height of transition to anchor plate

[waynebergman]

Starting to cut some of my transition bricks to go from the brick vent opening to the anchor plate. I have a 6" pipe and a 36 inch internal sized oven. I am wondering about the height of transition area to anchor plate. I see Ken has quite a large space in there and others are shorter. Is there an ideal number? Mine will be about only 4 inches from top of arch vent to anchor plate and then I have 3 feet of pipe for my chimney. Does this sound OK? I choose 4 inches as it will make the job easy but I can make it higher if necessary....thanks wayne

[wlively]

How wide is your vent opening?

For better air flow, you want the transition as smooth as possible. Large angles induce higher friction losses and turbulent flow. I would definitely not have an angle sharper than 45 degrees.

[RTflorida]

Just my two cents...Yours looks almost identical to what I did. I used the same 6" pipe - 4' length. At the time of my build there was not as much talk of lessoning the angles and having a progressive transition; so what you have pictured has been done, and works. The only difference is that I flattened the tops of my arch bricks to have a flat surface for the anchor plate to mate to.
That said, could mine draw better? - probably. Do I get smoke in the face? - only with poor kindling on start up. Seems to draw fine, although I have nothing to compare it to. I'm happy, guess thats all that matters.

RT

[Ken524]

Hi Wayne,

Your work is spectacular. You're oven is lookin' fabulous.

My vent transition was not built according to any sort of master plan, it just worked out that way. I had to transition from wide & skinny to an 8" x 8" opening for the anchor. My transition angles are just continuations from the angles I cut inside my vent.

I'm pretty sure I read somewhere that a larger, boxy transition like mine will heat up and create a better draw. It does draw very nicely, but like others, I have nothing to compare it to.

Your vent looks very similar to mine. I would box it up, mount the anchor and fire it up!

[waynebergman]

Thanks so far guys. This helps. Wade to answer you question the bottom opening is about 14 inches wide at the under side of opening and the depth is 5 1/4 inches. The attachment hear shows 2 sloping pieces I will mortar in tomorow to transition from this 14 inch width to about 9" at the top of vent. At this point I plan to mortar in the anchor plate and brick in the front and back of things also.....wayne

[wlively]

Wayne

Sometimes I tend to over analyze things from an engineering perspective for what would work the absolute best. We have to remind ourselves that this is not rocket science and it won't take much for these ovens to work.
I am sure I went a bit overboard with my custom high tech shaped plug and cast vent. But, it is comforting to see the smoke that is outside the vent opening and headed straight out of the arch, make a rapid 180 degree turn and go up the vent.

That being said, the transition you gave would be roughly 5 inches over a height of 4 inches would work. Taller would work better. It is just what do you want to do; keep it simple, asthetics, or best possible draw.