I added a 400 sq. ft. addition (family room and larger kitchen) to my tri-level house, which my oil furnace and central air do not adequately heat and cool. My oil and electric bill is about $500 every month (annual budget plans for both). Rather than replace my 9 yr old oil furnace and ductwork, I believe a pellet stove is a viable heating solution. I have a brick fireplace in my living room (front of house), and sandwiched between the average sized LR and the new family room in the rear of my house is an averaged sized dining room. There is no wall separating the LR and DR, and there is a supporting wall which is almost completely open between the DR and FR. So my LR, DR and FR and all basically open. The FR addition has a cathedral ceiling. I WOULD LIKE TO KNOW WHETHER TO INSTALL A PELLET FIREPLACE INSERT IN THE LR, OR INSTALL A PELLET STOVE IN THE FAMILY ROOM ADDITION. Will a pellet stove in the FR make that room very hot? Will a pellet insert (high efficiency) in the LR fireplace adequately heat the FR addition in accordance with the room layout I stated above? I will probably install an auxillary AC unit to cool the addition, but any suggestions about the AC are welcome. TIA (Thanks In Advance).