I have a new Char Broil electric vertical smoker and have used it several times. After about two hours the smoke seems to dissipate or is not seen to be exhausting like before. Checking the chip box, the chips are all black. I think they need to be replaced at that point unless they just continue to give off vapors and appear to be done smoking. The manual says a full chip box should last six hours, but I only observe smoke exhausting for about two hours.
Would appreciate any input from you experienced smokers.