There will be a blower that will kick on with a fan limit switch.
A wall thermostat will control the fan in the door and the dampner.
I had concerns about the secondary air and can plug that off if Im not liking the way things perform.
In my area, years ago there were several furnace manufactures, all were built the same way. 2 approx 6" pipes out of the firebox in the back, those 2 tubes went to the front of the furnace where they were joined to an approx 8" pipe that went to the back of the furnace and then to the chimney. Each had a cleanout door. I remember lots and lots of creosote,,, but that could have been that freshly cut oak block throwed in to make the fire last through the night. Most of these were connected to duct work, many are still in use today and alot of them are being used in shops with no duct work.
I just used 1 chimney pipe hoping for less to no creosote,,, plus my wood will be more cured,,,after I get ahead. Also this will only be used for heating my shop which is rather large with tall ceilings.
I currently heat with a waste oil furnace,, which works very nicely,, when it works. Its 5 winters old and is burnt out. Prices have doubled in the last 5 years = not in my budget.
Hardy OWB is huge in my area and the local dealer is a neighbor/customer but I just couldnt budget for this either.CB is starting to come in the area but I believe he is only selling the furnace, the install is not his thing. Earth and Shaver are kinda local, manufactor wise.
Right now I have less in the build than the small earth furnace,,,even counting buying a habor freight plasma cutter (which I highly recommend).
Once installed I'll list the good and bad of my design.