Effect of aspect ratio on thermoelectric system performance for waste heat recovery as alternative energy in building

• This works investigate new design and effect of aspect ratio in negative leg. • The material used are different in positive leg. • The heat source from kitchen hoods for waste heat recovery as alternative energy. The increasing global energy demand and the shift towards renewable energy sources underscore the importance of utilizing wasted energy. Thermoelectric technology presents a viable solution by converting this wasted thermal energy into alternative electrical power. Consequently, thermoelectric applications have been extensively researched and explored. This study investigates the effect of the aspect ratio of sandwich thermoelectric legs on the performance of thermal energy recovery in a kitchen hood. This is important because waste heat generated during cooking is a large and readily available but often untapped energy source. Recovering and converting this waste heat into usable electricity can contribute to energy savings and reduce the overall environmental impact of cooking activities. This research was conducted using a numerical computation method using ANSYS software. The heat source utilized is the heat from cooking activities that is channeled to kitchen hoods. The cold temperature is channeled outside the ducting which is then made a cross-section with a heat flow in the middle of which is given thermoelectricity. The resulting electrical potential is analyzed and the influence of the materials used is further investigated. The results show that Bi 2 Te 3 has higher power due to its superior electrical conductivity. The Bi90AB configuration achieved a maximum output power of 11.19 Watts at a temperature difference of 90 °C, converting 6713 Watts of heat into electricity. The temperature distribution and voltage gradient were shown to be important for efficient energy conversion. The higher voltage gradient in Bi 2 Te 3 reduces power generation due to the imbalance of the positive and negative legs. This research advances previous work by focusing on the application of thermoelectric generator in kitchen hoods and optimizing the aspect ratio. This study provides design considerations to maximize power output and efficiency, as well as supporting more sustainable kitchen equipment. Further research can explore nanofluid-based cooling systems to improve performance, and experiments are also recommended.