Hello all, Im about to install a Heatilator Cab50 in my house. The placement will be on an interior wall, with vertical venting. I do have an exiting 6" wood stove stainless chimney in the house I will be using, it is 9ft in height from ceiling to above peak of house. The house is a one story ranch, can I get away with 3" venting from stove to ceiling or should I go with 4" at the cleanout Tee and vertical with a adapter at the ceiling. The manual states that one 90 elbow equals 3' of straigt pipe and more than 15' of venting to use 4". Thanks for the help, Brian. Im thinking 4" is what I need, just want to hear from the professionals and help this pellet rookie.