It is open during the cook but I like to close everything up when not in use and the ball valve makes that easy. Don't want small critters getting in my smoker and keeps the moisture out.
my avatar swiped fatties from the plate....look how sorry he is.
NB Bandera with mods
Weber 22 .5" x 2, 26.75" x 1
UDS x 3
Created "The Great Spam Revelation of 2011."