Powered by the Problem: A TEG-Powered Smoke Exhaust System for Off-Grid Communities

I was born in India, and not in one of the more fortunate parts. My parents worked relentlessly to change that, and when I was seven, we moved to Canada. Despite this, we return to India every year to stay connected to our roots. I’ve always valued these visits, but over time, I began to notice something I could no longer ignore. All around me were life-threatening problems that seemed preventable.

One stood out most: smoke inhalation. Many families without access to clean stoves or ventilation rely on open fires to cook, often indoors. As a result, they are exposed to dangerous levels of smoke daily, contributing to over 2.1 million deaths each year.

This led me to ask: how can we reduce indoor air pollution in low income communities without relying on expensive or electricity-dependent solutions? My project focuses on designing a practical, affordable, and accessible ventilation system that works with existing cooking methods.

This solution is intended for low-income and rural households, particularly women and children who face the highest exposure. By reducing harmful smoke inhalation, it aims to lower respiratory illness, prevent avoidable deaths, and improve overall quality of life.

Ultimately, my goal is to create a solution that bridges the gap between innovation and accessibility because where someone lives should not determine whether they can breathe safely.

From interviewing relatives living in off-grid communities in India, I found out that most solutions fail because they need grid electricity, expensive fuel, or permanent installation. This shaped my design requirements: zero grid, zero fuel cost, and zero installation.

Two fundamental scientific principles guided system development. First, the Seebeck effect enables direct conversion of waste heat from the cooking fire into electrical potential. Second, the Venturi effect governs the relationship between cross sectional area reduction and pressure drop, which was exploited to optimize smoke capture. Four distinct hood geometries were designed in CAD, fabricated from PETG filament, and empirically evaluated at constant fan power. The hoods were evaluated by airflow, laminar flow attachment, flow separation, and turbulence levels.

The thermoelectric generators are configured in a planar array and sandwiched between two aluminum plates(Initial prototyping utilized a repurposed fan stand that was later discarded for simplicity as shown in image 2). A finned aluminum heat sink was mounted on the cold side of the plate to enhance convective heat dissipation, maximizing the temperature gradient across the TEGs. Wago 221 lever connectors were employed for all electrical splices, enabling tool free, reusable, low resistance connections. The fan was mounted inside a 10 inch duct fan housing. Four hood shapes were tested. The final hood was made from a steel HVAC reducer for heat resistance.

The complete system was tested for PM2.5 reduction using a PM2.5 sensor placed 45 cm from the smoke source. Baseline concentration measurements were recorded for 5 minutes with the system deactivated, followed by 5 minute intervention measurements with the system activated. The test sequence was replicated five times to ensure statistical reliability.

Empirical testing was conducted on four different hood geometries to optimize smoke capture efficiency. The convergent S curve hood outperformed all other designs, achieving 95 CFM airflow with only 5 Pa pressure drop. This represents a 46% improvement in airflow and a 72% reduction in pressure drop compared to the convergent divergent hourglass design.

Thermoelectric characterization confirmed that a two TEGs generate 2.78 watts at 100°C temperature difference and 6.92 watts at 150°C difference. The Seebeck coefficient was measured at 0.058 V per degree Celsius with an R squared value of 0.998, confirming the linear relationship between voltage and temperature gradient.

The system reduced PM2.5 concentration from 820 to 328 micrograms per cubic meter, a 60% reduction.

Fan blade optimization testing compared 2, 3, 4, and 5 blade configurations. The 5 blade steel fan with 25 degree pitch achieved 95 CFM airflow at 7.5 watts, providing the best balance of airflow and power draw within the TEG output range. Fewer blades moved less air.

The complete system was assembled and tested for continuous operation. The fan ran consistently when the TEGs hot sides reached approximately 100°C. At typical cooking temperatures between 125 and 150°C, the fan achieved 3000 to 4200 RPM, producing sufficient suction to capture 95% of smoke.

All three hypotheses were confirmed. The TEGs generated sufficient power to run the DC fan. The S curve hood achieved 95% capture efficiency, exceeding the 15% improvement target. The system reduced PM2.5 by 60%, surpassing the 50% target.

The system requires no grid electricity, no fuel purchases, and no permanent installation. It runs entirely on waste heat from the cooking fire. Total material cost was under $50.

The conclusions drawn from this project demonstrate that waste heat from a cooking fire can power effective smoke removal. The system achieved three key outcomes: it generated sufficient electricity from two TEGs, captured 95% of smoke using an optimized S curve hood, and reduced breathing zone PM2.5 by 60%.

The most important finding is that the fire which creates the smoke can also power its removal. No new energy source was added. The energy was already there. Families do not need to change how they cook. They use the same fire, same pots, same fuel. The system sits beside the fire and starts working automatically when it gets hot.

The components are not special. Someone in a rural village could build this system from locally available parts.

The biggest barrier to clean cooking is not upfront cost. It is ongoing fuel cost. LPG stoves need refills every few weeks. Solar fans need new batteries every two years. This system has zero recurring cost. Once built, it runs for free on waste heat. A family earning $800 per year can afford it.

A 60% reduction in PM2.5 from 820 to 328 μg/m³ would lower childhood pneumonia risk by approximately 27% and reduce cardiovascular mortality by an estimated 19%. Deployed at scale, this could save hundreds of thousands of lives annually. Now it must reach the people who need it most.

India Partnership: I will partner with the Kashi Annapurna Annakshetra Trust to field test 10-20 prototypes in real households, monitoring user acceptance and PM2.5 reduction.

Battery Integration: Adding a 12V deep cycle battery with a charge controller would store energy when the fire is hot and power the fan continuously even when the fire cools, enabling 24/7 smoke removal.

Scalability (More TEGs): Wiring additional TEGs in series would increase total voltage and power output; four TEGs could produce 11 to 28 watts, driving higher fan speeds and greater airflow for larger kitchens or multiple cooking stations.

Peel Regional Science Fair for recognizing this system and allowing me to compete at CWSF!

My parents for their support and for taking me to India every year, where I first saw the problem this project addresses.

My relatives in rural India for sharing their experiences and teaching me what families actually need.

The Kashi Annapurna Annakshetra Trust for their partnership and guidance.

The Canada Wide Science Fair judges for their time and feedback!

World Health Organization. (2023). Household air pollution and health. https://www.who.int/news-room/fact-sheets/detail/household-air-pollution-and-health

Global Burden of Disease Collaborative Network. (2021). Global burden of disease study 2021. Institute for Health Metrics and Evaluation.

Lancet Respiratory Medicine. (2022). Household air pollution and child health. The Lancet Respiratory Medicine, 10(1), 1-2.

Gordon, S. B., Bruce, N. G., Grigg, J., Hibberd, P. L., Kurmi, O. P., Lam, K. B., ... & Mehta, S. (2014). Respiratory risks from household air pollution in low and middle income countries. The Lancet Respiratory Medicine, 2(10), 823-860.

Cohen, A. J., Brauer, M., Burnett, R., Anderson, H. R., Frostad, J., Estep, K., ... & Forouzanfar, M. H. (2017). Estimates and 25-year trends of the global burden of disease attributable to ambient air pollution. The Lancet, 389(10082), 1907-1918.

Yang, Y., et al. (2026). Short-term PM2.5 exposure and cardiovascular mortality: A global exposure-response analysis. Journal of the American College of Cardiology, 87(3), 245-260.

Liu, C., Chen, R., Sera, F., Vicedo-Cabrera, A. M., Guo, Y., Tong, S., ... & Kan, H. (2019). Ambient particulate air pollution and daily mortality in 652 cities. New England Journal of Medicine, 381(8), 705-715.

Kelly, F. J., & Fussell, J. C. (2015). Air pollution and public health: Emerging hazards and improved understanding of risk. Environmental Geochemistry and Health, 37(4), 631-649.

Brook, R. D., Rajagopalan, S., Pope, C. A., Brook, J. R., Bhatnagar, A., Diez-Roux, A. V., ... & Kaufman, J. D. (2010). Particulate matter air pollution and cardiovascular disease. Circulation, 121(21), 2331-2378.

International Agency for Research on Cancer. (2012). IARC monographs on the evaluation of carcinogenic risks to humans: Volume 109. Outdoor air pollution. IARC.

Naota, M., et al. (2009). Caveolae-mediated transport of nanoparticles across the alveolar-capillary barrier. Inhalation Toxicology, 21(S1), 54-60.

Liu, X., et al. (2024). Translocation of inhaled particulate matter to red blood cells in humans. Environmental Health Perspectives, 132(2), 027005.

International Commission on Radiological Protection. (1994). Human respiratory tract model for radiological protection. ICRP Publication 66.

Environmental Health Perspectives. (2004). Long-term retention of particles in the human lung. Environmental Health Perspectives, 112(3), 321-327.

Bond, T. C., Doherty, S. J., Fahey, D. W., Forster, P. M., Berntsen, T., DeAngelo, B. J., ... & Zender, C. S. (2013). Bounding the role of black carbon in the climate system. Journal of Geophysical Research: Atmospheres, 118(11), 5380-5552.

World Bank. (2022). Energy access report 2022. World Bank Group.

Batchelor, S., Brown, E., Scott, N., & Leary, J. (2019). Solar powered ventilation for clean cooking: Challenges and opportunities. Development Engineering, 4, 100042.

Pope, D., Bruce, N., Dherani, M., Jagoe, K., & Moghaddam, P. (2021). Real-life effectiveness of improved biomass stoves in reducing household air pollution in rural Malawi. Environmental Health Perspectives, 129(4), 047001.

Smith-Sivertsen, T., Díaz, E., Pope, D., Lie, R. T., Díaz, A., McCracken, J., ... & Bruce, N. (2009). Effect of reducing indoor air pollution on women's respiratory symptoms: The RESPIRE randomized trial, Guatemala. BMJ, 338, b481.

Mobarak, A. M., Dwivedi, P., Bailis, R., Hildemann, L., & Miller, G. (2012). Low demand for nontraditional cookstove technologies. Proceedings of the National Academy of Sciences, 109(27), 10815-10820.

UN Habitat. (2021). Housing and living conditions in low-income countries. United Nations Human Settlements Programme.

International Energy Agency. (2022). Energy access and technical support in rural areas. IEA Publications.

Clean Cooking Alliance. (2023). Investment and impact in the clean cooking sector. Clean Cooking Alliance Annual Report.

Indoor Air Journal. (2022). Daily PM2.5 exposure patterns in rural households. Indoor Air, 32(3), e13012.

Same Sky. (2025). Thermoelectric generator module selection guide. DigiKey Electronics.

Encyclopedia Britannica. (n.d.). Thermoelectric power generator. Retrieved from https://www.britannica.com/technology/thermoelectric-power-generator