Last year I tore down my old drafty 100+ yr old house and built a new shop with an office/living quarters attached to the end in its place. The entire concrete floor has the radiant heat tubing already embedded, and currently I'm heating the office/living quarters with a Rinnai tankless propane fired water heater. My intentions from the start were to heat with an outside wood boiler, but rather than having it outside, I'd like to put it in the shop. I do have the room for it, and several days wood supply inside. I just run out of guts spending money due to the economic outlook, before I got the wood boiler bought. The pros as I see them are: 1) tending to the stove without having to go out in inclement weather, 2) wood won't be snow crusted or rain soaked, and 3) the expensive insulated piping bringing the hot water inside from the stove to the distribution manifolds will be eliminated. The cons: 1) expensive flue pipe through the attic / roof line, 2) discouraging words from insurance company about fire hazzards. I enjoy the smell of wood smoke and I've heated with wood stoves inside living rooms basically all my adult life, so I'm aware of the downsides to wood fired appliances inside and how to deal with them, and plan accordingly. The thing that I'm not sure of is the physics of changing from the short flue pipe that all outdoor boilers seem to have to a longer stove pipe/flue arrangement. I'm just hoping those short pipes aren't designed to allow a little downflow of fresh air for combustion, since a long pipe won't allow for that at all, period. Don't most of them have a fan forced draft into the firebox for adding fresh air for faster combustion? And if so, that wouldn't pose any problems inside the shop would it? Just wondering if anyone else has put an outside wood boiler -- inside? | 
outside wood boiler -- inside the shop
