How does a solar cooker trap heat?
Greetings Cherie Ann,
Thank you for your solar cooking question.
A solar cooker does have to trap or retain heat in order to work effectively, otherwise the temperatures would only rise so far and would not be sufficient to actually cook food.
But, the question: How to trap the heat generated from the energy of the sun's rays?
Some people show plastic being used for the glazing (cover) of a solar cooker such as the pizza box solar cooker, but plastic can melt very easily and usually shrivels up when hot, so it is not the best choice for covering or lid on a solar box cooker. Of course you can use an Oven Roasting (turkey) bag to trap the heat in your solar box or panel cooker. These bags are designed and manufactured to withstand heat and to not "0ff-gas" when hot. Here you can see how a bag is used in a simple solar panel cooker
For most solar box cookers you would want to use a glazing that does not melt or break easily, preferably something like tempered glass.
There is much more that can be suggested and discussed with regards to how to trap and retain the suns energy in a solar cooker so we suggest you also look at some more of our site pages and outgoing links on our site that can direct you to more helpful information.