Granted, I've not burned that much; but this is my first wood stove and I wanted to see how the stove is burning. Y'all know, just to gauge things. I got essentially nothing (less than1 tablespoon) out of my chimney I'm burning 2+ year old maple and ash now. My 13NC has 5ft. of doublewall stove pipe with offset back to back 45's out of the stove to the ceiling support, connected to 11ft. of class A chimney. I'm happy.