I bought this house this summer. It has two fireplaces, wood and what I thought was gas. In the top of the fire box where you would expect to see a sloping metal into the chimney there is a flat piece of galvanized steel with a round tube coming through that goes into the attic and turns and vents out of the back of the house. My first thought was this was a standard gas fire place just in need of logs. But after having it inspected the inspector was confused. I'm in GA and the best he can figure this is for some type of forced air heater??? His best suggestion was to insulate the top and cap it with a steel plate and install an unvented set of logs. I would much rather have a vented set, and wondered if anyone could tell me exactly what this might be, and if this was maybe added after the house was built in the late 80's. Could this be an addition to the chimney for an insert or stove, that could be removed? Take a look at the pics and let me know what you think. Obviously the tube is capped with cardboard and tape from the previous owner.