Solar funnel cookers can be designed as attractive and affordable low-cost devices accessible to people in all
continents of the world regardless of their walk-in life. The present work is aimed to investigate the applicability
of funnel cookers to attain the temperature in excess of the boiling point of water. It widens their acceptability for
cooking and opens new opportunities for technological developments in such designs of solar cookers. Two
identical designs of funnel cookers, FC1 and FC2, have been tested with appropriately sized identical cooking
pots and glass enclosure to serve the purpose. Cooker FC2 is tested with a glass enclosure only, while a glass
enclosure is not used in FC1. Glycerine is used as a test load. Cooker Opto-thermal Ratio (COR) as a thermal
performance parameter and overall cooking efficiency are used to compare the performance of the two funnel
cookers. It is shown that the temperature of the test load in the cooker FC2 can reach 140 to 150 ◦C. So, this
funnel cooker design can be preferred for cooking food at a relatively high temperature over the boiling point of
water. The experimental results show that: i) the mean values of the Cooker Opto-thermal Ratio for cookers FC2
and FC1 are estimated to be 0.157 and 0.110 (m2◦C)/W, respectively, and ii) the values of the overall cooking
efficiency for cookers FC2 and FC1 are estimated to be 11.8% and 10.2%, respectively.
