Hello,
I think this is not an good idea for the following reasons;
If you heat the empty space between the walls you also heat the outer wall = waist,
A RMH with 2 outlets (left and right)as on your drawing does not work very well / not enough draft
The amount of the surfacy you want to heat is far to much , i think one wall is about the max.
It is hard to clean out the waists in your design.
what I would do;
The starting chiney is an good idea but;
Only heat one wall
Put /locate the RMH in one corner
Build another thin third wall (in-between space about 5 cm.)in the room and let the hot air rise zig zag through it
You can make a thin wall by putting the bricks on their side
You can make a zig zag pattern in between these walls using thin tiles or bricks wich stick out and reach the other (second)wall when you are building it
It does not matter if they stick out in the room becouse it is extra surface /heat exchange
Make max. 4 zig zags . make sure the top of the wall is closed and let the hot air /smoke out only above the RMH using the same outlet as the starting chimney
Think also of a way for cleaning out the system when youre building it
Locate the exit chimney in the corner above the RMH
Rob Grip
Netherlands
