Insulation; Apparently a Must Have for a Solar Cooker

While I scour the internet looking for resources of cheap ideas to get my solar oven cranked up as high as she can go, one common topic keeps popping up; Insulation.

Now insulation is something that I naively ignored in my very basic solar oven, assuming that with the summer temps here in the desert, it would not be an issue. It appears I was dead wrong. As soon as the sun drifts behind the shade of a tree in the late afternoon - BAM! the temp in my solar oven drops below the 150 degree (F) bottom end threshold for my thermometer.

A simple foil lined outer box seems to be sufficient, with at least a 1/2 in gap between the inner and outer boxes (bottom too). Air alone seems to work just fine, but others have filled the gap with sand, dry soil, newspaper and "gasp", Styrofoam.

My mission as it stands right now will continue to be to see how hot we can crank up this solar oven, and I believe the next upgrade will be fitting a "Heaven's Flame" style reflector to it..

But food for thought .... if you intend to do any real cooking beyond reheating, the consensus seems to be that insulation is of the utmost importance. Funny how right now that still appears to be last on my list.