Underquilt Protector Trapping Moisture

[SteveE]

Maybe it was the unusual climb in temps last night and the fact that my UQ set (layered) was WAY to warm for the conditions..I didn't wake up feeling overly hot or sweaty but maybe I was....

[BillyBob58]

I purchased one years ago, used it once, and had the same thing. I bet I had more dampness than you experienced. I sold it after this because I didn't want to take chances. It was the breathable version. Lots of people like them, but it's not for me. I want that body vapor OUT as easily as possible. That is critical as the temps drop.

It would be like wearing fleece and wool in the winter, but then putting a "breathable" rain jacket over the top of that. Ask any true northern winter camper if that's a good idea.

Of course, the problem is that moisture does not always exit the quilts. In this case, adding the UQP moves the dew point outside the UQ's shell, to the cold UQP. But who can say that vapor does not reach the dew point inside the UQ shell- in the down where it is absorbed and maybe not noticed at first? In fact, such does happen, I have seen it happen with friends, where it was enough to notice after about a week. IOW, if the breathable UQP does not keep condensation from happening, I'm not sure my UQ's breathable shells can keep it from happening either. But, if it happens inside in the down or CS, I probably won't notice it at first unless I weigh the quilts.

But I never have these issues, at least not when I use the space blanket right under the hammock and inside all of the insulation, even if I have a total VB on the outside layer, totally water proof. Or, if I wear VB clothing, like kwpapke did on his minus 26F HHSS adventure with Shug. But I realize I am in the severe minority with these views. But, for every one, HYOH!

[BillyBob58]

I guess that's why it's good to practice this stuff in the backyard eh? I may try again tonight with a looser attachment (thanks Shug) as mine was set up pretty tight. But I tend to agree that I can't risk getting them wet while on an interior winter trip or late fall canoe trip...

Loose is better. Perfect is a slight space between the quilt and UQP, in case condensation does occur on that outer most, coldest layer, rather than inside the coldest layer when no UQP is used: your quilts outer shell. (assuming you are not using any VB on the warm inside to keep that moisture from ever reaching either the quilts down or shell or the UQP so that it can condense when it reaches the dew point)

[BillyBob58]

Has anyone here ever slept out under the stars, under very dry, low humidity conditions, and woke up to find frost on the shell of your quilt or bag, but no frost anywhere else? That is condensation of your body vapor when it hits that cold shell. I seriously doubt that the frost is always ONLY outside that last millimeter of breathable shell, and that none of that condensation occurs on the inside of the mm. The colder it is, the further into the down the dewpoint goes. The thicker the down, the further that outer layer of down is to from your warm body, warmth that is keeping it from reaching the dew point. Just food for thought!