The Sun-Funnel cooker, designed by Teong Tan, is similar to the Fun-Panel cooker, but with a different panel fold. The revised panel fold is necessary in order to form a rigid cooker base that is strong enough to support the cooking pot in an elevated, but more advantageous, position.
A stick, which traverses the lower section of the cooker, is added so that the cooking pot can be placed, as horizontally as possible, even after the cooker has been repositioned at a different pitch angle. This means that the cooker and the pot can now be easily repositioned to track the sun’s movement for a more efficient cooking throughout the day.
The cooker can be constructed, in less than an hour, from a used cardboard box, a stick, some aluminum foil and some homemade glue. The size of the Sun-Funnel is suitable for use with a 4-liter size black metal pot that has a tight fitting clear glass lid. A plastic oven bag can be used as a greenhouse enclosure for the pot, if a black metal lid is to be used instead of a clear glass lid, or when a higher cooking temperature is desired.
The plans and constructions steps for the Sun-Funnel cooker are provided here: Sun-Funnel Cooker Construction Plans