Nope, only the fire box in the calculation & it's only the internal volume so decreasing the internal size with bricks or an insulated double wall will work to get your ratio back to about 105%, with the added bonus of being more fuel efficient.
Let's start this over from the beginning if you don't mind. You plug in the dimensions of your CC and the dimensions of your FB measuring the inside only after the brick has been installed. The calculator will tell you if the box is right or not. Now you mentioned the WC above the FB it's size doesn't have any effect on the size of your FB. But if you want to cook in it, there are some things to consider. 1. The radiant heat coming from the top of the FB probably is not enough to cook with but a bit too hot to just keep things warm without allowing cool air in some where into the WC. So some people make an air gap between the top of the FB and an additional plate that becomes the bottom of the WC. Once this idea comes into the plan it can go insulated instead of just an air gap. Either way now you're not being forced by radiant heat to adjust things you can now choose to add an opening from the FB to the WC and you just gained an awesome CC of which can run at a totally different temperature than the other without changing the flow of the main CC.
Ok yes I have been a bit addicted to this stuff for a while but admitting it is the first step right?
I said all this to say you can do almost anything with the design you have begun don't stop by trying to figure it out alone. I added a GF to mine too so there's really no limit until you stop working on it.
Making memories!
Current Smokers: Backyard RF Offset and Hybrid RF Offset trailer rig with Cowboy cooker and fish fryer, always room for more........
Thanks for your suggestion. That's exactly along the lines of what Im wanting to do I've seen some really neat pits with removable plate between FB and WC . They also had butterfly valves so you could totally control the heat in WC for cooking or remove the steel plate between and use WC as a smaller wood fire oven/ pizza oven. It was because of wanting to do this it increased the size my FB would be and the calculate said the FB was to big
How cool would it be to have an actual pizza oven on top of firebox. So I am thinking about a 24 inch end bell off a propane tank that evolves from the round bell into the square firebox.
You got it. Something like that if what I've drawn up also . And have adjustable slots for the fire grate to be raised just above the throat of the main CC so most of the heat purely heating the pizza oven when you only wanting to use that
Yes but the ovens I have seen have the heat source entering the oven from one side. Such as close up against the cc side. Heat wants to flow into the cc by design. Therefore it would be only natural to flow good going up into the PO (pizza oven).
Your stone is preheated.
Heat enters from the transfer tube , rising and following the curve of the dome and wal-laa , pizza is cooked from the top as well as the bottom.