Originally Posted by
mopheadrob
Just to clarify, I don’t think it will be moisture from the outside air, as this would only condense on cooler surfaces (think beer cans). What’s happening is interstitial condensation, similar to what happens in the walls of a house.
Air heated by your body gets drawn to the outside, taking vapour with it. As it contacts the outside it cools and can’t hold as much water, so it dumps it. Look up ‘relative humidity’.
If you’ve got condensation on the outside then the bag is doing it’s job, and not allowing it to wick back into the absorbent filling. More of a worry if the condensation occurs on the inside of the outer shell.
You should dry it as early as possible though, DWR coatings can only do so much. If you must pack it up damp, then take it out as soon as you set up your next camp.