Originally Posted by
BillyBob58
If it was going to happen to anybody, it should have happened to KWPAPKE at minus 23F.
Not necessarily. As the temps get well below freezing, there is no problem with puddling because the water freezes to form frost.
I have never had a problem with water condensation in the SS/SB, but my experience may differ from some others due to the conditions:
- At colder temps the air in Minnesota is pretty dry
- Most of my very cold temperature use I augmented the OCF pad with an Exped Multimat
- I use a mummy bag, not a quilt
- I use the Overcover when the temps are below freezing, which would tend to keep more moisture in the hammock
You can see pictures of the frost formed on top of the Multimat in my BGT report:
http://www.backpackgeartest.org/revi.../#Field_Report
The Multimat adds a 2nd VB, as it is a foam mat with a silnylon cover on one side. In this case the frost is forming between 2 VB's. In theory, there should be no moisture from the sleeper migrating down through the SB, and no exterior moisture migrating up through the Multimat, but I'd get frost forming anyway.
Back on the first page of this thread MacEntyre stated:
Cool outside air warms up when it leaks inside the insulation, below the SB. It can then hold more humidity, which it takes from the cooler air outside via the leak. The sleeper moves, a charge of cold air leaks into the insulation, cooling the previously warmed air, which condenses. Leak cycles again, making more condensation. Sleeper awakens, finds water in insulation below SB, but none above. Sleeper is puzzled.
He may very well be right. There is very likely a pumping of air in and out of the SS as the sleeper tosses and turns.
Of course none of this is an issue to me these days as I've moved to Tucson where the air is incredibly dry and warm. 
--Kurt
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