Comparative Analysis of Traditional and Solar Drying Techniques for Red Chilli

This study compared the performance of direct solar dryer, indirect solar dryer, and opensun drying methods for red chilli. The solar dryers consisted of collectors, drying chambers, and airflow systems, while open-sun drying involved spreading chilies on polyethylene sheets under direct sunlight. Drying occurred from 9:00 am to 3:00 pm until the desired moisture content was reached. Average ambient conditions included a temperature of 31.04°C, relative humidity of 63.68%, air velocity of 3.45 m/s, and solar radiation of 365 W/m². The highest temperature was recorded in the direct solar dryer (57.6°C), followed by the indirect solar dryer (55.4°C) and open-sun drying (38.1°C). The direct solar dryer had the lowest relative humidity (41.2%) compared to the indirect solar dryer (43.1%) and open-sun drying (53.2%). Solar radiation was lowest in the indirect solar dryer (230 W/m²). Drying time was 32 hours for the direct solar dryer, 36 hours for the indirect solar dryer, and 50 hours for open-sun drying. The highest drying rate (6.1 g/hr) was observed in the direct solar dryer, followed by the indirect solar dryer (5.9 g/hr) and open-sun drying (2.4 g/hr). The direct solar dryer proved to be the fastest and most efficient for drying red chili while maintaining quality.