After measuring the pots used in the various comedores, I began looking around in the chatarreros (vendors of recycled stuff) to see what sizes of recycled barrels I could find that would be a good fit. One of the most commonly used pots is 40 cm in diameter, and I found a barrel that is 44 cm, almost a perfect fit after allowing a small space for the smoke to escape. I made a prototype and installed it in the comedor at Huaycan, the one that´s farthest away from where I live but where the people were the most enthusiastic about wanting my help. The stove has an opening at the bottom for feeding the wood, which leads into a brick-lined combustion chamber surrounded by insulation (in this case fiberglass wool, but ashes work fine, too). The pot is supported by a couple of steel rods which sit a few centimeters above the chamber. The hot air hits the bottom of the pot and then flows up along the sides of the pot before escaping from the barrel at the top. The combustion chamber gets very hot because of the insulation and the restricted entry of cold air, so there´s practically no irritating smoke emitted. At the right you can see how they have been cooking over an open fire, with a couple of bricks to support the pot. The new stove will use less than half as much wood as the old one, and it cost about $5 to make. Their current daily expense for wood (cooking three pots at a time) is $1.50, so the stove will pay for itself in just a few weeks.
The group who run the comedor also have a large (2 meter diameter) dome shaped bread oven that they had built to start a bakery. They´ve never gotten it to work well, and they want me to help them with that, too. Unfortunately the oven was built without a chimney, which is probably a large part of the reason that it´s difficult to heat up. We´ve pretty much ruled out modifying it, for fear of damaging it, so I´m going to take along a friend next time who has worked with such ovens for many years. Maybe he can find a way to make it usable.