I know that no one cares what the maker says, but just for a complete picture I will include their instructions here, from pages 6-7 of something called "the owner's manual".
Emphasis is mine.
BEFORE LIGHTING
Blah, blah, blah...
D)
Open all vents on the bottom of the bowl.
SMOKING INSTRUCTIONS
Blah, blah, blah...
D) Pick up the lid by the handle, place it on top of the center section and
open the vent on the lid.
E) The vents are used to regulate heat within the smoker. Opening vents increases temperature and closing vents decreases temperature.
Temperature of 250*F is ideal for most meats. Check the temperature every 15 minutes and
open or close the bottom vents as needed until you achieve and maintain your target temperature.
Blah, blah, blah...
H) When smoking is completed, brush grates with a grill brush or crumpled aluminum foil to loosen any debris and
close all vents to extinguish the coals.
