How to minimize the energy looses ?

Now that we studied what were the means to collect a maximum of solar energy, we are going to study means to minimize the losses of energy inside the oven. Knowing that the transfers of heat towards the outside can be made by radiation, conduction and convection, we shall approach this second part in a slightly different way, by trying to analyze how are limited these three ways of transfer of heat through the elements which constitute the oven.