Barrel Vault with side door

[pre0ats]

Hi there,

I have been reading away at all the great info on this site, trying to decide between a barrel vault or dome design, but haven't seen anyone who has built, what I would think would be, a half-way house between the two - a barrel vault with the door arch in the side (i.e. into the barrel vault arch), rather than in the flat end.

This is the closest I could find: www.stovemaster.com/html_en/Semi_pre_cast_Brick_Ovens.html

Does anone have an opion as to why this isn't a design that is used more often?

[tonyb]

I don't see any reason why this design wouldn't work, there's nothing uniquely special about the dome/barrrel shape and wood fired cooking, despite what you might read. I think the main reason why barrels and domes have become the de faqto design is because they are relatively easy to build and are mechanically strong. There may be some firing issues as the size increases ie complicated air/exhaust paths but probably nothing to worry about on a small scale roughly square design.

[turkey]

the main reason for a barrel is extra space and usually thermal mass. Long and thin is easy to load. From the side it would be harder to fully utilize and I suspect harder to heat as you can't put the fire to the back as such as the chimney will be at the door and draw the gas/ heat to it, so it possibly won't heat the sides as easily unless you have a fire on each side.

these might only work out as marginal performance differences tho and unless its really wide I am sure you could manage it and clever design could change it. I don't want to put you off and just guessing as never seen an oven like it but those are my thoughts.

do you have specific space requirements forcing this design?

[pre0ats]

I can see that a squarer version of this design would be more akin to a dome than a long and thin barrel vault (i.e. if the fire was at the back then heat/smoke move up and down with the curve of the roof as it moved toward the entrance opening) .

But, to be honest, I'll probably stick with a conventional barrel vault design (or go modular) for ease of construction.

I just thought I'd ask the question given I had come across that design on the website I listed previously.

Thanks for the input/opinion.

[turkey]

the one on that site looks great, my opinions on it being less efficient where based on an oven say 3 times the width, anything closer to square or a little wider would work great.

I am not sure that oven from the link would be much harder to build, and it would look very cool. For most part preperation is key so time spent designing and extra effort making forms will pay off in better arches as well as a quicker build.

the end walls could be outside the arch so less critical on cutting the exact curve. Leave a few bricks in the arch sticking out sideways to tie the sides together with the arch.

[scottme]

The Stovemaster oven looks very good as far as the pictures go. I love the way they've used tapered firebricks to get a really tight looking exterior. But the outside of that oven they show being fired is going to get pretty damn hot. Surely in practice you'd want to cover it all in some rather substantial insulation layers to retain the heat? At that point I imagine you would lose some if not all of the aesthetic advantages of having the arch at 90º to a "conventional" barrel vault oven.

[tonyb]

One of the advantages of an extended barrel with side door(s?) would be to have different temperature zones for cooking, which is a limitation of conventional wfos.

[tonybut]

I am just starting my design and I have though to build a BVO that was wider than it is deep. Maybe 4 bricks deep and 1.2m wide.
This was provoked by my local pizza house where the fire in their wood fired oven is pushed to the side and the full depth used for cooking. If circulation of hot air is helped by the curve of the vault then I feel the heat source needs to be near the low edge of the vault not at the end?
Or is the position of the fire irrelevant because the cooking heat comes from the brickwork?

[cannyfradock]

Mmm...interesting comments on an interesting thread.

Preoats.......That's the first time I've seen a Barrel/vault oven with a door in the NON traditional place........no reason why it won't work, and I think it looks quite snazzy. The side walls should also be fire-brick though, in my opinion.

Tonybut.......everything is relevant in a Wood-fired oven build. The oven....regardless of commercial or domestic is usually taken beyond the temp needed, then the ashes are spread on the whole of the hearth, then pushed back to rear, left or right hand side of the oven. Once you have "heat mass" in the hearth ...and the dome, a small flickering fire is all that is needed to keep enough heat in the oven for many hours.

Would it be practicable to build an oven a lot wider than it's depth when the oven entrance can only be so wide before it loses too much heat to be used economically.....I don't know the answer.

Terry

[tonyb]

I don't necessarily think the position of the fire is irrelevant but within the context of other issues its not key. In a traditional barrel with fire at the back, the 'cold' air has to flow across the pizza before hitting the fire and then exhausting via the roof and back out the door. You could argue that this might affect the cooking of the pizza surface, but at cooking temp the air will get heated before it reaches the fire and the principle cooking method is radiation in any event.

[tonybut]

Thanks guys. Will start my own thread for my own oven, however....
The proposal for a side door also seems to tie in with my thought about circulation following the curve of the roof even better. A fire at the back leads the hot air to the door following the curve even in the heating process.
So are domes and vaults purely structural and could a completely square oven be just as effective? (assuming you could create a flat refractory ceiling)

[tonyb]

No, technically they aren't purely structural, though for amateur builders and cooks this is the over-riding benefit.

Most of the cooking, particularly in retained heat situations, results from thermal radiation, which as far as I am aware is a function of temperature and surface shape, a hemisphere give the most consistent radiation pattern. I doubt this makes much difference in practice in domestic situations.