The ambient concentration of airborne pollutants such as CO and PM2.5 particulates in rural homes of developing countries such as Kenya has been observed to exceed World Health Organization (WHO) exposure limits up to 30X, and US Environmental Protection Agency limits by 100X. This indoor air pollution (IAP) has been linked to nearly 3% of the global burden of disease and is a major contributor to as many as 2 million premature deaths each year. Advanced gasifier cookstoves clearly indicated their potential for reduced PM and CO emissions relative to three-stone fires but usability of gasifier stoves along with performance and cost have severely limited gasifier acceptance in the developing world. The list of limitations of semi-gasifier stoves include poor usability and user acceptance due to batch fed requirements, an inability to control cooking power output, and heavy startup and shut down transient emissions. Therefore, Envirofit believes that the critical barrier to obtaining a significant improvement in IAP from cooking practices is the combination of innovative stove design with high user acceptance. Due to this Envirofit is focusing its attention on the add-on forced air attachment designed for use on rocket elbow stoves to achieve target emissions reductions while maintaining high user acceptance and intuitive functionality. By achieving the proposed project goals, significant breakthroughs will be made to achieve greater than 85% emissions reduction with a side-feed stove that have a proven history of strong user acceptance. In addition, the technology developed will be deployable on numerous preexisting improved stove products in Kenya such as the Kuni Mbili and Upesi stoves which are already adopted in Kenya (which would not be possible with semi-gasifier technology). The ability of the technology to be deployed on numerous preexisting wood burning stoves provides a cost savings to the end user by removing the need to purchase an entirely new stove. It is expected that the technology will have a strong user acceptance since it is an addition to their current stove. It is anticipated that a forced air attachment has a strong potential to lead to a highly marketable product by leveraging Envirofit's proven expertise in improved cooking stove research and development. Envirofit has extensive knowledge in performing field trials and interfacing with potential customers, and has a mature manufacturing and supply chain system capable of successfully deploying the target product. By teaming with RTI International, successful execution of a thermoelectric generator as a power supply for the forced air attachment can be realized. Exploratory work in the area of forced air injection has already been completed with promising results and an obtained baseline knowledge that will aid in guiding the research path for the proposed stove enhancement technology.
Envirofit proposes the development of a forced air add on attachment for use with rocket style cookstoves. By increasing mixing within the combustion chamber this attachment will reduce PM2.5 and carbon monoxide emissions from the cookstove by more than 85% when compared with a three stone fire. By achieving these high levels of emission reductions this product can have a major impact on the respiratory health of women and children in Kenya and across the developing world.