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Vent at front

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  • Vent at front

    Thank you you all for your feedback on the last design! As a result of this feedback and reading the forum I have totally redesigned the oven so that it will perform better. I have made two major changes and quite a few others as well. These are listed below and I have also posted drawings of the new oven. The major changes:

    1. The flue has been moved to the front (from the back).
    2. I made the entrance much smaller, the entry arch is now 500 wide and 300 high.

    Other changes include:

    3. The dome starts from the structural stand and for the first three courses (below the cooking floor) we will use insulating fire bricks. It is hoped that these bricks will prevent heat loss into the structural stand. I have been recommended 26 grade insulating bricks as they have a higher density and will hold the dome up.

    4. One inch fire bricks for the cooking floor with 200mm of loose vermiculite below.

    5. Cooking floor raised 50mm to 1.15m. This is to increase the space below the cooking floor to 200mm (more room for insulation), to make the oven more accessible, and for safety as hot gasses will exit the dome higher.

    6. The flue uses a steel hood to free up the area in front of the fire door.

    7. The steel hood can be unbolted from the oven if we need to redo the insulation under the cooking floor (also remove a couple of bricks).

    8. The steel hood reduces the size of the oven entry at the top so we don?t loose so much heat and can still see inside, and is wider at the bottom for pizza access (pizza access space is 500*100).

    9. We have the option of building and using the oven without a front flu and getting one made up in the future.

    10. The flue will hang from the arch which have ties to the outer concrete dome.

    Feedback on this new design will be appreciated (also see posted cross section and perspectives, links below).

    Also I have some questions:

    I am concerned about about people getting burnt by hot gasses exiting the dome, is this ever an issue?

    Do insulating fire bricks absorb water?

    This oven is being built on an intention community in western Australia to cook food at functions. The community is 15 houses in size and the oven will be built at our communal building where it will bring people together to eat tasty food. We do this already with pancakes and have found this to be a community building activity. There are lots of advantages to having healthy community's including more friends to help each other, better decision making as a group and more effective dissemination of handy ideas. A health community can also mean a reduced crime isolation and depression. Pizza ovens could have an important role in building community, have people found this to be true?
    Ps the guy in the perspective drawing is 1.6m tall

    Link to perspectives and cross section.
    PhotoPlog - Error
    PhotoPlog - Error
    PhotoPlog - Error

  • #2
    Re: Vent at front

    just one thought: the hearth tiles could advantageously be 2 in (50 mm) thick... (mine are, and the floor loads up with heat very well :-))


    "I started out with nothing, and I've still got most of it"


    • #3
      Re: Vent at front

      Loose vermiculite is very soft and fluffy. Bricks laid directly on loose vermiculite are unlikely to remain flat. Remember: you're throwing logs into a hot firing chamber, and horsing them around with various tools. I'd do a test of this with your materials when you get them in hand before making this decision.

      It's not that hard to make vermiculite concrete.
      My geodesic oven project: part 1, part 2


      • #4
        Re: Vent at front

        Originally posted by JayP View Post
        I am concerned about about people getting burnt by hot gasses exiting the dome, is this ever an issue?
        It's only an issue for the person doing the cooking. And then, only when you put your hands and arms in the oven. Use a long leather welders gloves for protection (or enjoy having red, hairless arms ).

        Right outside the opening is actually very cool because the exhaust gasses are going up the chimney.
        Ken H. - Kentucky
        42" Pompeii

        Pompeii Oven Construction Video Updated!

        Oven Thread ... Enclosure Thread
        Cost Spreadsheet ... Picasa Web Album


        • #5
          Re: Vent at front

          yea, I was wondering about the tiles staying flat. Thought we could throw some corrugated tin on the vermiculite then put the floor of that. Don't know if the tin will take the heat though.


          • #6
            Re: Vent at front

            The links didn't work in the original post. Trying again...

            PhotoPlog - Error
            PhotoPlog - Error
            PhotoPlog - Error

            or (links straight to jpg's)

            Last edited by JayP; 02-27-2008, 08:04 PM. Reason: missed a bit