I pat my jerky as dry as I can with a paper towel before adding it, smoke at 145-150 for the whole time, and then do not turn the dryer on for two hours. You can if you want to use the dryer to dry the jerky for a bit without heat or smoke to get a little pellicle forming before you start with the smoking phase. Same would hold true for your salmon I would think. Although, I think your pellicle may form better by sitting in the fridge uncovered, but I am not a salmon smoking expert. I generally just let the jerky sit on my counter spread out with a fan pointing at it for an hour or two before putting it in the smoker.
You don't want the fan on during the smoking phase as all of the extra oxygen that will get pumped in will likely cause your 1.5-2.0 ounces of wood chips (chunks may have trouble smoking at these lower temps) to combust and start burning instead of smoking which is NOT what you want.