You would be amazed at how much air gets sucked in through those two vents. Sometimes, they almost whistle when fully open ! Smokey the Bear tells us three elements are needed for fire: *fuel, heat, and air. If enough fuel and heat combine, they will find the air they need. (witness the burning warehouses during the riots…seemingly all locked up…flames rising high above. Probable a smashed window or two provided all the air needed for those huge flames.)
In retrospect, I likely would have gone with slightly larger vents, but I like the visual effect on the front of my door with these. And they function well…
I’ll build the fire over the firebrick where the pizzas will be “staged”, …then, fire-raging, I’ll push it all to the back, load in the pizzas, close the entry with my door, vents wide-open.
The fire/embers suck all the air they need to keep going. Checking on the pizzas once or twice allows a lot more air in, and the fire usually kicks up again. >>>Crust almost done, I will replace the door, AND close up the vents. So, we’ve got the direct heat from the burning wood, we’ve got the radiant heat from the firebrick…and we’ve now trapped the convection heat in the smoke, as it hovers over the pizza surfaces, “toasting” the toppings, before this proverbial “smoke goes up the chimney”. NOTE: the old iron door that came with the kit had been cut down to snugly fit into the oven opening, with an oven rope wrapped around, secured with high heat caulk/mortar. Virtually NO smoke comes out the front when the door is snugly in place…thus encouraging this "convection. So the veneer stays pretty clean, as well. I like that.
This door is actually composed of four “layers”: the outside is Western Red Cedar planking (the stuff you might line your closet with), screwed/glued onto a 3/8" plywood back (those little wooden plugs hide the screws); left over ceramic blanket from oven construction is between the wood and the old metal door (cut down to fit inside). Oven rope secures a very tight seal.
Built in May, the door has been employed in - probably - the production of 25 -30 pizzas in the past three months. No signs of structural issues or flaws.