Chimeny, chim chim cher-oo

[Bill Cornett]

I was planning on a clay flue but i have an opening about 21" x 3.5". Should I close this down and use a clay flue or insulated flue pipe with a rectangular reducer? I will have a brick or concrete board enclosure with stone on the outside of chimney.

[Bill Cornett]

when I look at the gallery I see some of the ovens that look like the door when in place will be on the fire side of the vent and some that look like the door is on the other side. which should it be?

[Bill Cornett]

remeasured opening. it is 18" x 4"

[chidding]

For those of us who want to bake with residual heat, its best ot have the door blocking all airflow .. as you desribed.. "on the fire side".. otherwise the flue will suck out all the heat.

Chimney design is really a personal taste, i opted for a custom stainless spigot .. square base and round fitting.. look at some builds.. its all personal taste.

[Bill Cornett]

Since I am not willing to tear out the chimney and entry, I think I am going to try a deep door to block most of the heat loss. Do over moment...chimney about 8" toward the front. My hindsight is AWESOME!

[GianniFocaccia]

I think I am going to try a deep door to block most of the heat loss

Bill,

I think you want to block ALL of the heat loss. Try to configure a door that fits snugly against the reveal and behind the flue. An 18"x4" vent opening should be easily amended into a flue gallery that will accomodate a clay flue pipe, IMO.
John

[Bill Cornett]

what do you mean a "flue gallery"?

[GianniFocaccia]

I understand a flue gallery to be the geometrically-shaped void that begins with the vent and funnels oven exhaust upwards directly and terminates with the flue pipe.

[RCP]

How tall do you suggest?

[Bill Cornett]

Llast night I set a new 9"x9" flue liner on top of my short chimney. It was not mortared or bricked in. I cooked 5-6 pizzas and noticed the flue liner had a long 24" vertical crack. There were many other smaller cracks either horizontal or diagonal. The people at the supplier thought it was strange but were not alarmed. One did say in a house it would be a no-no but outside in your oven...
I decided to keep it. I am in the process of using clay multi holed bricks to form up a surround with about 2" between it and the liner. I am going to use a 10:1 or 12:1 vermicrete in the gap. Then I will continue my steel stud enclosure and stone it. Using regular mortar on the clays since there is a gap which will be insulated. I did set the liner in refractory mortar and put 2 fire bricks on either side also in the ref mortar.