I had an interesting conversation with our dealer/installer in Oregon, who is building his first Forno Bravo oven, about insulation and different types of heat transfer. I am interesting in hearing everyone's feedback on this. Alf -- let me know what you think.

The basic theory is that conductive and radiant heat work differently, and that while Insulfrax and Vermiculite do a good job of stopping conductive heat, there is still some radiant heat energy that makes it through the 5" insulating schedule. By adding a layer of foil on the inside of the enclosure walls, around the insulation, you can gain a little insulating efficiency. It's basically cheap and easy to do, and will add some insulating value.

Brad's theory (I hope I am getting this right) is that radiant heat is able to work its way through the insulation and would be reflect back into the insulation, helping keep the oven chamber warm. The impact wouldn't be huge, but worth it.

The thermal computer model showed that at equilibrium the the outer face of the vermiculite won't go higher than roughly 170F, using a 1000F oven face as the test surface.

What does everyone think?
James