Al Smith
Mac Daddy
I did a little research on a rising column of hot air ,smoke in this case .It seems it rises in a circular fashion .As hard as this is to fathom with a square flue effectively the corners have little or no effect .It's as though in this case the 81 square inch area of the 9" square liner has the same effect were it a 9" round being 63 square inchs .
I further made reference compairing this insert which is a 1982 Lopi insert to a Lopi stove being made today . The later model has the same firebox area and a free standing type rather than a fireplace insert and it uses a 6" flue .6" would be approx 28 square inchs as oppossed the 38 sq inchs of a 7 inch . It should to be good to go--or I'll be pissed after doing all that work .Cornfield rocket science 101 .
I further made reference compairing this insert which is a 1982 Lopi insert to a Lopi stove being made today . The later model has the same firebox area and a free standing type rather than a fireplace insert and it uses a 6" flue .6" would be approx 28 square inchs as oppossed the 38 sq inchs of a 7 inch . It should to be good to go--or I'll be pissed after doing all that work .Cornfield rocket science 101 .