Comparative analysis of the Performance of Solar Box Cookers with Kapok and Saw Dust Insulators

Abstract

The necessity for the search for available and affordable alternative source of energy to supplement the use of firewood for food cooking cannot be over emphasized. The present work is aimed at development of solar box cookers which employed two different natural thermal insulators namely Kapok wool and Saw dust, their performance evaluation were compared. The method employed was; the two thermal performance parameters called figures of merit (F₁ and F₂) associated with testing box-type solar cookers as per Bureau of Indian Standards (BIS). The First Figure of Merit, F₁, was determined from a stagnation test under no-load condition while the Second Figure of Merit, F₂, was determined from test under full-load condition, taking water as the load. The results obtained were subjected to statistical analysis using F-test, which clearly indicates that there are no significant differences in both the stagnation (no load) test (F₁) since F value is 1.116678 which is less than the F Critical value of 1.98376 at 5 % level of significance and 24 degree of freedom. And for the boiling (load) test (F2), the F Test value is 1.034856 which is less than the F Critical value of 2.576927 at 5 % level of significance and 13 degree of freedom for both cookers. The results for no load test (F₁) were found to be (0.123 Km²W^-1) and (0.124 Km²W^-1) for cookers with Kapok wool insulator and Saw dust insulator respectively, while results of the load test (F₂) were 0.057 and 0.056 for cooker with Kapok and Saw dust insulator respectively. The study on Kapok wool and Saw dust insulators reveals a promising future for the natural insulators in term of better insulation and low conduction losses and a better cooking ability of both cookers as the value obtained surpasses the standard given by Bureau of Indian Standards (BIS).