FABRICATION

This project focuses on the design and construction of a solar-powered food dryer aimed at improving the efficiency and sustainability of food preservation, particularly in off-grid and rural environments. The developed system utilizes solar energy as the primary heat source to dehydrate agricultural products, thereby reducing post-harvest losses and enhancing shelf life without reliance on fossil fuels or electricity from the grid. The dryer comprises a solar collector unit, drying chamber, air circulation system, Lagging material and insulated drying trays. The design emphasizes passive solar heating, which harnesses thermal energy from the sun to generate hot air that is circulated over the food products to facilitate moisture removal. To ensure uniform drying and improved airflow, Two DC-powered fan connected to a photovoltaic (PV) panel is integrated into the system. This setup enables consistent airflow and temperature regulation within the chamber during operation.The solar collector was oriented due south and inclined at 16.2°, based on the optimal slope calculated from the local latitude of Benin City. Design calculations showed a collector area of 0.17 m², drying chamber volume of 0.044 m³, and heat gain of 170 W/m², with heat loss through the chamber walls estimated at 8.9 W/m²K. Preliminary testing was conducted using sliced plantain to evaluate the drying performance in terms of moisture reduction rate, drying time, and product quality under typical October weather conditions. The internal dryer temperature ranged between 45°C and 65°C, consistently higher than ambient conditions. Moisture content reduced from approximately 100% to 39% (wet basis), corresponding to 0.075 kg amount of water removed. Effective drying occurred within 17–20 hours, significantly shorter than traditional open sun drying which typically exceeds 24 hours under similar conditions. The average drying rate was 0.0044 kg/hr, and the solar dryer achieved a high overall efficiency of 94.76%, indicating excellent heat utilization. Which is ideal for preserving color, texture, and nutrient quality of Agricultural Product. The findings demonstrate that the constructed solar dryer offers a practical and energy- efficient alternative for small-scale food processors and farmers, particularly in regions with high solar potential. This work contributes to the advancement of sustainable food processing technologies and provides a foundation for future improvements, including hybrid systems and thermal energy storage integration for continuous operation during low-sunlight periods.

This project report presents the design and fabrication of a domestic heat extractor using locally sourced materials. The aim is to develop a cost – effective and energy – efficient device capable of removing excess heat from domestic cooking areas, thereby improving thermal comfort and safety in homes, particularly in developing regions where ventilation and cooling systems are often inadequate. The project involves a detailed study of heat transfer principles, material selection and fabrication processes tailored to locally available resources. Components such as the extraction fan, heat duct, aluminum casing and power source were designed and assembled using affordable and easily obtainable materials. Performance evaluation showed that the fabricated heat extractor effectively reduced heat concentration in enclosed kitchen spaces, improving air circulation and thermal comfort. The outcome demonstrates that domestic engineering innovations can be achieved sustainably using local resources, contributing to environmental protection, cost reduction and industrial development.