A quantitative performance assessment of improved cooking stoves and traditional three-stone-fire stoves using a two-pot test design in Chamwino, Dodoma, Tanzania

In Tanzania, a majority of rural residents cook using firewood-based three-stone-fire stoves. In this study, quantitative performance differences between technologically advanced improved cooking stoves and three-stone-fire stoves are analysed. We test the performance of improved cooking stoves and three-stone-fire stoves using local cooks, foods, and fuels, in the semi-arid region of Dodoma in Tanzania. We used the cooking protocol of the Controlled Cooking Test following a two-pot test design. The findings of the study suggest that improved cooking stoves use less firewood and less time than three-stone-fire stoves to conduct a predefined cooking task. In total, 40 households were assessed and ask to complete two different cooking tasks: (1) a fast cooking meal (rice and vegetables) and (2) a slow cooking meal (beans and rice). For cooking task 1, the results show a significant reduction in firewood consumption of 37.1% by improved cooking stoves compared to traditional three-stone-fire stoves; for cooking task 2 a reduction of 15.6% is found. In addition, it was found that the time needed to conduct cooking tasks 1 and 2 was significantly reduced by 26.8% and 22.8% respectively, when improved cooking stoves were used instead of three-stone-fire-stoves. We observed that the villagers altered the initial improved cooking stove design, resulting in the so-called modified improved cooking stove. In an additional Controlled Cooking Test, we conducted cooking task 3: a very fast cooking meal (maize flour and vegetables) within 32 households. Significant changes between the initial and modified improved cooking stoves regarding firewood and time consumption were not detected. However, analyses show that both firewood and time consumption during cooking was reduced when large amounts (for 6–7 household members) of food were prepared instead of small amounts (for 2–3 household members)