1. RESEARCH POSTER PRESENTATION DESIGN © 2012
www.PosterPresentations.com
Badly designed wood-burning cook stoves:
-Waste extra time to heat up even before cooking
-Lose heat easily while cooking due to poor insulation
-Produce excessive amounts of smoke
As a consequence, the stoves:
-Waste wood for fuel to maintain heat
-Waste time and money to buy or collect fuel
-Encourage deforestation to meet unnecessary demand
-Negatively affect health every day by polluting the air
Why Worry About Stoves?
-Wood is first burned in the combustion chamber
-Heat rises to the first pot, insulated by ash. Since it is directly over the
pot, the pot can reach a boil
-Heat passes to a second chamber through a small gap in the dividing
wall
-With the second chamber, the heat and smoke stay in the stove for more
time so the particulates in the smoke continue to burn
-Cleaner smoke, with less irritating particles, exits chimney
Inside of the Model
After reading some documents that mentioned adobe bricks off-handedly, I
realized that could be a clue to more information. Though we did not make
our bricks ourselves, they were similar to adobe, so using an adobe-style
mortar between bricks would most likely bond well. Furthermore, the
subject is well-developed out of more wide-spread interest, with details on
the theory as well as the application.
Breakthrough
Results
While following leads and understanding how adobe could be applied to
stoves, I stumbled upon useful tips in constructing the stove, but more
important was the background around the tidbits. More than just a list of
facts, they also explained the overall principles that could be generalized to
different locations. For instance:
-Understanding the best proportions of clay to use, since too little would
not bind bricks together but too much would weaken the joins. In practice,
soil composition changes for each location so a simple shake test can
evaluate whether the soil would be appropriate to use.
-Comparing the effects of adding several other materials to the soil. While
the original manual called for finely chopped grass, it is not the only
option. Though grass acts as a direct link within the drying mixture, it can
be supplemented or replaced with sand for greater strength.
-Most practically, the best conditions for preparing adobe. A likely
explanation of why the first attempt cracked was that the still-drying
mortar shrank too much as water evaporated so they could not stick to the
bricks. Soaking the bricks also before spreading the mix over it slows rate
of evaporation and shrinkage.
References
Though details are not referenced in the poster directly, resources
mentioned are below:
- “Testing Soil for Clay Content” is a video hosted on Youtube that
demonstrates qualitative measurements of clay along with a shake test
- Vargas, J. and et al, “Seismic strength of adobe masonry,” 1986,
Materials and Structures 19, 253-258. It compares types of adobe
reinforcement, including graphs measuring cracks and strength under
stress.
- Hohn, Charles M., “ABCs of Making Adobe Bricks,” 2011, New
Mexico State University. http://aces.nmsu.edu/pubs/_g/g-
521/welcome.html
Acknowledgements
Thanks to Cal Energy Corps and blueEnergy for this opportunity, and the
Peace Corps for support
Thanks also to people with blueEnergy who helped move the project past
obstacles and answered questions:
Christopher Sparadeo, Gilles Charlier, Eric Lopp, Casey Callais
Talia Macauley, Holly McKenna, Dylan Dibble
And Don Melvin and his family for their help
However, an improved cook stove will reduce emissions, save fuel, and
still remain easy to use so the new technology will be more easily
accepted. Even if the stove is a miracle, if it is too intimidating or
unfamiliar it may not become popular.
University of California, Berkeley; with blueEnergy
Emily Chou
Testing Efficient Cooking Stoves for a Healthier Lifestyle
Despite the openings
between walls and
roof, there was still
enough lingering
smoke to cure their
meat-- but also
irritate lungs.
This stove, little more than an
open box, was used inside of the
house
Milestones
I worked with blueEnergy, a renewable energy NGO in Bluefields,
Nicaragua, on improving cook stoves for families in isolated communities.
We studied the Inkawasi model, which was designed by Peace Corps
volunteers in other Latin American countries. It seemed promising, but
-The model had not been tested specifically on the Caribbean coast
-Instruction manual was vague and imprecise
Plan of Action:
Evaluate its user-friendliness
Gain experience with the model by:
-brainstorming possible areas of improvement
-building a stove
Develop clearer instructions with our discoveries
We started construction on a stove at blueEnergy, but were frustrated by
the persistent cracks when the exterior mud-and-grass coat dried. While
our manual had given proportions for the mix, they were very general
descriptions dependent on individual cases, such as “a bucket’s worth.”
Introduction
Even before the final polish
was added, it was clear the
mixture used here was much
easier to work with.
A side-view diagram, with the
wall cutaway.
Patching cracks with more
worked temporarily, but
when that second layer
dried, it often cracked
again. The unexpected
problem demonstrated a
renewed need for precision
to prevent confusion.
When we came back to the first project, we knew that the stove could look
much better so we dismantled the stove, preparing to rebuilt it.
However, the mixture’s success had been partly luck, so we had to find
more information to know what to do differently. Literature on one
specific stove model out of the many types in existence is limited though,
so I thought I faced a dead end.
We had nearly completed it before we went to Rocky Point to build a
stove. The Rocky Point stove, with Don Melvin’s help, was much less
problematic, but with only a little more understanding of the differences.
Don Melvin, preparing for our arrival, had already helpfully mixed the
mud for us, but his proportions were no more exact than ours.
As we were planning the stove, a Peace Corp volunteer invited us to see
an installation of the stove, the first one they would build on the Caribbean
coast. A volunteer who specialized in building stoves visited for a few days
to direct the community.
It was very reassuring to see the process before trying it ourselves.
When the thickness of
the clay layer after
settling is compared to
the sample layer, the
proportion is found