Barrel oven build?

[ceeyahd1]

How do you determine where to end the arch and start the transition? I have around 18" from the end of the arch to the door opening, do I go 1/2 brick, full brick then start the transition, I have 3 full rows of bricks already on my dome?

I used the 63% formula to determine door opening height, I have 19" dome height and 12" door opening height, my oven is 40"W X 42"D, I noticed yesterday if I go 12.5" door opening I have a clear view all the way to the back of the oven compared to 12" height, 1/2" seems to make a big difference. Would it be OK to go 12.5" on door opening without causing any issues with venting since it will be 65% and not the recommended 63%?

Thanks

[Tscarborough]

Re: Barrel oven build?

There is no need for a transition, the inner arch can butt to the vault at a right angle. You should, however, cut a revel into the end wall brick so that there is a keyed joint.

[Tscarborough]

Re: Barrel oven build?

No matter what you do, you need to maintain the integrity of the dome longitudinally. As you have it, there is a joint there. You need to tooth out the leading edge of where you are, which will mean removing some brick.

[SableSprings]

Re: Barrel oven build?

I used the 63% formula to determine door opening height, I have 19" dome height and 12" door opening height, my oven is 40"W X 42"D, I noticed yesterday if I go 12.5" door opening I have a clear view all the way to the back of the oven compared to 12" height, 1/2" seems to make a big difference. Would it be OK to go 12.5" on door opening without causing any issues with venting since it will be 65% and not the recommended 63%?

Thanks

The 63% figure was created based on the draft/flow/venting efficiency data from a wide variety of working WFOs. The number was developed simply to provide a guideline for WFO builders...not to establish an absolute requirement. You can deviate a bit from 63% (both directions) and have a functioning oven. My oven is a Pompeii/Beavertail style (39" wide/45" deep) with a 20" dome height and 11.75" door height opening...lower than optimum at 58.75%. I can bake bread, pizza, turkeys, roasts, cookies, biscotti, & souffles, etc. with no problems. I might have had a more technically efficient oven with a 63% opening...but I have no problems or regrets. My opinion is that the extra 1/2" for your opening won't create a draft/flow/venting problem (as long as you provide a smooth exit path/throat and adequate chimney volume) and if you like having the clear view to the back...go for it!

[ceeyahd1]

Re: Barrel oven build?

Thanks for the replies. My main question was regarding the transition to the opening, I was not sure where to start it, TS car borough suggested to go straight out to the opening without a transition, I thought the transition had something to do with the venting so I am stuck until I figure out the best way to do this. I plan to use 8" chimney tube.

[Art nj]

Re: Barrel oven build?

Hello, I built a barrel recently and had the same issue, I had 3 rows of bricks and started the transition down towards the door.ill try to attach a picture of what I did.
Art

[Tscarborough]

Re: Barrel oven build?

The transition is a vestige of the Alan Scott design, and serves no purpose other than to complicate the build.

[theDarbster]

Re: Barrel oven build?

Tscarborough, I thought you needed to transition from the top of the dome down to a lower door height for proper heating of the oven... the 63% recommendation.

[Tscarborough]

Re: Barrel oven build?

The ratio is between ceiling height and inner arch opening height. There is no need for a transition between them.

[v12spirit]

Re: Barrel oven build?

The ratio is between ceiling height and inner arch opening height. There is no need for a transition between them.

May be those who insist on the transition are taking into account that the barrel vault -having no longitudinal curvature- needs it to smooth air flow over the opening arch, something you don't even have to worry about in Pompei style rounded ovens..

BTW, I'm still failing to understand how this "generously" vented Barrel vault oven can maintain a proper heating: