[Stoves] NY Times article on what fuel poor need.

Thu Dec 5 15:32:57 CST 2013

Hi Ron

See replies below

Roger:  

   Very nice job on reporting the evolution of the No-Flay.  I see some very clever design features there - and a very nice cost ($10).  I look forward to hearing of your upcoming more detailed test results.

 Some nit picking questions:

   1.  You are recommending a 1.5 cm gap from outer unfired wall to pot.  I think Dean Still would recommend maybe half that.  Any specific reason for 1.5 cm?

We found 1.5 cm worked nicely with the typical 34 cm (14”) large pots (cooking for 14 in the household on average). The gap has to be sized to the combustion air flow you require. A bigger heat demand requires a bigger gap. Also from a practical standpoint a 1.5 cm was a gap the masons could work with, a smaller gap would cause installation issues. 

2.       How do you support the pot above the three fired brick stack?  Spacing also 1.5 cm?  Or more?

Yes we just cut the aluminum pot legs with a hacksaw to leave about a 1.5-2cm stub on the legs

3.       What are the range of pot diameters you can accommodate?  Has any family bought 2 for different pot sizes for types of food?

Our experience to date is the stove can accommodate pots from about 30 cm -60cm but we haven’t gone bigger yet.  In Senegal and Gambia most users want a 5 brick layer high stove for rice and millet cooking and a 4 brick layer high sauce pan stove. At McGill University a student is working to develop a bigger prototype for parboiling rice. 

     4.  I can understand the recommendation for outside cooking, but also see the no-flay as working indoors for some cultures.  One objection I had once was taking up space.  Any use of your no-flays indoors?   The outdoor use any problem with rainfall on the unfired bricks?

We started installing indoors and it was the communities that decided to build the stove outdoors once they realized they could cook outdoors under windy conditions with the double wall design. They never could do that before safely or efficiently with a 3 stone fire.  To protect from rain most just put up a slanted sheet of tin and two wooden supports against an existing kitchen wall.  

      5.  I am unaware of any other stove with internal support using the fired bricks.  Nice concept.  I like there are three, not four inside.  The 20 cm height for three could be varied a little for different size pots and flames?  The fired bricks seem to cost 10 cents each, and the unfired at a little less than half that.  Could the fired bricks be supplied in rounded arc shapes similarly?  (Trying to move towards a TLUD version of same - needing a total enclosure.)

We use 4 centre bricks on the bigger stoves in a diamond like pattern to support bigger pots. The 20 cm height is really a function of the brick thickness to save on materials. We could go higher, but it’s also the height they are used to cooking at so very user friendly. We went with smooth sided bricks because they are easier to pack and less breakage in transport. 

      6.  A TLUD all-clay, local construction version (to obtain char) seems doable - but would need drop down (removable) metal fuel containers.  I hope some reader can report they tried it.  Maybe later I will.  Getting rid of metal is great.  I think with wider fired bricks you might not need any outer layer, although that does provide some nice preheating.

Paul Anderson and I discussed this as a hybrid stove concept in Seattle, you use the TLUD insert and place it inside the fired bricks when you have the TLUD fuel and remove it and cook with wood when you don’t. 

     7.  Is it necessary to sell this at $5?  I would think your fuel savings could easily justify the full $10 cost.

Well it’s a new stove and this area is very poor in west africa. So if you can’t install stoves unless you discount it to launch it, you have to subsidize. Hopefully they will build it themselves locally and become wealthy enough to be able to afford to buy it without subsidy in the future. 

     8.  Your cost pie-chart showed a “micro” transport cost.  What is that?

That’s brick redistribution costs in the community. So we bring bricks by truck or tractor wagon to a community but you have to donkey cart it to each individual household so that’s our “micro” transport cost. 

Again thanks for reporting on some very nice approaches.  Best of luck on future sales.

THANKS! 
Ron

From: Ronal W. Larson <rongretlarson at comcast.net>
To: Roger Samson <rogerenroute at yahoo.ca>; Discussion of biomass <stoves at lists.bioenergylists.org> 
Sent: Thursday, December 5, 2013 3:10:24 PM
Subject: Re: [Stoves] NY Times article on what fuel poor need.

Roger:  