Having problems heating up a larger oven

[joempdx2]

Just spent a bunch of time and money building a 48" diameter oven with a 21" high dome and having some problems getting the oven floor hot enough to cook. Maybe it is just because it is bigger, but built a pretty good fire and let it burn for an hour an a half. I don't have a thermometer, but it seems like all the heat is in the dome and not much on the oven floor. I built the fire in the front and then pushed it to the back when it got going good. Anyone have any ideas...much appreciated.

[james]

Re: Having problems heating up a larger oven

Hey Joe,

I have moved this to Oven Firing. I think you will get more input here. In general, Italian brick ovens can scale up to 72" and hold pizza-baking temperatures on the cooking floor.

My Artigiano120 is 48" deep. It does take a little long to fire than a smaller oven, but it definitely gets there! :-)

My guess is that you haven't had either enough fires or large enough first to fully heat the oven. Also, what type of insulation do you have under the cooking floor.

Let us know how it goes.
James

[Jed]

Re: Having problems heating up a larger oven

Hi Joe,

I will have to work a bit to get my oven hot also... It's a 36", but I have not been able to get a fire that will heat the oven in less than two hours. I read some guys are able to get by with a fire in the oven for an hour and a half, but what ever the details are with my situation, I need more time.

It could be that the wood I have access to is Pine. A hard wood might do a better job of producing a hotter fire. And it could be that I don't build the fire hot enough in this oven... Or my insulation installation may be marginal, and the structure is pulling heat away from the fire brick. I don't know the cause, but if I want my oven hot, I need to plan on more than two hours of firing.

As the fire burns, you will see the soot on the top of the oven dome eventually cook off, and 'turn the oven dome white' - this is the clue the oven brick are getting saturated with heat. And then it takes a bit more time for the full dome to get hot enough to 'turn white'.

What side of the State are you living - east or west? We are in Bend, if you get this way, give a shout and we can trade oven stories!

JED

[james]

Re: Having problems heating up a larger oven

If you want to bake pizzas, and not completely fill your oven with heat for baking later, you should definitely be able to fire your oven in less than an hour. The rush time for the Casa90 is about 40 minutes, the Primavera is about 30 minutes and there are Pompeii Oven owners who can easily beat the 60 minute mark.

Do you think it is the pine that isn't driving enough heat into the oven? Two hours is pretty long.
James

[Jed]

Re: Having problems heating up a larger oven

Do you think it is the pine that isn't driving enough heat into the oven? Two hours is pretty long.
James

Hi James,

I'm not sure...

It is most likely that I just don't get the fire hot enough fast enough. It might be the wood...

I guess more experimenting is in order!

JED

[Frances]

Re: Having problems heating up a larger oven

Just spent a bunch of time and money building a 48" diameter oven with a 21" high dome and having some problems getting the oven floor hot enough to cook. Maybe it is just because it is bigger, but built a pretty good fire and let it burn for an hour an a half. I don't have a thermometer, but it seems like all the heat is in the dome and not much on the oven floor. I built the fire in the front and then pushed it to the back when it got going good. Anyone have any ideas...much appreciated.

What James said.

It sounds to me as if your fire wasn't near big enough. It doesn't need a pretty good fire, it needs an enormous fire. Your oven may also not yet be entirely cured, it takes a couple of really big fires for everything to come together properly. My guess its that for the next 4 or 5 fires you will need a lot of wood and a lot of time to get your oven up to heat, but that heat up times should get shorter afterwards.

[nissanneill]

Re: Having problems heating up a larger oven

I go through a builders wheelbarrow of split redgum (eucalyptus hardwood) in around 1 1/2 to 2 hours with a large spread out fire to get my 40" Pompeii up to 500˚C+.
You will need to use more wood and have pretty serious fires to generate considerable coals which you then spread around your floor to get some real heat into the hearth.
Does your dome outer surface get warm or hot at all?
What about the bottom of your hearth slab, is that cold after your fire?
If either are hot, the you are loosing too much heat and need more insulation!

Neill

[christo]

Re: Having problems heating up a larger oven

I'll Chime in here.

I don't use all that much wood in mine, but it could be the wood I use - fairly large chunks of hickory that has dried over a year. I bet I burn two armloads of wood per pizza night - that's it.

I also used DMUN's oven design so my oven dome does not carry as much mass as a normal Pompei - but I bet its similar to some of the FB ovens as my 39" can heat up in 45 mins if I make a really big (but not scary big) fire....

My times for a normal fire (fire on one side of the oven with flames licking the ceiling and travelling all the way to the other side of the oven) is about 60 mins. Maybe my normal is closer to big scary? Big scary to me is like that time I filled the entire oven with wood for coking too early and the entire oven load of wood burst into flames - fire everywhere!!!!

Christo

[lenneest]

Re: Having problems heating up a larger oven

Thanks for all the input. I have been able to get it up to speed. I like the pizza, but want to get more bottom heat and am playing around with that.