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-   -   Beaver Tail Oven anyone? (http://www.fornobravo.com/forum/f9/beaver-tail-oven-anyone-14918.html)

Lburou 12-09-2010 07:19 PM

Beaver Tail Oven anyone?
 
Has anyone here built a Beavertail oven?

I saw the Beavertail oven demonstration on MHA website documenting the Backyard Oven Workshop of 2006, has anyone built one of these?

Of particular interest is the picture of the gas cloud inside the oven. Has the corporate memory here seen one of these in action, and, do we have more modern designs that really handle the gasses any better than proven/old designs? Probably more work than I want to do to route the gases, but I'm interested :)

RTflorida 12-09-2010 09:38 PM

Re: Beaver Tail Oven anyone?
 
I viewed the MHA build AFTER having found FB and after building my Pompeii oven. Never really gave the MHA oven much thought until now. So I will ask the only questions that would matter to me.
1) Yes the photo looks cool, but does this gas issue REALLY matter? I have a straight up, from the entry arch, 4' Duravent chimney. I have nothing to compare it to, but have always been happy with my performance.
2) Is the MHA design truly based on function or is it merely for aesthetics? Again, my basic Pompeii burns completely white in about 45 - 50 minutes (great performance).

We all know insulation is the biggest key to success; I would not waste the extra effort and materials (put it into your insulation) on a beaver tail/squirrel tail oven unless I had a serious overhead clearance issue.....which probably would involve an install within a structure, then you are talking about national fire code compliance issues (limits the degree of angle and the number of bends in the flue).

The MHA is a pretty reputable organization, anyone know their reasoning for routing the gases? I've always thought (and read on this forum) that a straight shot flue provides the best draw, seems their idea is to constrict flow a bit (an attempt to burn unburned gases?). A trait you would certainly want in a heater for effiency, but why an oven?

RT

dmun 12-10-2010 07:11 AM

Re: Beaver Tail Oven anyone?
 
A note about all the ovens built at the MHA workshops: They are built with fireclay/sand mortar, and torn down the same week they're built. There's not much in the way of long term results.

As for squirrel tail ovens of all sorts: They are supposed to re-use flue heat to heat the top of the dome, but they work the other way too: if you plan to use your oven for any sort of retained heat cooking the squirrel tail acts as a big drafty uninsulated area right where you need insulation most.

Some low-dome Naples style pizza ovens use this sort of set up, but I've always suspected it's because of the aesthetic impact of a chimney that leaves the top of the dome.

fxpose 12-10-2010 10:18 AM

Re: Beaver Tail Oven anyone?
 
Quote:

Originally Posted by dmun (Post 103543)
Some low-dome Naples style pizza ovens use this sort of set up, but I've always suspected it's because of the aesthetic impact of a chimney that leaves the top of the dome.

I agree it has more to do with aesthetics than anything else, in the case with domes.

mn8tr 12-10-2010 10:27 AM

Re: Beaver Tail Oven anyone?
 
I remember viewing this before I started my build. The overall design did not do it for me. I am glad that I landed on the FB site for my WFO education. I was just a chisel stroke away from building a barrel vault until I read the information on the dome design found at this site.

shuboyje 12-10-2010 12:53 PM

Re: Beaver Tail Oven anyone?
 
I always thought the idea was using the flue gases to heat the dome, but my research has proven otherwise. According to what I've read the goal is actually to heat the flue from the oven, increasing draugh. They claim the oven will burn more fuel and not get as hot if the flue is to far forward.

GianniFocaccia 12-10-2010 01:15 PM

Re: Beaver Tail Oven anyone?
 
I don't understand the claim "your oven won't get as hot if the flue is too far forward' since heat exhaust loses it's heating capacity once it's left the oven, and realistically, how long does it take to heat up a flue anyway?

shuboyje 12-11-2010 05:57 PM

Re: Beaver Tail Oven anyone?
 
Again, from what I gather the claims are not that the heat from the flue gas is reused but instead that the dome heat in the vent increases the draugh and makes a more intense fire with more complete combustion. I agree the flue does not take long to get up to heat, but in my oven the hottest part of the vent maxes out at 700. The dome can get to 1200F+. Considering draugh is cause by temperature differential that difference of 500F+ could make a noticeable difference.

Lburou 02-04-2011 08:24 PM

Re: Beaver Tail Oven anyone?
 
Found a beaver tail oven documented on this site here.

dmun 02-05-2011 07:41 AM

Re: Beaver Tail Oven anyone?
 
Quote:

Found a beaver tail oven documented on this site here
I think that's just an offset chimney configuration, and it looks like there's insulation between the dome and the chimney path. It's a great oven, by the way. A true squirrel tail vents from the back of the cooking chamber, and channels the gasses up and over the dome, with some notion of reusing flue heat to heat the oven.

http://www.rumford.com/oven/images/ovenpa.jpg


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