Enhancing post-harvest sustainability in temperate crops through smart IoT-integrated indirect solar dryer

Post-harvest losses of fruits and vegetables, largely due to their high moisture content, pose a significant challenge in agriculture. Traditional drying methods, such as direct sun exposure, often result in contamination, quality degradation, and inefficient drying. This study presents the design and development of a smart IoT-enabled indirect solar dryer that not only automates the drying process but also introduces a crop-specific control system, allowing users to input precise temperature settings based on the type of crop. This capability ensures optimal drying conditions tailored to individual produce, enhancing nutritional preservation and reducing over-drying risks. The system integrates real-time cloud-based monitoring via IoT, enabling remote supervision and data analytics for temperature and airflow control. Experimental results demonstrate the system's effectiveness, achieving an average airflow of 3.0 m/s, an average solar collector temperature of 57 °C, and a stable 45 °C in the drying chamber. Compared to traditional dryers, this setup significantly reduces drying time, minimizes contamination risks, and offers higher precision and flexibility. These advancements contribute to improved scalability, sustainability, and usability in post-harvest management, especially for small and medium-scale farmers.