I ended up closing up the vent hole. That was enough of a draft to allow the wood chunks to burn, (note 55* rise in temp) with the damper shut. I put some good ole grey tape over the hole and plan to stop it up later. The smoker is pretty air tight as I have a seal around the door. I am going to drill a hole into the side and place a piece of hose thru it for conduit and run me thermometers thru the hose. I will then seal that hose with some high temp silicon. Sorry to ramble, but yes, I think I have enough leakage without the hole. I can see if it were gas fired the hole would be necessary for a clean burn.