now that i know i can find pellets to run my pellet stove,i want to pipe it into my existing chimney.it used to be a fireplace that was filled in with concrete and has either a 6 or 8 inch round hole for the exhaust into the chimney.do they make adapters to do this?do i still need to keep a cleanout tee on the pipe?i cant put it on any walls,cause this house has way too many windows and i cant keep it away from a window for the piping