I have been smoking salmon for many years and learned how to cold smoke from a native family here in alaska!
here is the recipie that I was taught many years ago...
cut salmon fillets in strips lengthwise from head to tail about 1/2 to 3/4 inches wide
make a brine with water and enough salt to float a potato. brine for 8-10 minutes (yes that is minutes not hours)
hang in smoke shack tieing two strips together and hang over sticks.
run an alder fire all day and all night for the first 3 days until outside of fish is "sealed"
run an alder fire once per day for 7-10 days until salmon is dried to desired level.
keep in mind that the smoke shack was exactly that... a shack about 6 foot wide and 8 ft long about 8 ft high. built very much like a bad garden shed. framed out 2x2's and covered with rough cut 1x6 with lots of "holes". what i am getting at is that it was in no way "sealed up tight" from outside air or anything else!
the product was a dried "sqaw candy" type salmon sticks. I have used this as a recipie to work from and smoked salmon in a "little chief" for many years. I would brine it as listed above (I added some spices and stuff to the brine) and would smoke the fillet chunks flat(not hanging) in the chief for about 7-10 hours depending out outside temp and wether it was raining or not. I have never had any problem with this product and have been eating it for many years. keep in mind that the little chief does not maintain a consistant temp so it is hard to say what the actuall smoking temp is. I have since moved on to a different smoking method. (new traeger)
please keep in mind that I am not qualified to give food advice as I am not a trained or liscensed food professional but this is just my experience!!