I have an airtite stove w about 4 ft of 8 in. single wall pipe to my clay lined brick chimney. I have a damper installed very close to the chimney. I can regulate the stove much better with the damper/ airvalves than with air controls only. (much more heat output from stove). The hotter the fire, the more(faster) the air will enter the stove. Hotter stove/chimney =more draft. Cooler stove/chimney= less (slower) air movement throught the air controls. I put the damper close to the chimney to keep as much of the heated pipe in the room as possible. The pipe below the damper is much warmer than above. Maybe this works for me because my chimney is larger than my pipe(6x12) Even with my air controls almost closed down, as soon as I close down the damper half way, I can feel the heat output increase! Just my personal experience. Brad