The Wood-Fired Blog

Pizza Oven Design — Ventilation Options. Both Good and Bad.

Building on my postings the last couple of days on oven design and innovation, I wanted to follow up with some thoughts on pizza oven ventilation design. In general, there are a couple of different methods, including two that are quite widely  used, and a couple that you need to avoid —whether you are building your own oven, putting a pizza oven kit or assemble oven in your backyard, or selecting a pizza oven for your restaurant.

The two proper venting methods are the “traditional design”, where the vent is located in front of, and above, the oven opening, and the chimney (or ventilation pipe) runs vertically up from the vent; and there is the “center vent design”, where the vent (or hood) opening is located directly above the oven opening, and the vent runs directly back over the top of the oven dome, where it connects to the chimney (or ventilation pipe). In both cases, the ventilation system is located outside of the cooking chamber, where the door can be used to regulate airflow, or even cut off airflow, and to retain heat inside the oven.

The illustrations below show the elements and functionality of both designs. Be sure to click on the graphic to see a larger image.

Center vent closed


Center Vent Open

In the traditional wood oven ventilation design, the vent is located in front of, and above, the oven opening, and the chimney runs straight up. The vent and chimney create a strong draw, helping pull hot air out of the oven chamber and increasing the oven’s natural convection. While a wood oven will “work” without a vent and chimney, a properly designed oven ventilation system will significantly improve air movement and oven performance, while keeping smoke away from the chef. The traditional design can work either with, or without, side walls that enclose the vent.

The center vent design has also been been used widely over the years in both pizza ovens and bread ovens. Like the traditional ventilation design, the vent creates a strong draw, helping pull hot air out of the oven. Additionally, because the hot air is pulled directly across the the top of the oven dome, this ventilation design can help evenly heat the oven and help the dome maintain high pizza baking temperatures. The center vent design is used in Naples-style pizza ovens, where they often call the vent a hood, or second dome.

You really can’t go wrong with either design, and in some ways the question of which ventilation method works better for you may depend as much on design ascetics as it does on functionality. Forno Bravo manufactures ovens using both ventilation methods.

I also want to add a couple of thoughts on two other ventilation designs — the “no vent” oven and the “vent in the oven” designs.

There is a small oven imported from Portugal that is for sale in the US that does not have a vent, and to be blunt, we would strongly recommend against buying it. Given the choice of the Forno Bravo Primavera and Andiamo ovens (at very reasonable prices), there is no reason to buy a vent-less oven. The oven does not draw as well or operate as well as a properly designed oven, and the chef has to deal with constantly have smoke in his or her face.

We are also asked on occasion whether we would recommend a Pompeii oven builder avoid the hassle of building a vent, and our advice is that unless the vent will stop you from building your oven, it is absolutely worth the effort to build one.

And finally, there is the “vent in the oven” design where the vent is placed inside the oven opening, behind the oven door, rather than outside of the oven chamber. There are some shortcomings to this design, so there are two basic reasons for seeing an oven with an internal vent. First, you see an internal vent on Forno Bravo’s innovative Strada60 — our smallest and lightest oven designed for portability. By incorporating the vent inside the oven chamber, we were able to create an oven that you can easily set up at a tailgate party, that still provides excellent wood-fired cooking performance.

On the other hand, when you see an internal vent on a permanent oven you know there is  a problem. To be blunt again, in this case the oven designers simply did not know what they were doing. There are two different US-made pizza ovens that have this critical problem, one located in southern California and the other in Illinois, and our recommendation is to avoid those ovens.

Take a look at the graphic below to see the implications of an internal vent.

Door Location

Sorry about the lengthy post. Let us know if you can any questions or comments.


11 thoughts on “Pizza Oven Design — Ventilation Options. Both Good and Bad.

  1. With CENTER VENT OVEN, when the door is close and the vent outlet being hot, isn’t the cool air being drawn into it and thus cooling the dome?

  2. My dome is coming on. I’m interested in the centre vent. I was planning on hiding my oven under a rockery as it is buried in a bank. I would like to run the vent chimney back over the oven so it exits vertically on the far side. I’m hoping this will keep smoke off the patio. So long as I have an uphill run will this be OK? Should I put the chimney above or below the insulation blanket?

    I thought I may also create a connecting duct to the vent so i can place a wooden smoking box there to dry smoke fish and stuff.

    Any advice?

  3. is it possible to have the vent to the side of the door, about a quarter way around the dome…….it would require a separate door to open and close the vent, and a door to the opening….but do you see any problems with airflow if the vent is not part of the door opening? i planned poorly and poured my stand with the front corner cut off, then realized i don’t have room for the opening/vent….i do have room to the side for a vent though…..any advice is appreciated!
    thank you.

  4. we have a client that is going to buy a Modena2G140 Oven, could you advise as to the best way to extract /vent the oven, we are going to use twin wall flue duct, do we need spark protection.

    • Spark arrestors on direct vent applications are always a good idea. Our ovens are designed to have two methods of venting depending on local code. Direct Vent UL103HT chimney pipe or Type 1 Hood. If you are going direct vent (better heat performance as you are not drawing air out of the oven) then you want to limit any bends in the flue system to no more than 2 30 degree elbows. A straight shot is best.

  5. If I am building a gas fired oven. The air/gas mixture is made up outside the oven and the interior air is not needed inside the oven for the flame. Do I need a vent for this oven since there will be no wood smoke?

    • Always refer to the burner manufacturer specification and have a competent professional do your make up air calculations, but in general you will always need an exterior vent above the landing to allow the heat to dissipate and prevent positive pressure of the gas coming into the kitchen area. Many of our commercial ovens are used as gas only. You can refer to page 14 of our manual (we are in the process of re-writing this so the page number is only valid through August 2015).

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