Aug 12, 2014 · How vents control temp. Most grills and smokers have two oxygen controls: 1) An intake damper that brings oxygen to the fire. 2) An exhaust damper (a.k.a. flue, vent, or chimney) that exhausts gases and pulls in oxygen through the intake dampers. The intake damper is near the charcoal or wood and its job is to provide them with oxygen.