Arch Design Help

[Bob in Mo]

Newbie here start a design. If you would, take a look at the attachments. There are 2 arch designs. Please give me your opinions.
Thanks

[Les]

I would go with the shorter one. No need to make your reach longer than necessary.

[UtahBeehiver]

I agree too with the shorter one. Here's a pic of mine. I did add a decorative arch on the front too.

[jeeppiper]

One thing to think about is airflow and how smoke/soot comes out of the oven chamber itself. I cant say for sure, but my gut tells me that your hole/slot in your arch might be small.

I have watched my chimney and noticed that it "breathes" in-and-out depending on the wind conditions.

I designed in a "settling chamber" for the smoke to enter before it goes up and out the chimney. This settling chamber acts to provide a staging area for the smoke to gather before it gets pulled up the chimney. If there is no wind, it really doesnt matter. But if there is the slightest wind, then this chamber works great. Attached is a rough picture of what I am talking about.

There are many pictures of ovens on the FB website with soot on the front. Also, you dont want smoke or hot air exiting the front of your oven.

Just something to consider....

[Les]

Jeep - that is an interesting concept and I see where it would work. After a thousand more builds - these overs are going to be dialed in. The vent that Bob proposes is pretty much like what I have done, and yes, the wind WILL jack with the smoke.

[Mistertoy]

I made mine like your shorter version also. You might want to consider shaping the inside of the arch (see attached photos) like a few people have done so then your transition of bricks onto the arch is both easy and neat. I was glad that I read through the forums and saw how others had taken that approach. It takes a bit of setting up and cutting but I think it is worth the extra work.

Brett

[Laku]

Perhaps a short design for the entry but built similar to your first. Reason being the later design has a weak point in the vent chamber arch as it's not supported from both ends (see the picture).

This may or may not cause problems later on, but is a structural design flaw. As it's pretty easy to avoid I would not intentionally include that sort of flaw to the design.

[david s]

As I'm a fan of casting I would recommend casting the whole entry. That way you can make the entry even shallower and create compound curves easily so you end up with the entry funnelling to the flue pipe for efficient smoke removal. It also has the advantage, if you make the casting thinner than the bricks, of less thermal mass which makes it less of an energy robber. It is quite simple to create a damp sand mould and trowel the castable mix over it. No complex brick cutting required.

[Les]

Originally Posted by Laku

Reason being the later design has a weak point in the vent chamber arch as it's not supported from both ends (see the picture).

Laku,

I don't follow the "weak" issue. Many ovens have this approach (mine included ) and there is absolutely no problem - what am I missing?

[deejayoh]

Originally Posted by Les

Laku,

I don't follow the "weak" issue. Many ovens have this approach (mine included ) and there is absolutely no problem - what am I missing?

+1

Looks like an arch to me.