Next day temperatures?

[fox]

What temperature can your oven hold after 24 hours?
I realise ambient temperature & how long the fire was burring, quality of door etc will all make a difference but I just want an idea of what sort of temperature to expect after 12 ... 24 hours?

[SableSprings]

The real keys are mass and insulation (including an insulated door). Several builders in the forum have reported cooking temps for bread, roast, etc. several days after a pizza party. These ovens are well insulated and fully saturated with heat. The big bread ovens that Alan Scott designed/used had a very large mass and took a lot of wood and time to heat load...but they stayed "bread baking hot" for a long time with minimal small supplemental firings and without the improved insulation options we have today.

My oven is not well insulated but I've cooked a whole chicken the next day after a bread bake (I do my bread at 550-575F). I've attached a temperature graph of my oven that I did when I first started using the oven and again I know my oven is on the low end of the "heat retention scale" for most ovens here.

Since every oven is unique, it's important to actually do some temperature charting for your oven if you are planning on maximizing your baking opportunities & schedule.

[RandyJ]

Depending on what I was cooking and how long I fired the oven for i have had 24 hour temps in excess of 750F. Even in subzero temps it will take up to 10 days to fall below 100F. That is if the insulated door is in place. Last time I made steaks I had to leave the door off for several hours the second day so the oven was close to 500 to do a deep dish pizza. 24 hour after that I made some hot ham and cheese sandwiches and the temp was 450-475F. If you build it right and over insulate they stay hot for a really long time.

Randy

[fox]

Wow that is a well insulated oven!
I have only just finished drying my new oven, we got the floor upto 780f , the next day the floor was 350f but I don't have a door installed as yet.
I checked it this morning 36 hours after the fire went out and the floor was only just warm!
On reflectsion I wish I had used more floor insulation as I can feel the heat penetrating into the space under the plinth. I used 3.5" of vermiculite under 3" thick fire brick.
The dome itself has 4" of fire blanket and that seems to hold the heat back very well.
To be honest the oven may not be completely dried out yet........

[RandyJ]

I have 4 " of calsil under the oven and 3" of ceramic blanket over the oven then I filled the enclosure with 45 cf of vermiculite. I have never noticed a warm spot anywhere. My door is 4" of calsil warped in 22gage and 16gage steel. Works great with a tight fit. I also did so the recommended heat breaks.

Randy

[ziggyko]

What is Calsil?

[SableSprings]

Calsil is Calcium Silicate board (often referred to as ceramic board) used for high temperature insulation...perfect for wood fired ovens! Do a Google search for Calsil board and you should come up with quite a few threads on this forum that discuss the advantages of not only this rigid insulation board material (used for underneath the cooking floor) but the ceramic batting made for over the oven as well as other insulation options.

[UtahBeehiver]

If you are interested in building an oven, I suggest you get the Pompeii e-plans from Forno Bravo. They are a nominal cost, 3 bucks, and it will give you answers to most of your questions. It is a somewhat dated but is a good baseline of what is involved in building an oven.

[ziggyko]

Thank you for advice/info. I already purchased the plans. Now I am in process ordering /buying materials. (will start build in spring)
Does anybody knows supplier calcium silicate or ceramic fiber in NJ or other place with good price?

[UtahBeehiver]

Do a Google search for refractory suppliers. Most all will carry CaSi board. Distribution International is a source, located in Perth Amboy, NJ. I used them in Utah. Min. floor is 2", 4" is better, same with dome insulation except you use a blanket instead of rigid board. Good price? It will be expensive. If budgetary issues are a concern, you can look at perlite/vermeculite-concrete DIY mix. Just search the FB forum for thread links.