Know Bull - I never open the door so heat BTU's getting out that way. I bought it so I could sleep and I have been sawing some logs
Weardc - I like your smoke adapter I have thought about adding something small like that. There is room in the firebox for it, the firebox is on the back of the 120 where I think it is on the bottom of the 100. I could add a few chunks of wood for the first few hours, then go to bed.