Larger inside diameter

[Michaelspizza]

Hi,
I was wondering if I chose to build my oven with a 48" inside diameter instead of 42", would I be running afoul of something in regards to thermal mass, i.e., would it take substantially longer to heat?.....would I lose more heat more quickly?, etc. A 48" sphere is about 50% larger in volume than a 42" sphere. Thanks, in advance, for your input.
Michael

[david s]

No, because the chamber volume is much bigger then the fire can be bigger. The larger volume means a greater fuel consumption, but it should be more efficient, Assuming the wall thickness is the same then heat up may be quicker. You won't be firing it up to only cook two pizzas though. You better have a good supply of free wood.

[UtahBeehiver]

Michael,

A 48" oven is a really big oven. So you need to ask yourself what are you going to cook? Most of us do not cook more than 2-3 pizzas at a time and a 32"- 42" oven can handle that easily. Are you going to do breads, Again most of the 32"-42' ovens can handle more that most people need or want to cook or bake at one time. A 48" oven will take more fuel, Can't comment on heat times but mine is a 42" and it takes about 2 hours to reach white dome. Karangi Dude did a 48" oven but he also taught wood fire cooking classes. Loss of heat is relative to how well the oven is insulated. More is better (up to a point). Do a search on larger ovens, although not prevalent there are a few out here on the forum

[Michaelspizza]

Thanks, guys.....nothing is cast in stone (no pun intended)...as I am first "building" this in AutoCAD in 3D brick by brick....actually plan to use the insulating concrete form, NOTBLOX (i manufacture these), to make the stand....take a look at the website....www.notblox.com....and thanks, again. Will keep you informed of my progress....you may not hear much for a while because the oven is part of a full renovation/restoration of a 100-year old "Charleston Single" home in Charleston, SC so I will be working on the pizza oven as I get bored with the other construction. Stay tuned.

[david s]

Hi Michael,
I'm interested in your insulating blocks and wondered what material you use for thr insulating aggregate?

[Michaelspizza]

david s .......Not sure what you mean by the insulating aggregate....are you speaking of the NOTBLOX material itself or the materials in some portion of the pizza oven I will be building?

[Michaelspizza]

I had a question about door opening dimensions....the only thing I have found online is a reference to the width of the opening being 0.6 times the inside diameter....well, if I go with a 48" inside diameter , that would put the opening width at about 28-29 inches. This seems a bit large to me insofar as placing pizzas or cookware inside the oven but then again for cleaning out the ashes, it might be a wise choice. Does anyone have a "rule of thumb" here and, while you are at it, please opine also on the height.....and if you REALLY would like to opine, I am open to hearing views on the arc of the arch for the opening....plan to use brick arches instead of lintels.

[RandyJ]

I would suggest you talk to Gulf. I think he has a larger oven. So he would be a good person to talk to.

Randy

[david s]

david s .......Not sure what you mean by the insulating aggregate....are you speaking of the NOTBLOX material itself or the materials in some portion of the pizza oven I will be building?

Yes, I was looking at your product Notblox and wondered what you use for the insulating aggregate in the mix.

[david s]

I had a question about door opening dimensions....the only thing I have found online is a reference to the width of the opening being 0.6 times the inside diameter....well, if I go with a 48" inside diameter , that would put the opening width at about 28-29 inches. This seems a bit large to me insofar as placing pizzas or cookware inside the oven but then again for cleaning out the ashes, it might be a wise choice. Does anyone have a "rule of thumb" here and, while you are at it,
please opine also on the height.....and if you REALLY would like to opine, I am open to hearing views on the arc of the arch for the opening....plan to use brick arches instead of lintels.

Forget the 0.6 rule. As you point out for a large oven it makes the opening too wide. For a small oven it would make the opening not wide enough. Just go with what you think will give you a wide enough working space. The bigger the mouth the greater the heat loss. The smaller the mouth the smaller the heat loss, but the more difficult it is to work the oven. The height of the mouth should be 63% of internal height give or take an inch or two either way.

[Michaelspizza]

david s....thanks for all the input. Did you really mean "The height of the mouth should be 63% of internal diam..."?? sThat would put the door height at 30"....you meant to say 63% of RADIUS?.... or internal dome height??....

As to the NOTBLOX, the material is generically known as wood concrete....been around for a long time...basically the same as regular concrete except aggregate is a coated wood chip.....the coating precludes any leaching of organic sugars if you choose to use green wood...we use seasoned wood but coat it anyway....amazingly, this stuff will not burn, termites hate it and it breathes so you cannot grow mold or mildew on it. Bonus is you can screw into this material anywhere on the form.

[UtahBeehiver]

I am pretty sure he meant radius or internal dome height not diameter.

[david s]

david s....thanks for all the input. Did you really mean "The height of the mouth should be 63% of internal diam..."?? sThat would put the door height at 30"....you meant to say 63% of RADIUS?.... or internal dome height??....

As to the NOTBLOX, the material is generically known as wood concrete....been around for a long time...basically the same as regular concrete except aggregate is a coated wood chip.....the coating precludes any leaching of organic sugars if you choose to use green wood...we use seasoned wood but coat it anyway....amazingly, this stuff will not burn, termites hate it and it breathes so you cannot grow mold or mildew on it. Bonus is you can screw into this material anywhere on the form.

Thanks, that's interesting stuff. My apologies, I meant 63% of internal height.

[Michaelspizza]

NEW QUESTION! So, we have begun construction....have base slab poured and will begin wall construction to support hearth later this week....have decided to go with 48" oven....thanks so much everyone for your help to date...so here is my new question....thermo-couples...do I want to install them and is there a good place to go to read up on these? Read a couple of forums/blogs....one guy had 6 or 8 of them....seems a bit over the top for me but 2 seems about right....maybe 3....one in center of floor, one at outer perimeter of floor and one at the top of the dome....yes? no?....what I am looking for is the best way to install them and what to hook them to....the guy with 6 or 8 of them had a hand held digital meter to which he plugged the thermo-couple wires....I am too lazy for this....would it not make more sense to have a permanent display of gauges....one for each thermo-couple....installed/integrated into the structure somewhere? Or is this all much ado about nothing and I should just install a thermometer in the door of the oven and let that suffice.....or should I do that in addition to the thermo-couples.....???

So there you have it...rather long question...thanks in advance for your help.

[UtahBeehiver]

What are you planning on cooking with the oven. If breads, TCs could be valuable for temperature and brick saturation. I have two TCs opposite of where I place the coals, one neat the interior of the brick and one near the exterior of the brick. However, I rarely use them know, once you have fire the oven a number of times you get the know it pretty well. I use a thermo gun for ball park numbers. However, I have not started baking bread in earnest yet so maybe the TCs will come in handy. So up to you. Can't comment of thermometer in door since I do not have one there but there are mix reviews on the forum.