[Stoves] Onil and Inkawasi Rocket Elbow Information Request

[Shannon M. Brink]

I am member of a student chapter of Engineers Without Borders.  We have
built two Inkawasi stoves with somewhat disappointing results.  (We are
still not achieving complete combustion, the sunken pot chambers are
problematic for accommodating a variety of cooking utensils, and the smoke
escapes from the gap around the pot skirts.)  The engineers on the team are
discouraged and have given up on the rocket elbow stove design.  Though I'm
not an engineer, I am skeptical that the stoves were built according to
specifications (one was tiny, the other huge); outside engineers who have
experience with similar stoves have suggested that our combustion chamber
(which was short‹only a little more than 12") was too short.

Our design objectives are threefold:
1) Reduce the amount of smoke
2) Reduce the amount of fuel wood necessary
3) Reduce the amount of time needed for cooking

We work in Peru, and the townspeople also use tusa (dried corn cobs) as a
fuel during certain seasons and to ignite the fire.  It produces a thick,
acrid smoke.

Sources outside the University have recommended that we look into other
rocket elbow stoves, such as the Onil stove.  I am interested in the
following data on the Onil stoves:
1) Materials list and costs
2) Results data (smoke reduction, percent complete combustion, fuel
consumption)
3) Plans (if available to the public)
4) Estimation of its effectiveness using the corn cob fuel
5) Any experience you have working with Helps International (I'm planning to
contact them directly as well)

The engineers in our group are currently working on chimneys instead of
stoves as a smoke-reduction technology.  Because this won't address the
combustion and efficiency issues, I am concerned about the viability of
simply installing chimneys over their existing stoves, which are two bricks
with rebar across the top.  Do you know something similar to a chimney has
been effective in other regions?

If you need further information about our project and testing it the
Inkawasi, I'm happy to share it.  I'm not familiar with how listserves work,
so tell me whether I can email that privately or what's the best way to get
it to you.

Thank you in advance, and best wishes.
SMB