web analytics
Height of chimney - Forno Bravo Forum: The Wood-Fired Oven Community


1 of 2 < >


Hello, Forno Bravo Community Forum members.

As many may have noticed already, the Community Forum site was briefly down today. While working on scheduled routine maintenance, we encountered an error when trying to add a software update. As the site is now back up and running, some of you may notice that some recent data has been misplaced from November 10th up to today. We are currently working on resolving the issue. The forum has full operational capabilities and we encourage all forum members to continue actively posting in the threads.

We apologize for any inconvenience that this issue may have caused you. The Forno Bravo family values each and every member of our community. If you have any issues or concerns, please feel free to let us know on our issues thread here:


Thank you for understanding.
2 of 2 < >

Forno Bravo Forum Thread Message

Hello, Forno Bravo Community Forum Members!

The Forno Bravo team has heard the feedback in regards to the community forum. We wanted to take the time to re-enforce our commitment to a fully engaged Forum with professional moderation.

Our top priority as a company is to fix all forum errors and issues that you are experiencing. As we are swiftly working on these problems, we want to say that we highly value the Forum Bravo Community Forum and every single community forum member.

We have set up this thread so that every member can address any concerns, issues and questions about the forum. Please feel free to ask whatever you would like in regards to the forum; let us know what issues you are experiencing so we can work on resolving them as fast as possible. However, we stress that we would like constructive engagement, so please be specific about the issue you are experiencing.

Thank you for all of your patience and continued support.

Link to topic: http://www.fornobravo.com/community/...with-new-forum
See more
See less

Height of chimney

  • Filter
  • Time
  • Show
Clear All
new posts

  • Height of chimney

    I am building a 36 inch dome This will be outside Is there an optimal height for the chimney stack The lower profile the better for my site. Any thoughts ?

  • #2
    Oven chimney height

    In general, pizza ovens draw very well, so the pull of the chimney isn't a huge issue. For our Casa precast ovens, we recommend a 6" system for the 31" and 35" oven and 8" for 39" and 43" ovens. If you are going to use a UL103HT chimney system (double wall steel), the top of the chimney should be 24" above the top of the enclosure -- that is what Simpson Duravent specifies in their UL-approved installation manual. In terms of height, a 36" pipe, attached to the top of an oven vent will typically draw well, and rise above the top of the enclosure to the correct height.

    If anyone is interested, Forno Bravo is a Simpson dealer, and we can provide the chimney set -- an anchor place, chimney section and cap/spark arrestor. You can also download the UL103HT installation manual (and UL spec) from our web site.

    Pizza Ovens
    Outdoor Fireplaces


    • #3
      Re: Height of chimney

      I know its been a while since you posted this info about Chimney height, but I am about to install a terracotta pipe chimney which is 6" inside diameter x 24" long plus the cap. My round oven is 36" inside diameter with a 19" ceiling height inside. Will that cause me some problems? The pipe will be fully bricked in. Also even though your FB specs call for 6" pipe, many of the posts recommend 8" instead even for the 36" oven.
      Any thoughts?
      Jim Bob


      • #4
        Re: Height of chimney

        If you search the forum for Chimney flow rate you will find a calculator for the draw of the chimney. Using your numbers ( 6 inch pipe) I get a draw of 358. We only have a little data but the smallest reported sucessful draw rate is 645. If you increase your pipe to 8 in you will get a draw of 648 which we are sure will work. The 6 inch may work but its a little hard to tell since we have such limited data.
        A few people have mentioned the transistion being important to the draw of the oven. However, now matter your transistion, if your chimney sucks like a vacuum cleaner on steriods, smoke is going to exit via the chimney.
        Maybe we can get a few more people to tell us the size, shape and height of thier chimineys with an opinion about draw to refine the minimum flow rate. Here is a link to the calculator.

        Sharpei Diem.....Seize the wrinkle dog


        • #5
          Re: Height of chimney

          Thanks very much for the help. You have helped me avoid the mistake of too small a chimney. Will change to 8" pipe. Of course in order to use your very simple calculator I will have to dig up my metric conversion kit again. The final resulting number is just that a number, however, you have given us the minimum accepted one and that will be fine with me. I don't want to know too much or someone will start asking me what it means!!!
          Jim Bob


          • #6
            Re: Height of chimney

            After Extensive inquiries into various available flue liners it is now obvious that we are NOT talking about 8" x 8" inside diameter for the flue. That is the outside diameter and it is 6" x 6" inside diameter. Four major brick companies in Memphis say that what they list as an 8 x 8 liner is based loosely on the outside diameter and the inside is 6 x 6. The next size available up is 13" x 13" outside diameter, which is too big. So, I may already have the appropriate size after all.
            Jim Bob


            • #7
              Re: Height of chimney

              Hi Jim Bob,
              Why not use an 8" stainless steel flue instead of a terracotta?
              Much cheaper, easy to get, work well, need I elaborate further?
              I have a 40" Pompeii and my 8" flue which is 3 metre tall (to get any smoke on light up above the neighbours), has a draw value from an oven temp of 50˚C of 514.1 and when it is 500˚C, that value goes up to 1329.3.
              Don't ask me what that means but I know it works an absolute treat and no smoke at all escapes from the front arch. A smaller chimney will not cope with the load put upon it and have start up smoke coming out the front. (The forum is trying to find out the minimum value when this does not occur).

              Prevention is better than cure, - do it right the first time!

              The more I learn, the more I realise how little I know

              Neillís Pompeiii #1
              Neillís kitchen underway


              • #8
                Re: Height of chimney

                Thanks for feedback. I went shopping again yesterday and found a larger terra cotta flue liner. It is an 8.5" x 8.5" x 24" long. The 8.5" is measured diagonally and is the inside diameter. No wonder I couldn't locate the larger one, i had no idea they were talking about diagonal measurements. Hopefully this will do the trick. I was also lucky enough to locate a nice "bird cage" type cap for the liner that fits at a local fireplace store. So it will be installed tomorrow.
                I just wish everyone would go back to Fahrenheit and inches instead of Centigrade and metric. I am too old to change now!! Have to keep looking up the conversion chart! Unless my numbers are way off, a 3 meter chimney is almost 10' tall!!! Where did I go wrong? Mine is only
                24" tall.
                Jim Bob