Identifying the Ideal Configuration of a Solar Greenhouse Dryer Suitable for Mushroom Drying

In this study, a solar greenhouse dryer (SGHD) configuration was optimized to overcome the limitations of conventional hot air drying, where the delicate tissue structure of mushrooms is often compromised, leading to inferior product quality. The optimization focused on enhancing airflow and temperature distribution through various design configurations. Four SGHD designs were analyzed using computational fluid dynamics (CFD) simulations and experimental validation in Solan, India. A side air outlet caused significant temperature variations (±4.39°C) and uneven airflow, leading to localized overheating. A top-mounted inlet fan improved circulation but still showed fluctuations (±4.27°C). A zigzag airflow diversion design increased air flow resistance, causing inconsistencies (±4.40°C). The most efficient design, featuring a conical roof with a top-center air outlet and shed net covering, achieved the lowest temperature variation (±1.65°C). In this design, maximum chamber temperatures of 44°C (passive mode) and 37.5°C (forced convection mode) were recorded. Improved airflow regulation prevented overheating, enhancing color retention (L = 56.98, ∆E reduction of 7.94), and rehydration capacity (3.44). Economic analysis showed an annual drying cost of ₹63.42 per kg, with a 2.9-year payback period and cumulative savings of ₹68,825 over 7 years. The conical-roof SGHD design offers a cost-effective, energy-efficient, and sustainable solution for high-quality mushroom dehydration.