Air inlet in oven floor?

[Hendrikwal]

Hi there, start building soon and was thinking to pul a 4 inch air pipe in the floor of my dome oven at the side where ill be burning my fire while cooking so i can get a good fire inside the oven and have my door closed so that i keep more heat inside the oven and i need less wood, i live in vietnam in a dry hot place whe there is nt so much wood around and i not want to put more damage to the local environment by using 2 hour of raging fire to cook my pizza on the weekend.
Any ideas about this?
I have not seen any plans that incorparate a air inlet so i not sure if its any good.
Thanks for the replys
Hendrik

[GianniFocaccia]

Re: Air inlet in oven floor?

The Pompeii oven design is the most efficient. Closing the door will cause the fire to extinguish, even with a small hole on the side. If acquiring wood is a challenge, build a smaller oven. If all you will be cooking is pizza, you can build your oven walls thinner than 4.5", which will take less wood/time to heat up.

[PsychDoc]

Re: Air inlet in oven floor?

The Pompeii may be the 'most efficient' in terms of retaining and reflecting heat but the concern here is efficiently burning wood.
Hendrik may still need to go smaller, but all the smoke that leaves an oven is fuel. Also a rocket stove uses small wood- like twigs. The rocket stove idea super heats the smoke so it too is burned.
I am in the early stages of a proof of concept and anyone who cares to may follow along. I may have success with a relatively new design, or provide a laugh when it fails, either way it should be instructive.
Roger
PS
I do not mean to contradict the experts, simply submit a different opinion.

[shuboyje]

Re: Air inlet in oven floor?

Roger,
You need to do a bit more reading and research before trying to reinvent the wheel.

A masonry black oven burns also burns the smoke after a little preheating. The only thing coming out of the stack is heat and water vapor. Obviously a rocket stove does this faster because it is built with minimum mass on purpose.

You are also far from the first person to try and incorporate a rocket stove into a masonry black oven. They all fail miserably. A rocket stove big enough to heat a pizza oven is just too big to fit in a functional pizza oven, they don't put out nearly enough heat. The only "successful" use is to use the rocket stove to preheat the oven before starting a conventional fire. This way you use the clean burning rocket to preheat the oven to a temperature where the conventional fire will burn cleanly.

I don't mean any of this to be discouraging, just want to point out that building an alternative type oven that can perform like a masonry black oven is a tall task. Lots of people jump in with both feet thinking it is going to be simple and thinking they must have a brilliant original idea when if fact it is something that has been tried and simply doesn't work. If you dig here and on other pizza sights you will find a wealth of information to save you lots of trial and error.

[PsychDoc]

Re: Air inlet in oven floor?

Thanks for the thoughts. I stand corrected on the smoke issue. I shall provide an example that others can laugh at and be entertained by. I hope my comments don't offend those who have gone before. My plan will be to make a cheap and dirty stove that can cook a pizza. The other question I hope to answer is if a clay pot will work as a dome.
As I review the original post, which I seem to be hijacking, the question is air in with door closed... So how to feed air while cooking so as to not extinguish the flame? The FB plans do say that a person shouldn't seal the oven with unturned fuel or it will burn violently when air is introduced, open door. Okay maybe not a direct quote.

So, to answer the original question... I suggest a damper in the door.

[Tscarborough]

Re: Air inlet in oven floor?

An efficient oven of any type is a discrete thermal mass insulated from the environment. The optimal oven design for a particular use or set of circumstances will be dictated by the indicated use of the oven expressed in the desired temperatures and the length at which they need to be held.

For a woodfired oven that will reach and maintain a temperature range in the 800-1000 degree Fahrenheit range while firing, and then carry heat through several days of cooking, the normal Pompeii plans are ideal. If you want to bake small amounts of bread, or large amounts of bread, or cook a couple of pizzas at 600 degrees, and be done with it, they are not optimal.

Delineate your use, then work from there to determine your thermal mass and your method of firing.

I have studied rocket ovens and they do not provide enough BTU's to cook Neapolitan pizza, period. If that is not your goal, then carry on.

[Hendrikwal]

Re: Air inlet in oven floor?

Thanks for all t info. I might just stick with a smaller oven to keep wood use down. I looked all over this site but could not find anything on air inlet inside the oven floor, im not talking about a build in rocket stove, im thinking just to build a normal wood fire inside the oven but on top of a hole thats suck air from outside directly to the fire, or maybe even put a small fan outside to push more air inside to get the fire burning while i keep my oven door closed.
That being said, the hole on the floor for air inlet use could also be used as a rocket stove chimney and the fan will also make the rocket stove burn better.
Its good to know that i cant bake oizza with this heat but at least i can at some more heat inside while baking some breads or stew.
Hendrik

[Tscarborough]

Re: Air inlet in oven floor?

For the type of oven you seem to want, look for a white oven.

Edit-the pneumatics of a Pompeii oven are surprisingly efficient.

[david s]

Re: Air inlet in oven floor?

A 4" hole in your oven floor could turn out to be a nuisance when cooking. Oops, where did that bread roll go? On the other hand it could also act as a convenient ash drop for cleaning. If you make the hole in the floor slightly tapered you could very easily cast a plug that could fit the hole. You could then have the option of firing and cooking in your oven in the normal way with the plug installed, or remove the plug and start the oven with the rocket stove for a smoke free start up then place the plug for some wood and real fire in the oven chamber for higher oven temps.
I think your idea has merit. I hope you go ahead and report back. Good luck.

[GianniFocaccia]

Re: Air inlet in oven floor?

or remove the plug and start the oven with the rocket stove for a smoke free start up then place the plug for some wood and real fire in the oven chamber for higher oven temps.

Couldn't the same result could be achieved with a thin metal blast door with vents at the bottom?

[david s]

Re: Air inlet in oven floor?

Oops, sorry Hendrik, I thought you were the guy wanting to install a rocket stove under your oven. Your plan may well work ok, try it and report back. The second two ovens I built, when I thought I was smarter than a couple of thousand years of WFO design, I built a port and terra cotta plug in the rear of the oven at the base of the dome wall. I did it so I could continue to fire with the door in place. Turned out I never really used it that way and now I just build ovens with the door as the only air inlet.