Vent

• The vent is a key component of the smoker, in that it controls how much smoke is pulled out of the unit. The draft created by the vent will allow a certain amount of smoke out depending on how the vent is adjusted. Since even the driest wood still contains some amount of moisture, excess smoke buildup can create condensation as the moisture is sucked out. This condensation, if not allowed to properly vent, will build up on the chimney of the smoker and create unwanted levels of moisture. Adjust the vent as the smoker works in order to find the right level. You want to let enough smoke out to make sure the moisture level remains even, but not so much that the smoker completely empties and stops cooking the meat.
  
  

Water pan

• Smokers often employ a water pan to help add moisture during the cooking process. As water evaporates, it creates humidity around the food and produces much more tender meat. This is a great way to add moisture, but you can also manipulate the water pan to reduce moisture. This will allow you to produce a drier, more seared effect on meat--such as a thick crust on BBQ ribs. To do this, instead of putting water in the pan fill it with rocks and place it inside the smoker. This will suck up moisture as the rocks heat up, producing a much drier environment than even extra venting could provide, without the smoke loss.
  
  

Smoker quality

• An often overlooked factor in the moisture control of a smoker is the construction of the smoker itself. The moisture inside is a direct result of condensation that builds up along the walls. A cheaply made smoker will have thin walls made of cheaper material, and condensation will be less likely to build up and remain within the cooking chamber. This will create an under-moisturized environment. To ensure proper moisture control with minimal manipulation from you during cooking, be sure to purchase a decent quality smoker that makes note on the packaging of thick-walled moisture-retaining material.