So I'll press my luck, I plan on calling a HVAC shop today, but wanted some ideas.
My addition is 480SF. Bedroom, bathroom, sitting room.
I do have a forced air pro-pain furnace, (never gets turned on though).
I heat entirely with a biofuel stove in the basement, and a high efficency wood fireplace, and woodstove on the ground floor. (I live in the woods) BUT
Its my understanding that I am required to install "mechanical heat" in the addition. What are my options.
Extend the existing furnace ductwork, supply and return, to the new addition, or add a small heating unit to the space. Chances are that the existing unit will not be large enough to handle the added load, so if you were relying on it for heat, the entire heating system would have to be zoned, or a larger furnace and ductwork installed.
The minimum is to add the ductwork, call the mechanical inspector and ask him/her if that would be acceptable.
I did have my furnace\AC checked for size by the mechanical contractor, they said it could handle the load of the addition. Of course they want the work, but I still have to decide whats best for the house.
My county Mechanical inspector is going to come out today and answer questions for me.
Running minimum ducts, is probably going to be what happens.