heat transfer from a sealed box exposed to the sun

these days you will notice outdoor electronic boxes all over the place. without these wonderful little boxes we couldn't use our cell phones and will be deprived of a lot of high tech. stuff. an outdoor box is usually exposed to the sun which plays an important role in the radiation heat transfer.

you can use this calculator to estimate the surface temperature of an outdoor box. the situation can be depicted below:

heat is generated inside the cabinet and will be transferred to the wall bu convection (ignore internal radiation or lump it into an internal heat transfer coefficient). the outside surfaces (sunny side as well as the shaded side) exchange heat with the ambient by radiation and convection.

the claculator uses energy balance at the three nodes of tom, ti and ts to estimate the values of the above quantities.