Indoor Pompeii WFO

[narcosis007]

Hi Folks,

Been thinking about building an oven for the past few years and came across your forum recently and have been absorbing your collective wisdom for the past couple of weeks. We are planning a kitchen extension and I thought it would be nice to incorporate a 90cm (internal) WF Pompeii inside the kitchen, probably in a corner.

Having searched this and other fora, I have found very little info on indoor ovens or the pros and cons of such an endeavour. Have any of you built one or researched the possibility? Would a well built and insulated Pompeii oven contribute significantly to the space heating of a 40 sq m room? Any advice, observations, comments greatly appreciated!

Thanks in advance,

Alan

[bookemdanno]

It'd be an absolutely wonderful thing to do, a great idea!

There may be a need to contact your local building control, for a little word and to let them know what you're thinking, as there's probably Regs that'll need to be incorporated. But i doubt that they're anything more than maybe a registered flue installer, or whatever is needed for a woodburning stove installation.
Some form of extractor fan may be needed within the flue.
They're installed within restaurants, so its just a case of following their lead i suppose.

Terry knows a few contacts who might be able to shed a bit more light, as they've probably built indoor ovens too.

[spinal]

I did look at an indoor oven, as I was planning a kitchen extension I was thinking of integrating it into the kitchen.

Sadly, once you look at putting it indoors, it falls under the "Clean Air Act" - which my area is part of... hence, I wouldn't be able to burn non-smokeless fuels (i.e. not wood); which made it a no-go for me.

M.

[narcosis007]

Thanks guys for the responses so far.

I must check the Irish "Clean Air Act", if such a thing exists, and see whether this would throw a spanner in the works. I'm assuming such an act would outlaw you from burning wood in a standard fireplace then too? Are there any other considerations I should be aware of in the planning of an indoor oven?

On a separate, but semi-related note, has anyone ever looked into fitting some kind of heat exchange circuit through the insulation layer surrounding the dome?

Cheers,

Alan

[spinal]

Unless said fireplace has an approved appliance built into it, or is tested as being exempt - that is my understanding. Something to do with smoke pollution and control... which is ironic, as I have tried to burn the so-called smokeless fuel, and it makes quite a bit more smoke than my oven when hot!

I would be looking at planning permission, building regulation/permission, and any smoke control rules. Flue angles and whatnot will almost certainly apply, but an experience chimney "fitter" (maker?) should be able to work with those.

As for a heat exchange circuit - that will defeat the point of the insulation You want to keep as much heat in your oven (and it's bricks) as possible, not channel it away to have a shower That said, I can see the purpose of having something to make use of the extra heat after you've had your pizzas... shouldn't be too hard to do either... a couple of copper pipes, a central heating pump and you should be good. (no, I haven't tried it, nor do I know what regulations that would need to go against)

M.

[bookemdanno]

Something within the flue might be a better option, or maybe you could rig up a layer of microbore copper, either around the outside of the bricks and under the hearth encapsulated within some mortar, but i'd think you'd need some sort of thermal solenoid valve too.
Like underfloor heating circuits in reverse, perhaps?
Getting the balance right of the copper far enough away from the heat source would be tricky too, so that you didn't end up with a steam engine would be difficult!
But like Spinal said, you'd possibly be slowing the heating up and speeding the cooling down, so if the trade off was one you were happy with to use the residual heat that way then go for it!
You'd be breaking new ground for a WFO, and therefore opening yourself up to the potential failures of prototyping, but it'd be really interesting!
I for one would be really enthralled by the challenge of it.

[spinal]

If you do go for it, please do post pictures and a build thread! I would actually consider re-building my chimney to put some water pipes in there if it works -t hat's how much I like the idea!

[faz]

The requirement for type approval and/or smokeless fuels only applies in a smoke control area.

With regards to heat recovery - you will find it very difficult not to get the water above 100 deg C, which will cause you problems even in a vented loop and could be explosive in a closed loop unless a suitable PRV is fitted.

Cooling the exhaust gases too much will cause excessive condensation of creosote and moisture in the flue which is also to be avoided - but there is certainly useful heat lost up the flue when the oven is being fired hard it would be a matter of getting the balance right so the flue gases remained hot enough at all times. You'd also need a way of dumping excess heat as once your hot water tank is at temperature your heating loop will still be absorbing heat from the flue or oven and it will need to go somewhere!

[narcosis007]

Some interesting ideas there alright, but like you say, controlling the heat in the circuit would be a real bugger. We currently have a back boiler on our living room fire which heats both our hot water and radiators. I like the idea of having any excess energy pumped into a heat store, but it does get complicated very quickly. In terms of the indoor vs outdoor oven, there's always the option of building the oven outdoors with access to the mouth from inside, through a gap in the wall. I like the idea of an open fire in the kitchen, and being able to cook in the oven in any weather. All food for thought at this stage, and I'll keep you lot updated when I eventually get started! Any other advice or ideas, just fire away!

Cheers,

Alan

[spinal]

Purely an idea - but what about a closed loop system with oil or something similar? That could power a radiator somewhere (and potentially that radiator could be immersed in a hot water tank?)

Just an idea... not sure if it's doable nor practical...

[bookemdanno]

I'd think that the outdoor oven accessed through a nice hole from indoors might be a way around it. Jamie Oliver has done the very same thing!

[pre0ats]

Like this....

www.thestonebakeovencompany.co.uk/news/beautiful-kitchens-magazine-bromilow-family-indoor-mezzo-oven/

Love the idea.

[narcosis007]

Now that's what I'm talking about! And a lot less disruptive to build the oven outdoors I'd imagine.

Does anyone have any idea what kind of heat loss(or gain to the room) you could expect through the oven mouth? I wonder would it contribute significantly to the space heating?

[stevo]

That looks quality. I'd imagine a drawback though, i can't build a perfect fire everytime so there is some degree of smoke coming out the mouth of the oven and having the mouth inside the house would make it look stars in your eyes... Unless you got some sort of mega extractor fan that would sook out anything that tried to escape out the front.

With regards to the heating, mine produces heat like nothing i've felt before - i've used it in the rain before and there was a dry half circle around the decking where the rain was evaporated before it hit. And i'd say if it was insulated enough then it wouldn't lose heat out when it's not on.

I'm not expert though, just a couple of things i've thought of.

Stevo

[narcosis007]

So would the chimney flue not extract the smoke preventing it from flooding the kitchen then, provided it had sufficient draw of course?