I have a huge 39"x52" fireplace that I want to install a freestanding stove in. I want to use the chimney for a chase for the liner. Most of the stoves I see have the concentric vent connector. Is there a way vent with flex liner due to chimney not being straight and snorkel up 5' for fresh air and seal damper plate like when you install a insert? With a insert fresh air is not piped to the cap?