Oven & Vent Opening Size

[Hendo]

Many pictures and oven designs (including those at Pompeii) show a vent arch higher than the height of the oven opening. Surely this would encourage combustion products from the oven to exit through the vent arch, rather than solely via the chimney? Would it not be better for the height of the vent arch to be the same as the oven opening? Of course it cannot be lower as there needs to be sufficient access to place a door over the oven opening, but surely the same height would create a more efficient draw?

[redbricknick]

Hendo. Mate. calm down. I think most ovens are designed from the standpoint of cooking performance rather than exit flow of combustion product efficiency. From what I have come to understand about brick ovens, if they are working correctly, the smokiness only lasts a little bit while the oven is getting up to temperature. But if you can draw a picture of how to make the ancient pompeiian's designs work better, I'll give it a bash.