Jerry VanLuvanee

2 stories with full attic.

Hope this simple drawing helps.  I could create an 8' long bench off to the right for more thermal mass.
A concern is that the high Temps will affect the lime mortar of the fireplace. So I would need to coat the stone work with ??? material to slow the heat absorption I'm thinking.

The fireplace is an interior wall, the room dimensions are roughly 21'x24' A kitchen addition was built on the other side of it that wall.
She really wants a cob bench, so I'm just going to have to move some stones.
The bread oven is just an idea, I think I have a lot of space to utilize.

My hydronic system is about as good as it can get, trv's on each radiator, constant circulation, etc.  I've done a lot of researching and talking to others on storing heated water, and the consensus is to leave the heat energy in to coal.

What material should be used to create the heater?  Can a bread/pizza oven be incorporated into it?

16"-18" stone walls in the process of repointing with
natural lime morter, no insulation.
Fireplace alcove is on the 1st floor.  I poured a concrete hearth the 1st year we were here, and the fireplace foundation goes down to the basement and is massive.
6" stainless flexible pipe up the old stone chimney, interior of the house.  Measured from the hearth, it's around 27' to the chimney cap, so maybe the chimney is around 21' long.

That's an interesting design, I'll definitely have to look into it some more.
I don't really have an idea what would work best. I loved having a roaring fire in the blaze king, but could never get enough heat out of it.  She loves the cob benches of a RMH but I dont really have any way of doing that unless I make a hole in the stone wall.
I am currently heating cast iron radiators with a coal boiler, it does a great job of heating the house. But if the power goes out, there goes my heat.
I would love to incorporate some piping to circulate water to my radiators as well, if possible.

So my wife is a member, but I thought I would join as well.  

I have an old stone farmhouse (late 1700's early 1800's).  We had a blaze king princess free standing stove, but let's just say I was underwhelmed by its performance as well as the fragility of the catalytic combuster.

Ive got a fireplace alcove to use.  It roughly measures 51"Hx51"Wx30"D.
I was going to have a custom wood stove fabbed up to fit in the opening. (w/glass doors, I like watching the fire)
But my wife wants a rocket mass heater.
I've been trying to think up some combination.  I would like the stone walls of the fireplace to act as the mass.

Thoughts, ideas, plans are welcome