Chimney/Flue Size for Steel Oven

[Oven_Man]

Hi Guys

I am building a steel oven and would like to know what diameter Chimney should I get as well as how close to oven entrance should I place the Flue Pipe?

Oven DImensions
Opening - 18.5"
Oven Length - 32"
Height: 9"

Thanks

[david s]

The flue diameter required is dependant on the design. Eg a simple updraft flue requires a much smaller diameter flue than a typical cross draft front flue design favoured by mist oven builders here. Secondly the flue diameter requirement is largely dependent on the oven volume. As a guide a 36” diameter hemispherical oven requires a 6” flue pipe. As you haven’t given all your oven dimensions it’s impossible to compare volumes.

[Oven_Man]

Hi David

Thanks for responding.

I'm going for the Ooni Pro Styled Oven. I've adjusted my dimensions and the oven chamber size is 70cm X 70cm and height is 30cm.
I'm placing a removable oven door with a cutout, large enough to get my peel in and out of the oven. The cutout will be 18cm height but I'm not sure what length the mouth of the opening should be - 40cm perhaps?

Thanks

[david s]

You will need to get the correct thickness stainless for the inner stainless vault that will be subjected to fire. Thin stainless warps like crazy. You’ll also need to insulate it with ceramic fibre blanket. Not sure how much the ooni uses.

[MarkJerling]

Hi David

Thanks for responding.

I'm going for the Ooni Pro Styled Oven. I've adjusted my dimensions and the oven chamber size is 70cm X 70cm and height is 30cm.
I'm placing a removable oven door with a cutout, large enough to get my peel in and out of the oven. The cutout will be 18cm height but I'm not sure what length the mouth of the opening should be - 40cm perhaps?

Thanks

Are you buying an Ooni Pro? If so, the come with a flue. Or are you copying their design?

[Oven_Man]

David_s - I'm using 1.2mm Thick Stainless Steel for the inner done with 75mm Ceramic Fibre Insulation between the 2 domes.

Mark, I'm doing a similar design to the Ooni Pro.

[MarkJerling]

Aha, thanks for clarifying.

[david s]

I have no experience with this style of oven, but I think you’re on the right track. Don’t forget to include underfloor insulation. I think a 6” diam flue sounds about the right size. You will need to include a shut off butterfly valve in the base of the flue pipe (because it’s an updraft system with the pipe in the oven chamber) for baking and roasting.

[Oven_Man]

Thanks David - i will go with your guidance.

Another question I have - my oven internal size if 700mm X 700mm and 330mm(Internal Dome Height) - My oven entrance is 400mm Width X 200mm Height. Are these numbers in accordance with the guidelines set out - I tried my best to keep them as tight to the guidelines as possible.