Intro to stove building

There are primarily two different types of cook stoves that burn solid biomass in developing countries.  One is a normal cook stove where the firewood is completely contained inside the stove and all of it can burn, and air can enter the combustion chamber through various locations, including openings in the stove top and through the fire door if it is open.  The other type of cook stove is called a “rocket stove” where the firewood is inserted into an opening in the combustion chamber, and only the tip of the firewood burns and the air required for combustion enters the chamber from primarily below the burning firewood for best efficiency.  These are the two types of stove for the two stove projects I will be helping with in Xela.  Both are more efficient that the traditional cooking method of creating a “three-stone stove” (using three stones to support a pot over an open fire), and in addition to the improvements in efficiency, these two types of cook stoves can direct the smoke resulting from the fire to outside of the house, improving the health of the Guatemalan women and children who typically spend lots of time in the kitchen.

The cook stove with only the firebox is very easy to build (la estufa con solo la caja de fuego es muy facil para construir).  It costs only about $100 and can be build in a four mornings in four steps by student volunteers (la estufa cuesta solo mas o menos ochenta quetzales y es posible construir en cuatro mañanas en cuatro pasos con estudiantes voluntarios).  The materials and tools that are required for the stove are also very simple (Las materiales y las herrmientas es necesario para construer la estufa son muy simple).  The materials include cement blocks, bricks, white sand, cement mixture, mud, and sugar for the base and the firebox (las materiales necesario es blocks de cemento y ladrillos u sacos de arena blanca y sacos de barro molido, y tapas de panela).  Also needed is the stove top, the fire door and the chimney (la plancha y la puerta y la chimenea tambien es necesario).  The first step is to build the base which has three layers of bricks and cement blocks (el primero paso es contruir la base; hay tres hiladas de ladrillos y blocks de cemento en la base).  The second step is to lay out another three layers of bricks to build the firebox with holes for the door and the exhaust (en el segundo paso los estudiantes volantarios ponen tres hilados de ladrillos con dos hoyo, uno para la puerta y uno para la humo sala).  The third step involves building a ramp inside the firebox for the hot gasses to heat up the burner in the rear of the stove (el tercero paso es construer una rampa adentro la caja de fuego para la gases calientes ir a la humo sala).  The third step also involves installing the chimney and the cover to keep out rain (el tercero paso tambien necesita la instalación de la chiminea y la sombrero de la chininea).  In the fourth step, the firebox door is put in place (en el paso cuatro los estudiantes voluntarios poner la puerta).  In each step, the spaces between the bricks are filled with a mixture of mud, and after the each step, it is necessary to wait for the cement and mud mixtures to dry and this is why the stove cannot be finished in a single day (en cada paso necesario llenar las espacios con una mezcla de barro y despues de terminar cado  paso, es necesario esperar, y es la razón los estudiantes nececitan quatro dias para construer la estufa). 

I’m still learning about the “rocket stove.”  From what I currently know, in a rocket stove only the tip of the firewood is in the combustion chamber, allowing for more complete and cleaner burning which leads to the potential of a higher efficiency stove.  Furthermore, if the air enters below the coals, the combustion process is also expected to be better than in the enclosed firebox stove (si la aire entrar la caja de fuego abajo de la leña la proceso de combustion es mas eficiante de la estufa normal).  Commercial stoves with the rocket design can be 50 to 100% more expensive, but the trade off for the extra cost in the stove can be recovered by the savings in firewood costs.  In many engineering projects tradeoffs exist, and different stove designs may be better for different families (en muchos proyectos de ingenieria hay intercambios y deseños diferentes para las estufas pueden mas bien para familias diferentes).