Offset Entry

[robi]

Hello... I am in the planning stage of my second casted oven. The first is working great so I am going to build another at my beach house. Of course, there are a few lessons learned but one that I am just not sure about is having the entry centered. It seems like I could have more accessible usable space if I did something like this...



Have I drank too much IPA

Thanks for your thoughts...

Rob

[deejayoh]

Personally, I swap the sides for the fire and cooking, sometimes in the middle of a long pizza bake. It's a good way to recharge the floor. This design would make that more difficult. It seems like it would force you to cook mostly on the left, while making it a bit tougher to load the fire on the right.

[Petter]

I had the same though but for accessibility rather than space. After some thinking, I ended up trying to shorten the flue gallery and make it in a wide angle so it does not restrict any oven tools.

I still think it would work though but I did not dare to try.

[robi]

Thank you so much deejayoh and Petter for your response...

I thought the exact same as you both replied...

I should also mention how I use my oven... we have family pizza night on average twice a week, so far I would say we have had 30 pizza nights and I have needed to swap sides of the cooking floor 2 times early on due to me messing up the floor with a bad pizza load... max pizza's cooked in one night was 16. However, we use the oven almost daily for sourdough bread and/or dinner or cookies etc... fire all the way to the back and sometimes cooking close to the oven opening for less heat.

My thoughts are around accessibility and access... it also seems like I would have access to more useable floor space with the fire more to one side for pizza. My worries are thermodynamics... am I messing up how heat flows within the oven... maybe I am overthinking it... maybe just go with a wider opening.

Thank you for your thoughts and for reading my post...

I promise to better document my build this time... and share my experience...

Take care...
Rob

[MarkJerling]

Hello... I am in the planning stage of my second casted oven. The first is working great so I am going to build another at my beach house. Of course, there are a few lessons learned but one that I am just not sure about is having the entry centered. It seems like I could have more accessible usable space if I did something like this...

Have I drank too much IPA

Thanks for your thoughts...

Rob

Hi Rob
What do you mean by "more accessible usable space"?
Regards,
Mark

[fox]

I would think that an offset entrance like that ‘would’ have some effect on the air flow but, for better or worse I can not say.
Perhaps some form of circular air flow would form a ‘vortex’ or perhaps not!
A complex question that might need first hand experience to make any conclusion, you would have to let us know what happens!

[robi]

Hi Rob
What do you mean by "more accessible usable space"?
Regards,
Mark

I tried to write a reply but I think I can explain better by drawing, I hope you get the idea... thanks for making me answer that question...



Now Fox, you really got my mind spinning pun intended... we all know when the fire is in the back, heat goes to the top of the oven then out the front... fire on the side it rises to the top then over to the other side before escaping out the front... I really wonder what will happen with the offset... someone smarter than me has had to have already tried...

[MarkJerling]

I tried to write a reply but I think I can explain better by drawing, I hope you get the idea... thanks for making me answer that question...



Now Fox, you really got my mind spinning pun intended... we all know when the fire is in the back, heat goes to the top of the oven then out the front... fire on the side it rises to the top then over to the other side before escaping out the front... I really wonder what will happen with the offset... someone smarter than me has had to have already tried...

Aha! Thanks for explaining Rob.

I think your sketch is a bit of an optical illusion of extra space. If I sketch the same amount of "fire area" over your sketch then the resulting cooking areas are near identical. Plus, the time honoured ability to flip from cooking left to right to left etc to recharge the floor. I can't see any advantage in an offset entry.

[Ronstarch]

I definitely like the spirit of your post, and would be curious as to the results if you do go this route. My guess is: it will get hot, it will cook pizzas, it will cook bread!

By making the opening tangent to the wall of the dome as in your drawing, I do think you'd possibly set up some type of vortex/circular airflow pattern, like fox says above. Might be great for cooking bread, almost like a self-convecting oven?

As a side note, I just posted about my most recent cast build, in which I try to solve the accessibility problem another way, by eliminating the flue gallery (see in-process pic below). Although I've only used the oven a couple of times so far, it is much easier to maneuver around without that narrow tunnel in the way. I suspect the downside of my design is, I am probably losing more heat out the front of my oven, since a long flue gallery probably acts as a wind break. Since you say you use your oven for cooking bread all the time, this type of design might work against you, especially if you are currently cooking things IN the flue gallery, for lower temperatures.

I'm looking forward to seeing what you wind up doing!

[robi]

Sorry for the delayed response... I got sick and am now recovered... we'll leave it at that...

Very interesting design Ron... I like the idea of having easier access and maneuverability... I need a flue since the oven will be under a roof, the rain is too crazy here to leave it exposed... I also like to completely close the oven to trap the heat for the next day.

As for the offset entry, my heart and the experimenter in me tells me to go for it but something inside is telling me to not venture into the unknown... just finished the pad and stand so I have some time to think about it... My first oven works perfectly so I am hesitant to mess with what works...

[MarkJerling]

Good to hear you're better. Good luck with your build.

[robi]

Thanks Mark, and thanks again for helping me to reduce the complexity... if it ain't broke don't fix it...

[MarkJerling]

Too true! LOL
Thanks Robi.
Kind regards,
Mark

[Alomran]

I tried to write a reply but I think I can explain better by drawing, I hope you get the idea... thanks for making me answer that question...



Now Fox, you really got my mind spinning pun intended... we all know when the fire is in the back, heat goes to the top of the oven then out the front... fire on the side it rises to the top then over to the other side before escaping out the front... I really wonder what will happen with the offset... someone smarter than me has had to have already tried...

I would concentrate on analysing the heat currents within the dome.
The idea of having half a sphere with the entrance in the middle is to create a uniform distribution of heat throughout the oven.
If you create the entrance on one side, then one side of the dome will be hotter than the other due to the irregularity in the convection turbulence.This may cause the mortar and firebricks to expand and contract in an un-uniform way on either sides of the dome. It will cause imbalance in contraction and expansion of the dome on one side differently to the other. The uniformity is needed so that the contraction and expansion occurs in a uniform way so that the structure of the dome moves uniformly which means it remains stable during extraction and expansion. Expansion and contraction due to heat changes will crack the dome on one side more than the other which may cause imbalance in the structure. Imagine an egg and you assert an equal pressure uniformly on it... it will never crack, however if you do it on one side the egg will crack.