Performance Evaluation of Box-Type Solar Cookers Using Different Insulation Materials

Abstract

This study investigates the thermal performance of solar box cookers developed using sawdust, chicken feather, and groundnut shell, respectively as insulation materials. Stagnation tests and load tests were carried out to evaluate the cooker performance by determining first figure of merit (F₁), cooking power, standardized cooking power and the thermal efficiency of the developed cookers. The F₁ values for cookers A (which served as the control), B (sawdust), C (chicken feather) and D (groundnut shell) were found to be 0.099 °C m²/W, 0.129 °C m²/W, 0.114°C m²/W and 0.111°C m²/W, respectively. The standardized cooking power at 50⁰C temperature difference for cookers B, C, and D were 42. 25W, 37.26W and 35. 25 W, respectively. Statistical analysis showed that the regression for cookers B and D have a good fit. Cooker C, however, has an R² value of less than 75%; the variation in the cooking power, therefore, cannot be explained by temperature difference. The overall thermal performance of the cookers B, C, D were reported as 25. 46%, 23.51% and 24.0%, respectively. The study concludes that effective utilization of a material with good thermal insulation property contributes significant roles in improving the cooking performance of the cooker.