The Field Informs the Lab In Part 1, we gave examples of how field studies can provide unpleasantly surprising results. Rocket stoves were designed to make a little less smoke and use substantially less fuel. So when the rocket stove was field tested by USAID the inventor, Dr. Larry Winiarski, was not surprised that the […]
ARC has been unpleasantly surprised on several occasions by the results of USAID field studies. For example: When a popular high mass Rocket stove (6-brick stove) used about as much wood to cook compared to open fires. In fact, the open fire outperformed or equaled the performance of all the high mass stoves! When even […]
The air in a kitchen has to be very clean to protect women and children from multiple diseases. Unfortunately, moderate amounts of smoke seem to damage health almost as much as higher concentrations. As exposure rises from zero, the chance that a child will get pneumonia increases sharply and then levels off so that indoor […]
In 2018, the World Health Organization concluded, “Every day around the world, billions of children are exposed to unsafe levels of air pollution. The result is a global public health emergency.” The WHO recommends that a combination of actions may be most effective. Aprovecho has used Retained Heat Cookers (Hayboxes) for decades and we recommend […]
When Dean Still came to Aprovecho in 1989, Dr. Larry Winiarski asked him to compare the thermal efficiency of the Lorena stove and the Three Stone Fire. The testing revealed a problem for the ARC staff when our Lorena used three times more fuel than a carefully operated open fire! Half of the staff, who […]
Smaller fires are often cleaner burning compared to larger fires, and higher heat transfer efficiencies allow the use of smaller fires while the time to boil stays acceptable. A pot skirt which creates a narrow channel gap reduces fuel use and time to boil. Dr. Sam Baldwin recommended 10mm to 11mm channel gaps for household cook […]
As with any tool, the skill of the operator determines how well the work is accomplished. It takes years to learn how to use a hammer or shovel. The Three Stone Fire can be effective and clean or it can be very dirty and wasteful. In some kitchens, large fires use a lot of wood […]
The ARC/EPA 2011 book “Test Results of Cook Stove Performance” compares performance and emissions, including turn down ratio and firepower, from survey of 18 stoves. Firepower is a measure of how much energy is released per unit of time. More energy is required to quickly boil water. Less energy is needed to simmer food. The […]
The Chitetezo Mbaula cookstove is distributed by United Purpose in Malawi with the goal of combating deforestation by replacing the traditional charcoal/firewood cooking stoves. In an effort to assist, ARC worked with stakeholders to see how small changes in the stove might translate into fuel and emissions reductions in lab tests. Of course, this information […]
Several articles have pointed out that using biomass-heating stoves can result in health problems in densely populated areas. We are working with friends at the EPA to think about how we might define PM2.5 emission rates for residential biomass heating stoves that would protect health in densely populated cities. When the population density goes up (more […]