default>

Dear Skye,

I am sending you today the Aprovecho booklet "Capturing Heat" which includes
an oven built from drums. Using steel drums it is possible to create a low
mass oven that uses much less wood than earthen ovens. The heat goes into
the bread, say ten to sixty pounds, not into the surrounding earth, maybe a
thousand pounds. Both earth and bread are the thermal load of the oven.
Getting rid of the earth greatly reduces fuel use. By forcing the heat to
rub against the drum that holds the bread, exit temperatures out of the
chimney are low. Most of the heat from a few sticks heats the 55 gallon
drum.

If you have any questions, that's what we're here for.

Dean Still
Aprovecho Research Center
apro@efn.org
-----Original Message-----
From: ATprojects <uwo.invest@global.net.pg>
To: stoves@crest.org <stoves@crest.org>
Date: Thursday, May 20, 1999 8:36 AM
Subject: request for drum oven info

>x-mac-creator="4D4F5353"
>Content-Transfer-Encoding: 7bit
>Sender: owner-stoves@crest.org
>Precedence: bulk
>
>Greetings from Papua New Guinea! I am a U.S. Peace Corps volunteer
>working with a local NGO, ATprojects, located in Goroka, Eastern
>Highlands Province. One of my current activities here is the
>coordination of a village bakery development project. This address was
>given to me by Stephen Karekezi, of the Foundation for Wood Stove
>Dissemination (Kenya), as a potential resource for information regarding
>drum ovens. Can you direct me toward any published information (print
>or internet) on this topic? Thank you for your time and I look forward
>to hearing from you in the near future.
>
>Sincerely,
>
>Skye O'Connor
>Project Development Officer
>
>____________________________________
>
>ATprojects
>Box 660
>Goroka, Eastern Highlands Province
>Papua New Guinea
>phone: (675) 732 3278
>fax: (675) 732 1458
>uwo.invest@global.net.pg
>www.global.net.pg/atprojects
>
>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html
>For information about CHAMBERS STOVES
>http://www.ikweb.com/enuff/public_html/Chamber.htm
>

From mheat at mha-net.org Thu May 20 20:57:30 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:19 2004
Subject: request for drum oven info
In-Reply-To: <001801bea2e3$6525bb00$4d0e66d1@default>
Message-ID: <4.1.19990520194750.00aa96d0@mha-net.org>

At 10:08 AM 20/05/99 -0700, Dean Still wrote:
>Dear Skye,
>
>I am sending you today the Aprovecho booklet "Capturing Heat" which includes
>an oven built from drums. (snip)

On the subject of ovens, a long awaited book on high efficiency retained
heat bakeovens has just been published by Chelsea Green Press. The authors
are Dan Wing and Alan Scott, and the book is titled "The Bread Builders". I
found it to be extremely well researched - there is a lot of scientific
information on authentic sourdough hearth breads, there's an excellent
section on refractories, and there are complete instructions for building
Alan's simple high-efficiency brick oven design, in use for many years now
in some of the best bakeries in North America, as well as backyard
versions. We've built several of these, and the owners are very happy with
them, both in domestic and commercial settings.

The book is available at Amazon.com, or through the MHA bookstore at
http://mha-net.org/html/bookstore.htm

Best.........Norbert
----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
Masonry Stove Builders
RR 5, Shawville------- www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From larcon at sni.net Fri May 21 00:01:45 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:19 2004
Subject: on steel vs brick ovens
Message-ID: <v01540b01b36a85fc6d1f@[204.131.233.25]>

1. Skye - can we sign you up as a list member? Let me know. Your mail
will go through faster.

2. Norbert - Thanks for the suggestion on the book. I will try to locate
and read. Maybe you can give us a little more on the stove details
discussed by these authors. Certainly there has been a long history of
brick ovens and there must be good reasons. Is energy efficiency one of
them? At what scale might these authors rethink using steel rather than
brick, do you think?

I have often wondered whether we could turn ovens into
charcoal-makers as well, so I hope the list can keep on the ovens topic a
bit longer. The energy storing capabilities of brick (or the lack of in
steel) are not as much of an issue if one is trying to see if
charcoal-making is feasible but we might as well try with the best
material.

As another aside - I have heard a number of people ask for
cook-stoves that could have some modification for an oven option. Anyone
want to describe any low cost oven conversion option they may have seen?

3. Dean - same questions for you, but with more of a thrust on the quality
of the bread coming out of the oven. (obviously most of us have stoves
made of steel - so there are obviously good reasons for steel as well.)
Any idea whether and where and when brick makes more sense than steel? Can
you give a little more detail on the Approvecho oven document? (Sizes,
costs, performance, etc.)

Stovers: Other thoughts on ovens?

(My apologies for not getting going very well yet on stoves -
several other projects still in line. Ron)

>At 10:08 AM 20/05/99 -0700, Dean Still wrote:
>>Dear Skye,
>>
>>I am sending you today the Aprovecho booklet "Capturing Heat" which includes
>>an oven built from drums. (snip)
>
>On the subject of ovens, a long awaited book on high efficiency retained
>heat bakeovens has just been published by Chelsea Green Press. The authors
>are Dan Wing and Alan Scott, and the book is titled "The Bread Builders". I
>found it to be extremely well researched - there is a lot of scientific
>information on authentic sourdough hearth breads, there's an excellent
>section on refractories, and there are complete instructions for building
>Alan's simple high-efficiency brick oven design, in use for many years now
>in some of the best bakeries in North America, as well as backyard
>versions. We've built several of these, and the owners are very happy with
>them, both in domestic and commercial settings.
>
>The book is available at Amazon.com, or through the MHA bookstore at
>http://mha-net.org/html/bookstore.htm
>
>Best.........Norbert
>----------------------------------------
>Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
>Masonry Stove Builders
>RR 5, Shawville------- www.mha-net.org/msb
>Quebec J0X 2Y0-------- fax:-----819.647.6082
>---------------------- voice:---819.647.5092
>
>
>
>
>
>Stoves List SPONSORS and ARCHIVES:
>http://solstice.crest.org/renewables/stoves-list-archive/
>Stoves Webpage
>http://www.ikweb.com/enuff/public_html/Stoves.html
>For information about CHAMBERS STOVES
>http://www.ikweb.com/enuff/public_html/Chamber.htm

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From dstill at epud.org Fri May 21 13:50:11 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:19 2004
Subject: on steel vs brick ovens
Message-ID: <001d01bea3b4$0c169580$c80e66d1@default>

Dear Ronal and Norbert,

More than ten years ago Alan Scott visited Aprovecho and built an early
version of his retained heat bread oven. People had a great time cooking in
it for a whole day after it was brought up to temperature. I remember all of
us getting stuffed with bread, cakes, pastry, etc. It was a wonderful time.

Over the years, we used both Alan's oven and a earthen oven for baking
bread. No one questioned the efficiency because we had nothing to compare it
to. Then Larry built a low mass bread oven right in between the two high
mass models. I tested Larry's Rocket oven one night before a visit from
thirty usually hungry Humbolt State students. We made 66 pounds of bread,
weighed after baking, and used 11 pounds of wood. The bread quality seemed
the same but we used spectacularly less fuel.

The Rocket cooking stove saves some fuel and women think it's ok when we
introduce it. But in Mexico when we first introduced the steel drum bread
oven, women actually cried because it saved so much hauling of firewood.
Earthen ovens are horribly inefficient!

After contemplation I believe that retained heat ovens mostly suffer from
two classic problems: not enough exposed internal surface area to lower exit
temperatures during the heating up period-inefficient heat transfer
initially. The little cave with a chimney on top is not convoluted like a
high mass heating stove. Too much of the heat just shoots up the chimney, in
this case. A better heat transfer necessitates more optimized surface area.

Then, high mass ovens mostly have insufficient insulation to keep the heat
doing work for as long as possible. Alan changed his design a few years ago
and added insulation, which helps a lot.

We would want perfect insulation around the mass if possible. That way the
captured heat would be put to best use. But the high temperature of the oven
surface pushes heat through insulation at an alarming rate! R40 seems good
in a house where the temperatures differences are low, but since the temp.
difference is so great in the case of an oven, insulation is less effective
so heat is more easily lost.

The spring class at Aprovecho designed a "best case" retained heat oven and
started building the prototype. It has 125 square feet of surface area where
heat rubs against the mass to lower exit temps. down to around 250F. It is
insulated to R 100 so that the heat isn't lost too quickly. After the summer
session finishes it, I'll report on efficiencies.

Now consider the low mass oven in comparison. It's easy to expose enough of
the steel drum to heat to lower exit temps. We split another drum
longitudinally and slide it over the first, leaving a 3/4" gap between the
two drums. The heat passes through this gap and rubs against the bottom,
sides and top of the inner barrel that contains the bread. The oven gets up
to 400 degrees about twenty minutes after starting the fire. The bread bakes
and the fire is extinguished.

I believe that this is an inherently more efficient approach. The temp.
curve, in the low mass oven, is almost straight up to the desired temp. and
then straight down. The curve in even a perfectly insulated high mass oven
wastes the heat at both ends of the curve when it's below the desired baking
temp.

We aren't trying to do a very difficult thing: get and hold heat in mass.
Larry is succeeding at doing a simple thing: put heat into bread.

I'm not sure if there is a difference in the quality of the bread. We have
great cooks at Aprovecho who make great tasting bread. Most bread is baked
in regular low mass ovens. I imagine that massive ovens are more of a luxury
item for commercial applications to even out temperature changes.

Best,

Dean

From mheat at mha-net.org Fri May 21 14:02:57 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:19 2004
Subject: on steel vs brick ovens
Message-ID: <4.1.19990521130058.00a46d10@mha-net.org>

At 10:03 PM 20/05/99 -0600, Ronal Larson wrote:

>2. Norbert - Thanks for the suggestion on the book. I will try to locate
>and read. Maybe you can give us a little more on the stove details
>discussed by these authors. Certainly there has been a long history of
>brick ovens and there must be good reasons. Is energy efficiency one of
>them? At what scale might these authors rethink using steel rather than
>brick, do you think?
(snip)

Hi Ron: These ovens are quite efficient if they are used regularly - every
2nd day, for example. If they are used occasionally, there is the penalty
for heating up the mass. In that case, some of the residual heat can be
used for drying food or firewood.

We've built an experimental electrically fired brick oven here at home that
we use for baking bread, among other things. It is described at
http://mha-net.org/msb/html/bakeov11.htm

Included is a 5 day temperature record. Once I got the insulation closed in
so that there were no convective losses, the temp drop from 490F to 316F,
for example, took 24.75 hrs. It is fired with a standard 3000W oven element
from the hardware store, and takes about 7 hrs to heat to 550 F from a cold
start (not included is about 1 hr soaking time required)

Dan and Alan's book gives the following efficiency figures, in terms of kg
of flour baked per kg of wood fuel:

theoretical maximum: 26 (unobtainable)
Alan Scott's retained heat oven design on reheat cycle: 15
Alan Scott's design on preheat cycle: 1.4
most efficient retained heat design found in developing world (Somalia): 1.1
unimproved Somalian retained heat oven: 0.33
externally fired steam tube oven in Somalia: 6.25

The main difference with modern retained heat oven designs is the use of
insulation.

> As another aside - I have heard a number of people ask for
>cook-stoves that could have some modification for an oven option. Anyone
>want to describe any low cost oven conversion option they may have seen?
>

On the old North American cookstoves, the flue gases were routed around a
sheet metal box. These ovens work (we have one), but are not known for
even-ness. There are several different oven designs for masonry heaters,
but you can also bake in the firebox after the fire is out.

According to the afficionados of authentic naturally fermented hearth
breads, it is impossible to reproduce the results of a brick oven by other
means. A lot of elements come into play, including moisture, fast bottom
heat from the hearth, etc.

Best..........Norbert
----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
Masonry Stove Builders
RR 5, Shawville------- www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From mheat at mha-net.org Fri May 21 14:07:10 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:19 2004
Subject: brick oven addendum
Message-ID: <4.1.19990521130141.00a3cbf0@mha-net.org>

At 10:03 PM 20/05/99 -0600, Ronal Larson wrote:

At what scale might these authors rethink using steel rather than
>brick, do you think?
(snip)

We recently built a brick oven with a 6' x 9' (2m x3m) hearth for a
commercial bakery near Ottawa. It is fired with about 150 kg of wood, and
produces about 800 0.7kg loaves per firing. ............ Norbert
----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
Masonry Stove Builders
RR 5, Shawville------- www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From mheat at mha-net.org Mon May 24 07:25:36 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:19 2004
Subject: Fwd: TRENDS in RENEWABLE ENERGIES, issue #81 for May 24
Message-ID: <4.1.19990524061115.009e0a50@mha-net.org>

A couple of interesting tidbits: ...Norbert

>Date: Sun, 23 May 1999 22:24:58 -0400
>From: Bill Eggertson <eggertson@renewables.ca>
>TRENDS in RENEWABLE ENERGIES
> issue #81 for May 24
>
>A 'heads up' overview of developments in renewable energy.
>Forward TRENDS to colleagues; subscription is free.
>Archives posted at http://www.renewables.ca.
>If contact information is not provided, it is not available.
>
>- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
>IN THIS ISSUE:
>
>Solar Heat Pumps are Cheapest in Most Applications
>Layoffs Start in California for U-S Wind Industry
>U-S Senate Backs Renewables
>Canada Rejects Call for Carbon Tax
>Green Supplier Registers Numerous Slogans
>California City Finalizes Deal for Green Energy
>Solar Technology Helps the Insurance Industry
>Renewable Options to Reduce Insurance Loss
>Association Set Up For Offshore Wind Power
>BP Amoco Hopes Market Shines on Solar Venture
>Is the Windmill Ready for a Comeback?
>Solar Firm Beats Setback; Finds Its Place in the Sun
>Research Group Says Conventional Energies are Fine
>Analysis of Japan's Energy
>Study of Electricity Industry to Examine Brand Niching
>DoE Releases Energy Analysis on Nations
>Nations Differ Over Greenhouse Gas Emissions
>Energy Tidbits
>
>- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
>
>Solar Heat Pumps are Cheapest in Most Applications
>A report prepared for Canada's energy department shows that
>earth energy units have the lowest lifecycle cost in 125 of 135
>new construction scenarios examined. Of the ten settings that
>were more expensive to install and operate than conventional
>heating options, eight were marginal. Payback periods
>ranged from immediate to as high as 40 years; the average
>was six years. Best applications are offices, arenas and high
>schools. Sales of earth energy units across Canada dropped
>in 1997 to a low of 2,000 units (residential and commercial),
>but manufacturers project sales growth to 2002 of 10-20% per
>year for commercial and 2-5% in the residential market. An
>earlier study showed that solar heat pumps have the lowest
>GHG emissions of any available technology.
>Details: http://www.earthenergy.ca

--- Hey, I guess fuelwood doesn't qualify as an "available technology"??..N

(snip)

>Canada Rejects Call for Carbon Tax
>One of the world's leading environmentalists says Canada
>must impose a tax on fossil fuels if the country wants to meet
>its Kyoto commitments for GHG reductions. Maurice Strong,
>now a special advisor to the United Nations, told an energy
>conference that a formerly-unthinkable carbon tax now is
>inevitable. Low oil prices must reflect real environmental
>costs, and a carbon tax is needed to develop renewable
>energies and encourage energy efficiency. Energy minister
>Ralph Goodale said Canada would not impose a carbon tax,
>and energy officials in Alberta say such a tax would increase
>the cost of fuel by 30 to 40 cents a litre. Amory Lovins was
>another speaker at the Ottawa conference.
>
(snip)

----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
Masonry Stove Builders
RR 5, Shawville------- www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From Reedtb2 at cs.com Mon May 24 08:48:51 1999
From: Reedtb2 at cs.com (Reedtb2@cs.com)
Date: Tue Aug 31 21:36:19 2004
Subject: on steel vs brick ovens
Message-ID: <7843aa87.247aa4b7@cs.com>

Dear Dean et al:

Good info - I'll order Alan's book. What a pleasure to be able to get
obscure books in ~ 3 days with 5 minutes on the web.

~~~~~~
I make all the bread in our house (mix in breadmaker, 2nd rising in pan, then
bake at 375F for about 25 minutes). d

It is my impression that very few people REALLY understand what goes on in an
oven. They set the oven to 350F and assume that that is the temperature of
whatever is inside. NOT SO!

I recently collected the following data with an oven thermometer and a meat
thermometer while cooking a loaf of bread.

TIME BREAD OVEN
TEMP-F TEMP-F
0 105 70
5 125 275
10 170 325
15 180 350
29 200 365
25 200 350
30 208 375

a) Please excuse degrees F - goes with the territory
b) I presume the initial 105 F is from heat of rising
c) I was surprised how long it took oven to reach its setpoint
d) I was not surprised that the inside of the bread never exceeded the
Denver boiling point of water (mile high)
e) Bread was delicious (normal)

The high heat of vaporization of water means that most items being cooked
will be at or below the local boiling point a short distance inside the
surface. The set temperature of the oven is primarily an indication of the
radiant energy transferrec to the bread, bread pan, turkey, potato etc. (And
it increases as the 4th power of absolute temperature.) And secondarily the
convective heat transfer from the air in the oven.

Does anyone know of a book on cooking that starts at this fundamental heat
transfer level?

~~~~~~
Another terra incognita in cooking is heat transfer in the microwave.
Depends in part on the surface and volume and placement of susceptor (item
being cooked, heat transfer to -OH type polar molecules), but not in a linear
fashion. Does anyone know of a scientific book on microwave cooking?

Good cooking and eating TOM REED BEF

In a message dated 5/21/99 11:54:18 AM Mountain Daylight Time,
dstill@epud.org writes:

<< Dear Ronal and Norbert,

More than ten years ago Alan Scott visited Aprovecho and built an early
version of his retained heat bread oven. People had a great time cooking in
it for a whole day after it was brought up to temperature. I remember all of
us getting stuffed with bread, cakes, pastry, etc. It was a wonderful time.

Over the years, we used both Alan's oven and a earthen oven for baking
bread. No one questioned the efficiency because we had nothing to compare it
to. Then Larry built a low mass bread oven right in between the two high
mass models. I tested Larry's Rocket oven one night before a visit from
thirty usually hungry Humbolt State students. We made 66 pounds of bread,
weighed after baking, and used 11 pounds of wood. The bread quality seemed
the same but we used spectacularly less fuel.

The Rocket cooking stove saves some fuel and women think it's ok when we
introduce it. But in Mexico when we first introduced the steel drum bread
oven, women actually cried because it saved so much hauling of firewood.
Earthen ovens are horribly inefficient!

After contemplation I believe that retained heat ovens mostly suffer from
two classic problems: not enough exposed internal surface area to lower exit
temperatures during the heating up period-inefficient heat transfer
initially. The little cave with a chimney on top is not convoluted like a
high mass heating stove. Too much of the heat just shoots up the chimney, in
this case. A better heat transfer necessitates more optimized surface area.

Then, high mass ovens mostly have insufficient insulation to keep the heat
doing work for as long as possible. Alan changed his design a few years ago
and added insulation, which helps a lot.

We would want perfect insulation around the mass if possible. That way the
captured heat would be put to best use. But the high temperature of the oven
surface pushes heat through insulation at an alarming rate! R40 seems good
in a house where the temperatures differences are low, but since the temp.
difference is so great in the case of an oven, insulation is less effective
so heat is more easily lost.

The spring class at Aprovecho designed a "best case" retained heat oven and
started building the prototype. It has 125 square feet of surface area where
heat rubs against the mass to lower exit temps. down to around 250F. It is
insulated to R 100 so that the heat isn't lost too quickly. After the summer
session finishes it, I'll report on efficiencies.

Now consider the low mass oven in comparison. It's easy to expose enough of
the steel drum to heat to lower exit temps. We split another drum
longitudinally and slide it over the first, leaving a 3/4" gap between the
two drums. The heat passes through this gap and rubs against the bottom,
sides and top of the inner barrel that contains the bread. The oven gets up
to 400 degrees about twenty minutes after starting the fire. The bread bakes
and the fire is extinguished.

I believe that this is an inherently more efficient approach. The temp.
curve, in the low mass oven, is almost straight up to the desired temp. and
then straight down. The curve in even a perfectly insulated high mass oven
wastes the heat at both ends of the curve when it's below the desired baking
temp.

We aren't trying to do a very difficult thing: get and hold heat in mass.
Larry is succeeding at doing a simple thing: put heat into bread.

I'm not sure if there is a difference in the quality of the bread. We have
great cooks at Aprovecho who make great tasting bread. Most bread is baked
in regular low mass ovens. I imagine that massive ovens are more of a luxury
item for commercial applications to even out temperature changes.

Best,

Dean

- >>
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

From larcon at sni.net Tue May 25 13:11:53 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:20 2004
Subject: Forwarding Bates on Masai house design
Message-ID: <v01540b00b37063214d8e@[204.131.233.26]>

Stovers: This follows earlier discussion pertinent to hood design.

>From: "Liz Bates" <LizB@itdg.org.uk>
>To: owner-stoves-digest@crest.org (stoves-digest)
>Date: Mon, 24 May 1999 17:07:22 +0000
>MIME-Version: 1.0
>Subject: Re: stoves-digest V1 #708
>Priority: normal
>
>
>I have contacted Stephen Gitonga, at IT Kenya, concerning some of the
>questions posed about more precise house information: these are his
>replies:
>Dimensions of Maasai house?
>
>It has no standard dimensions depending on the individual house
>
>Does the interior size of the house matter?
>
> Yes the interior of the house does matter. If the house is high,
> there is much room for air circulation and thus affecting the flow .
>Unimproved Masai houses are 5.2" . The improved ones have more room
>and are higher
>
>Does the size of the fire matter (diameter)? Yes, and also the
>clearance required between the top of the pot & the hood must
>accommodate normal cooking practices.
>
> The hood sometimes becomes a nuisance to the cook if the distance is
> not enough for movement. There will be a difference if the cook is
> sitting on a chair or squatting on the floor. The Masai cooks sit on
>low chairs when cooking and the hood becomes a nuisance when the cook
>wants to stand or carry on some other chores while standing.
>
>Is there any consideration for the prevailing wind in house situation-
>e.g., rain blowing in the front door? This might be avoided by
>positioning the entrance in a down-wind direction. This could
>influence pressures in the house & the operation of any ventilation
>system.
>
>The inside pressures of the house are highly influenced by the holes
>made on the walls of the house especially the one next to the
>fireplace the others on the roof and door itself. The effect is an
>environment where there are low circulation of air, resulting in
>deposition of particulates in the other rooms, especially the bedroom.
>There are, of course, distortions to this explanation as the
>positioning of the holes differs from one house to the other. One
>thing that is common is the positioning of the fireplace which is
>always away from the door and is thus protected from wind through the
>door.
>
>I hope this is helpful
>Thank you
>Liz Bates
>
>
>Elizabeth Bates
>Email: elizabethb@itdg.org.uk
>Intermediate Technology
>Schumacher Centre for Technology and Development
>Bourton Hall
>Bourton-on-Dunsmore
>Warwickshire
>CV23 9QZ
>Tel:+44-1788 661100
>Fax:+44-1788 661101
>
>Url: http://www.oneworld.org/itdg
>Intl: http://www.itdg.org.pe
>Company Reg No 871954, England
>Charity No 247257
>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From larcon at sni.net Tue May 25 13:17:29 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:20 2004
Subject: Forwarding Bates on Boiling Point 43
Message-ID: <v01540b01b37063ec7d21@[204.131.233.26]>

(Liz - could you please forward in the body of an e-mail the subject matter
that is referred to here. Quite a few members cannot receive attachments.)

Dear Stoves-network members

This letter is back in my usual capacity of Boiling Point editor. I
am now looking for potential authors for the next edition of Boiling
Point, which is on 'Fuel Options for Household Energy'. Attached is
a fairly comprehensive list of the possible topics which we discussed
at the recent BP editorial meeting. If you can think of anything
which we have not addressed, I would be pleased to know about it.The
information is attached as a WORD file.

If any members of the stoves network do not receive Boiling Point and
would like to do so, please feel welcome to contact me with
your full name and address to add to our database. Boiling Point is
distributed free of charge to about 1400 people worldwide. For those
who do not know it: 'Boiling Point is a technical journal for those
working with stoves and hosuehold energy. It deals with technical,
social, financial and environmental issues and aims to improve the
quality of life for poor communities living in the developing world.'

Thank you
Liz Bates

Elizabeth Bates
Email: elizabethb@itdg.org.uk
Intermediate Technology
Schumacher Centre for Technology and Development
Bourton Hall
Bourton-on-Dunsmore
Warwickshire
CV23 9QZ
Tel:+44-1788 661100
Fax:+44-1788 661101

Url: http://www.oneworld.org/itdg
Intl: http://www.itdg.org.pe
Company Reg No 871954, England
Charity No 247257

From larcon at sni.net Tue May 25 13:17:48 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:20 2004
Subject: Comparing Still and Neff on Ovens
Message-ID: <v01540b06b3707225d4ae@[204.131.233.26]>

Summary: Dean Still and Norbert Senf kindly responded last week to my
several questions on brick vs steel ovens. This note is only to offer my
conclusions after their responses. A few new questions below.

Conclusion #1 - Commercial large ovens are apt to remain as brick - due
mainly to perceived improved bread quality - perhaps especially to get
evenness of temperature.

Conclusion #2 - The brick ovens can operate at high efficiency - if used
regularly and with high R-value insulation. Norbert reports one FOM of 15
(wt bread baked/wt. wood) for one unit with reheat, but generally much
lower.

Conclusion #3 - For smaller units used irregularly, low mass (steel) units
should probably be considered - on grounds of improved efficiency. I
wonder if some small amount of brick would be justified to improve moisture
and heat transfer characteristics. High R-values are still strongly
justified. Dean reports one FOM of 6, with additional efficiency results
being promised

(Question #1 to Dean - Your 3/4 inch gap sounds like a major
advance to improve heat transfer to the inner steel drum. Have you tried
any tests with somewhat smaller gaps - as is suggested in Sam Baldwin's
thesis? ie- how optimized is this number?
Question #2 - You emphasized the losses due to a high exit
temperature, Have you studied whether there might there be some optimum
power profile, so that you start with a lower power level and therefore
lower exit temperatures?)

(Question #1 to Norbert - In your recent 6 sq meter brick oven -
with an FOM of 3.7 (800*0.7/150), how many times are loaves run through the
oven after firing the 150 kG of wood? What total time is required for this
firing?

Q#2 - You indicate a high FOM (of 6.25) for an "externally fired
steam tube oven in Somalia". Could you tell us more about this design and
when might it be a good choice for baking in other countries? What sort of
first costs?)

(To both and all - Obviously high R-value insulation is a key in
your responses. But high temperature insulation is relatively costly.
What have you found to be the least cost insulation approaches - and
especially for insualting materials apt to be found in developing
countries? What sort of R-value is possible for a one-year simple payback
time, assuming bread is baked daily in a size like Norbert's 800-loaf unit
)

Dean and Norbert - Thanks for some very enlightening discussion! I've
learned a lot.

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From mheat at mha-net.org Tue May 25 16:46:35 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:20 2004
Subject: Comparing Still and Neff on Ovens
In-Reply-To: <v01540b06b3707225d4ae@[204.131.233.26]>
Message-ID: <4.1.19990525141102.00a79400@mha-net.org>

At 11:19 AM 25/05/99 -0600, you wrote:
(snip)
(Question #1 to Norbert - In your recent 6 sq meter brick oven -
>with an FOM of 3.7 (800*0.7/150), how many times are loaves run through the
>oven after firing the 150 kG of wood? What total time is required for this
>firing?

Ronal: The loaves are in pans, and the oven holds about 100 loaves, so 8
batches are baked on a single firing. I believe that the oven is fired a
couple of times a week. At the tail end, some spelt break is baked, which
requires a lower temperature. There is some information on this oven at
http://mha-net.org/msb/html/bakeov08.htm

I believe that it takes about 3 - 4 hours to fire the oven, and that it
then soaks for a couple of hours. There are 3 2ft wide stainless steel
fold-down doors, so that the entire front of the oven opens for
loading/unloading. An insulation scheme for these doors would probably
reduce heat loss appreciably.

We also have an extensive Brick Oven Page at
http://mha-net.org/msb/html/bakeoven.htm

We have a copy there of some thermocouple data at various levels inside the
brickwork of several baking chambers, compiled by Dan Wing.

> Q#2 - You indicate a high FOM (of 6.25) for an "externally fired
>steam tube oven in Somalia". Could you tell us more about this design and
>when might it be a good choice for baking in other countries? What sort of
>first costs?)

I got this information from Dan Wing and Alan Scott's book, and they don't
provide any further details. You could contact Dan directly for more
details or a reference - there's an email link on our brick oven page. He
does describe the firing scheme in a standard commercial deck oven,
however, which consists of multiple refractory decks heated with steam
tubes. The tubes contain a small amount of water. When heat is applied at
one end, the superheated steam distributes the heat to the refractory decks.

We use "schedule 40" high pressure stainless tubing for hot water coils in
masonry heaters. It is rated at 16,000 psi. for 3/4" pipe. Thicker wall
pipe with ratings up to 44,000 psi is availabe.

> (To both and all - Obviously high R-value insulation is a key in
>your responses. But high temperature insulation is relatively costly.
>What have you found to be the least cost insulation approaches - and
>especially for insualting materials apt to be found in developing
>countries? What sort of R-value is possible for a one-year simple payback
>time, assuming bread is baked daily in a size like Norbert's 800-loaf unit
>)

We use either vermiculite or mineral wool. Here in Canada, we have "Roxul"
brand mineral wool batt insulation, also available in semi-rigid board
form. It is sold at building supply yards as a direct replacement for
fiberglass batts, and is very reasonably priced. At least 6 - 8" (R-20 -
R-30) is good on the sides, with 12" or more on top. In the test electric
oven that we built at home, we found surprisingly large convective losses
because of airflow through the insulating batts until everything was sealed
properly.

Insulating the hearth is more difficult. Alan Scott uses a 4" 6:1
portland:vermiculite concrete under the main hearth slab. We use 6" of Dow
Corning "Foamglass" at the bearing surfaces of the suspended slab. It is
foamed glass with a compressive strength of 100 psi. and costs $1.25 US per
sq. ft. per inch thickness. Thermal conductivity is 0.33 BTU-in/hr*sqft*F
(R=3 per inch), or 0.040 kcal/m*h*C at 0C, and 0.042 at 20C. The exposed
centre portion of the bottom of the slab is framed with a 6" horizontal
steel stud wall, filled with Roxul batts.

Alan's main structural innovation in brick oven construction is the use of
a reinforced refractory concrete cladding over the brick vault, thus
avoiding the use of traditional structural steel to restrain the vault's
side thrust. By using appropriate bond breaks, the whole assembly is able
to expand and contract with the thermal cycles.

Wood ash might be worth investigating as a low cost refractory insulation.

Best.........Norbert

----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
Masonry Stove Builders
RR 5, Shawville------- www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From dstill at epud.org Wed May 26 01:38:57 1999
From: dstill at epud.org (Dean Still)
Date: Tue Aug 31 21:36:20 2004
Subject: Fw: Comparing Still and Neff on Ovens
Message-ID: <001401bea73b$c2be19e0$640e66d1@default>

-----Original Message-----
From: Dean Still <dstill@epud.org>
To: Ronal W. Larson <larcon@sni.net>
Date: Tuesday, May 25, 1999 7:57 PM
Subject: Re: Comparing Still and Neff on Ovens

>Dear Ronal,
>
>Dr. Winiarski (Larry) suggests to fledgling stove designers here at
>Aprovecho that we keep the cross sectional area constant throughout the
>stove/oven so that draft is unimpeded. So, that's where we start.
>
>In a bread oven made from three steel drums we usually find that a 6 to 8
>inch diameter feed chamber is big enough. The same cross sectional area in
>an anulus surrounding a 55 gallon drum results in a very small gap.
>Basically, I think Larry would concur that the gap can be as small as
>possible as long as draft continues. We used 3/4" not because it's optimal
>but because we don't want the gap clogging up with residues.
>
>You're right, Ronal, the optimal gap, which is very small, results in an
>amazing jump in efficiency! Larry even tapers the gap under pots for best
>results. As the pot diameter widens the gap under the pot lessens to keep
>the same cross sectional area. Small differences under the griddle in the
>new Honduras plancha stove can change efficiencies as much as 10%!!!
>
>The right gap can be as little as 1/8". But, as mentioned, you have to
>balance this with maintainance problems. The 3/4" gap doesn't seem to clog.
>We ran one oven for 5 years and didn't have to clean it. So the compromise
>runs in this case to ease of operation rather than full on efficiency.
>
>
>INSULATION
>The third drum is split longitudinally as well and covers both inner
>barrels. A six inch gap is filled with natural insulation, usually wood
ash.
>We have also used dead coral. If aluminum foil is available leaving air
gaps
>between sheets of foil makes an incredibly good insulation. Larry's current
>work is to find A.T. methods to make insulating light weight fire brick on
>site. Anyone else know any work in this area?
>
>I'm sure that there is an optimal power rate. We try to design stoves/ovens
>to that the exit temperatures are in the 250 F range even at full power.
You
>do this by providing enough square footage of heat exchanger in the oven.
>Exit temps. drop when the thermal load (the bread, etc.) is put in the oven
>and from that point on the extra sticks burning are used mostly to
evaporate
>water. (1005 BTU per pound). A full oven is heated up by 4 or 5 one inch in
>diameter sticks burning. As the bread steams you will use 6 to 8 sticks and
>as the moisture is evaporated away go back down to 3 or 4 sticks until the
>bread is brown and done.
>
>We will report back to you with results on the high mass oven. But now I'm
>intrigued by trying to optimize the low mass, too. Maybe we'll assign
trying
>to get as close to a FOM of 26 to the summer interns and see what happens.
>We could move the fire much closer to the oven but every time I do it it's
>hard to get even temps. without adding (dare I say it!) mass.
>
>Best Regards,
>
>Dean
>
>-----Original Message-----
>From: Ronal W. Larson <larcon@sni.net>
>To: stoves@crest.org <stoves@crest.org>
>Date: Tuesday, May 25, 1999 10:10 AM
>Subject: Comparing Still and Neff on Ovens
>
>
>>Summary: Dean Still and Norbert Senf kindly responded last week to my
>>several questions on brick vs steel ovens. This note is only to offer my
>>conclusions after their responses. A few new questions below.
>>
>>Conclusion #1 - Commercial large ovens are apt to remain as brick - due
>>mainly to perceived improved bread quality - perhaps especially to get
>>evenness of temperature.
>>
>>Conclusion #2 - The brick ovens can operate at high efficiency - if used
>>regularly and with high R-value insulation. Norbert reports one FOM of 15
>>(wt bread baked/wt. wood) for one unit with reheat, but generally much
>>lower.
>>
>>Conclusion #3 - For smaller units used irregularly, low mass (steel) units
>>should probably be considered - on grounds of improved efficiency. I
>>wonder if some small amount of brick would be justified to improve
moisture
>>and heat transfer characteristics. High R-values are still strongly
>>justified. Dean reports one FOM of 6, with additional efficiency results
>>being promised
>>
>> (Question #1 to Dean - Your 3/4 inch gap sounds like a major
>>advance to improve heat transfer to the inner steel drum. Have you tried
>>any tests with somewhat smaller gaps - as is suggested in Sam Baldwin's
>>thesis? ie- how optimized is this number?
>> Question #2 - You emphasized the losses due to a high exit
>>temperature, Have you studied whether there might there be some optimum
>>power profile, so that you start with a lower power level and therefore
>>lower exit temperatures?)
>>
>>
>> (Question #1 to Norbert - In your recent 6 sq meter brick oven -
>>with an FOM of 3.7 (800*0.7/150), how many times are loaves run through
the
>>oven after firing the 150 kG of wood? What total time is required for
this
>>firing?
>>
>> Q#2 - You indicate a high FOM (of 6.25) for an "externally fired
>>steam tube oven in Somalia". Could you tell us more about this design and
>>when might it be a good choice for baking in other countries? What sort
of
>>first costs?)
>>
>> (To both and all - Obviously high R-value insulation is a key in
>>your responses. But high temperature insulation is relatively costly.
>>What have you found to be the least cost insulation approaches - and
>>especially for insualting materials apt to be found in developing
>>countries? What sort of R-value is possible for a one-year simple payback
>>time, assuming bread is baked daily in a size like Norbert's 800-loaf unit
>>)
>>
>>Dean and Norbert - Thanks for some very enlightening discussion! I've
>>learned a lot.
>>
>>Ron
>>
>>Ronal W. Larson, PhD
>>21547 Mountsfield Dr.
>>Golden, CO 80401, USA
>>303/526-9629; FAX same with warning
>>larcon@sni.net
>>
>>
>>Stoves List SPONSORS and ARCHIVES:
>>http://solstice.crest.org/renewables/stoves-list-archive/
>>Stoves Webpage
>>http://www.ikweb.com/enuff/public_html/Stoves.html
>>For information about CHAMBERS STOVES
>>http://www.ikweb.com/enuff/public_html/Chamber.htm
>>
>

From larcon at sni.net Wed May 26 09:35:12 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:20 2004
Subject: Forwarding Bates on BP special issue
Message-ID: <v01540b04b371a6acd401@[204.131.233.4]>

Stovers

>Please find details of topics which we hope to cover in Boiling Point
>43. I had not appreciated that 'attachments' were a problem
>Liz Bates
>

>Our next edition of Boiling Point will look at the topic 'Fuel
>Options for Household Energy'. At present I am looking for potential
>authors for this edition. ) The topics we hope to publish include:

>-Available fuel sources

> - Social, environmental, economic and technical benefits and
>constraints of individual fuels

>- Ways in which several fuels and technologies are used by individual
>households

>- What are the incentives and subsidies involved in access to fuel,
>and what is the effect on customer choice?

> - How do we influence those in power to make political decisions
>favourable to the poor?

>- What are the means to stimulate change?

> - Affordable options

>- What income-generating activities are there at household level
>which require particular fuel choices?

>- Alternative technologies, such as briquetting

> - Successful fuel substitution case studies

>- Health and environmental impacts of fuel substitution

> - What is the mechanism for replicating successful fuel substition
>projects?

> - Differences between urban and rural options for fuel selection and
>substitution
>

>The articles we seek are about 1500 words long, and we really need
>illustrations (either line drawings or photographs. The list above is
>intended to be helpful rather than limiting. If there is something on
>this topic which you feel should be addressed, please feel very
>welcome to submit a paper or papers to me either as typescript (or
>manuscript) or on disc (ideally WORD or ASCII) or by e-mail. We also
>have a 'non-theme' section, and I would welcome articles for this part
>of the journal as well.

> Thank you Liz Bates
>
>
>
>Elizabeth Bates
>Email: elizabethb@itdg.org.uk
>Intermediate Technology
>Schumacher Centre for Technology and Development
>Bourton Hall
>Bourton-on-Dunsmore
>Warwickshire
>CV23 9QZ
>Tel:+44-1788 661100
>Fax:+44-1788 661101
>
>Url: http://www.oneworld.org/itdg
>Intl: http://www.itdg.org.pe
>Company Reg No 871954, England
>Charity No 247257
>

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From mheat at mha-net.org Thu May 27 07:23:07 1999
From: mheat at mha-net.org (Norbert Senf)
Date: Tue Aug 31 21:36:20 2004
Subject: Oven design
In-Reply-To: <001401bea73b$c2be19e0$640e66d1@default>
Message-ID: <4.1.19990527045835.00a46ca0@mha-net.org>

At 10:50 PM 25/05/99 -0700, Dean Still wrote:
>
(snip)>> we keep the cross sectional area constant throughout the
>>stove/oven so that draft is unimpeded. So, that's where we start.
>>
>>In a bread oven made from three steel drums we usually find that a 6 to 8
>>inch diameter feed chamber is big enough. The same cross sectional area in
>>an anulus surrounding a 55 gallon drum results in a very small gap.
>>Basically, I think Larry would concur that the gap can be as small as
>>possible as long as draft continues. We used 3/4" not because it's optimal
>>but because we don't want the gap clogging up with residues.
>>
(snip)
>>I'm sure that there is an optimal power rate. We try to design stoves/ovens
>>to that the exit temperatures are in the 250 F range even at full power.
>You
>>do this by providing enough square footage of heat exchanger in the oven.

Hello Dean and Ronal:

There are a number of design rules for gas flows and heat exchange in
masonry heaters ... perhaps some of them are applicable to metal oven design:

- to get a good compromise between friction loss and heat exchange, the gas
speed should be just into the turbulent range, with a Reynold's number
around 3000.
Depending on gas temperature, this is roughly 0.5 m/s

- gas speed should be kept constant. Since the gases are cooling, the
overall cross sectional area of the channels is therefore reduced about 50%
between firebox exit and chimney entry. The firebox exit temp in a metal
oven would probably be less than in a masonry heater, so perhaps a 25%
reduction would be a starting point.

- in order to obtain an even outside surface temperature (to minimize
thermal stresses, in the case of masonry heaters), the wall section
thickness (mass) is reduced gradually. Since this can't be done with a
double wall sheet metal oven (other than by adding mass), perhaps another
approach would be to widen the channel section at the beginning to reduce
heat transfer and make it narrower at the end to increase heat transfer,
particularly with larger ovens. In other words, slower laminar flow where
gas temps are high and turbulent flow where temps are low.

- for heat transfer from a hot gas to a cool surface, downdrafting flows
are more efficient and predictable than updrafting flows. Turbulence sets
in at a lower Reynold's number. Gas mixing is ideal in downdrafting, and
tends to stratify in updrafting. (For heat transfer from a hot surface to a
cool gas, the reverse holds true).

Hope that some of that may be useful ----- Norbert

Best........Norbert
----------------------------------------
Norbert Senf---------- mheat@mha-net.org-nospam (remove nospam)
Masonry Stove Builders
RR 5, Shawville------- www.mha-net.org/msb
Quebec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092

From karve at wmi.co.in Fri May 28 00:33:43 1999
From: karve at wmi.co.in (karve)
Date: Tue Aug 31 21:36:20 2004
Subject: ARTI President visiting Germany
Message-ID: <374E1CDB.2197C2D6@wmi.co.in>

Dear Stovers,
This is to inform you that Dr. A.D. Karve, President, Appropriate
Rural Technology Institute (ARTI) will be visiting Germany for three
months from mid-November to mid-February. Alexander von Humboldt
foundation has invited him to present lectures on the innovative rural
technologies developed by ARTI, at German research organisations,
academic institutions, non-government German organisations working for
rural development in the third world, etc., of his choice.
If those of you who are in Germany are interested in having Dr.
Karve visit your organisation, please let me know at the earliest, so
that the plan of the lecture-tour can be prepared.
Please note that the trip is being funded by the Humboldt
Foundation, so you are expected just to offer local hospitality and no
other renumeration. Also please note that Dr. Karve is a doctorate from
Tuebingen University, and can communicate fluently in German.
If any of you can think of any German organisations who might be
interested in Dr. Karve's visit, please let me know, so that I can
contact them.
You may want to interact with Dr. Karve if you are interested in
Use of botany for rural development
Low cost techniques for increasing agricultural yields (proven under
Indian conditions)
Novel income-generating activities for rural women, small landholders,
etc.
Innovative approaches to domestication of non-timber forest product
species
Use of sea water for growing commercially useful plants
Modern techniques for running a rural-based nursery of seedlings of
commercial crops (this is also ideal as an occupational therapy for
alcoholics, drug addicts, etc., and as an income-generating activity for
mentally and physically challenged)
Use of bamboo in several outdoor structures like huts, green houses,
fencing, etc., that drastically reduces the cost of such structures
Low cost water storage for domestic and/or agricultural use
Improved stoves technology that is also user-friendly, and successful
strategies for popularising and commercialising such stoves in rural
populations
If you want more information regarding Dr. Karve or Appropriate
Rural Technology Institute, please contact Dr. Wolfgang Engelmann
(wolfgang.engelmann@uni-tuebingen.de), or Dr. Dierk Scheel
(dscheel@ipb.uni-halle.de). Dr. Scheel will be the host of Dr. Karve.
With regards,
Priyadarshini Karve

begin: vcard
fn: Dr. Priyadarshini Karve
n: ;Dr. Priyadarshini Karve
org: Appropriate Rural Technology Institue (ARTI)
adr: 2nd Floor, Maninee Apartments,;;Opposite Pure Foods Co., Dhayarigaon,;Pune,;Maharashtra;411 041;India
email;internet: karve@wmi.co.in
tel;work: 91 020 342217/4390348/4392284
tel;fax: -
tel;home: 91 020 233258
note: ARTI is an NGO committed to developing and standardising innovative approapriate rural technologies with special emphasis on making traditional rural enterprises more profitable and generating new employment opportnities through introduction of novel enterprises in rural areas.
x-mozilla-cpt: ;0
x-mozilla-html: FALSE
version: 2.1
end: vcard

From larcon at sni.net Sun May 30 01:42:54 1999
From: larcon at sni.net (Ronal W. Larson)
Date: Tue Aug 31 21:36:20 2004
Subject: further oven comments
Message-ID: <v01540b03b37680ca8c6e@[204.131.233.41]>

Thanks to Dean and Norbert for a fascinating exchange on stove
design. I don't think we reached closure on exactly when and where we
should expect metal or brick ovens should be used, but the exchange was a
good one.

Any more stove-design comments to throw in from anyone?

I leave tomorrow for a 10-14 day car trip to Berkeley (and an
expected chat with Kirk Smith). (Alex - I hope you can take over again for
awhile).

Ron

Ronal W. Larson, PhD
21547 Mountsfield Dr.
Golden, CO 80401, USA
303/526-9629; FAX same with warning
larcon@sni.net

From Alex.English at adan.kingston.net Sun May 30 22:38:11 1999
From: Alex.English at adan.kingston.net (*.english)
Date: Tue Aug 31 21:36:20 2004
Subject: (Fwd) Chimneys-L Mailing list.
Message-ID: <199905310238.WAA06453@adan.kingston.net>

Hello everyone,

I would like to take a moment to let everyone know about a similar
discussion list for the professionals of the hearth industry.

The list was created mainly for chimney sweeps but it has evolved into a
fantastic pool of information for anyone who is involved with the chimney
industry. The name of the list is CHIMNEYS-L it has been around for over 4
years and has over 335 industry related professionals from over 10 countries
participating. There are over 24 mb of archives available for viewing. If
you would like to subscribe visit the following web site:

http://www.netspace.org/cgi-bin/lwgate/CHIMNEYS-L/subscribe.html

Dave McKnew
List owner
http://chimneysweeps.com

------ =_NextPart_001_01BEAB07.BA902162
Content-Type: text/html
Content-Transfer-Encoding: quoted-printable

<TITLE>Chimney Sweeps Discussion List</TITLE>

Hello everyone,

I would like to take a = moment to let everyone know about a similar discussion list for the = professionals of the hearth industry.

The list was created = mainly for chimney sweeps but it has evolved into a fantastic pool of = information for anyone who is involved with the chimney industry. The = name of the list is CHIMNEYS-L it has been around for over 4 years and = has over 335 industry related professionals from over 10 countries = participating. There are over 24 mb of archives available for viewing. = If you would like to subscribe visit the following web site:

http://www.netspace.org/cgi-bin/lwgate/CHIMNEYS-L/subs= cribe.html

Dave McKnew
List owner
http://chimneysweeps.com

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Alex English
RR 2 Odessa, Ontario, Canada
K0H2H0 613-386-1927
Fax 613-386-1211
Stoves List SPONSORS and ARCHIVES:
http://solstice.crest.org/renewables/stoves-list-archive/
Stoves Webpage
http://www.ikweb.com/enuff/public_html/Stoves.html
For information about CHAMBERS STOVES
http://www.ikweb.com/enuff/public_html/Chamber.htm

BioEnergy Lists: Improved Biomass Cooking Stoves

May 1999 Biomass Cooking Stoves Archive