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

ResultsWhile 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.

ReferencesThough 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 buckets 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 mixtures 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 Melvins 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