firebrick arch vent question

[gjbingham]

Re: firebrick arch vent question

David S. - I concur completely. Master Christo's teachings inspire us to embrace our smoke stains. I finally relaxed and have only cleaned mine once, and that might be the last time.

[chertupper]

dampers and doors

Wade, hi.

We are total newbies at the forum. Hope we're not breaking etiquette to directly ask you a question, rather than posting it. Anyway, saw your comments ...
Re: firebrick arch vent question ...

and want to ask your opinion of dampers and doors. We're building a 42" oven for our cafe in Arizona and are about to order the chimney pipe and oven door.

Do you think installing a damper is a good idea? Or rather would it interfere with the air flow?

Also, can you point us in the direction of some information about oven door installation and how it impacts what you can do with the oven? We want to bake bread as well as pizza and heard that you put doors in both the inner and outer arches of the entry tunnel.

Thank you in advance for your reply, Cheryl & Gary

I doesn't matter much as to how high the arches relative to each other. It is more importantt to get the dimesions and "flow" of the hot gas correct.

As a precaution I made my outside arch 1/2" lower than the entry, but it turned out insignificant. IMHO you want the chimney opening in the arch as wide as possible and no sharp corners. You want to make it easy for the smoke to flow out and into the chimney, so corner cut or round off the hot side of the chimney entry opening. The chimney opening in the arch should be larger area than the area of the the chimney itself as you want to increase the gas velocity which decreases air pressure to increase draw. You want to make a smooth path for exhaust flow, sharp corners creates turbulence which slows flow. The taller the chimney the better the draw, but not by a large number in our application.

You can also just set a pipe over a square hole and it will work. But if you decide you want to have the best drawing chimney you can build, then like the rest of the oven it will take some planning and work as well.