I am looking at doing a 6 night backpacking/snowshoeing trip this January to the Pecos Wilderness of Northern NM. When I did this trip last year I noticed that I lost some loft, though not a significant amount, on my down bag due to condensation from perspiring while sleeping. Because I move camp everyday and am traveling slowly thru deep snow I usually don't have time to hang my bag up to dry out at the beginning or end of the day, so any condensation that forms in the bag stays there and gets added to every night. To avoid that this year I am strongly looking at using some sort of vapor barrier to limit the moisture build up in my bag. I am leaning towards using VB clothing over a VB sleeping bag liner because the clothing allows me to layer insulating layers on top if needed (I use a 15F bag for most of my winter mountain travel). I wanted to see if anyone out there had any experience using VB clothing for sleeping, and wanted to see if anyone had any suggestions on whether I should look at taking a shirt and pants or if I can get by with just a shirt. Thanks for you suggestions.

I don't know about you but when I sleep and perspire; one of the number one spots is my feet. I'd consider some VB socks as well if that is an issue for you. As far as the pants go I guess it would depend on how much moisture you feel you lose through your legs. For most people a pair of VB briefs would work because the main concentration of sweat glands is in the groin rather than the legs. Try to think about it in terms of that; large concentration of sweat glands in the groin and pits; and for some reason my feet sweat; best combo for me would be a shirt, briefs, and socks. Try to think where you remember losing most of your moisture if it is sensible.

Glen, I agree, the VB clothing is more versatile in that it allows you to layer clothing on top and you can use it while at camp. I'm not sure you could get away with just a shirt though, as when I use the liner, I don't see areas that have more "dampness" then others - I'd say it's pretty even. While I'm sure certain areas of the body expel more sweat then others, after a long night I think you would either have to cover up everywhere or face the consequences...just thinking out loud here, not from experience, so maybe someone can give us both some insight.
FWIW, I use a VB liner, but only because it comes in at 5 oz vs the clothing which I believe is substantially more. If you find something lighter, let us know! :)

> but when I sleep and perspire; one of the number one spots is my feet.
Dunno whether my feet perspire that much compared to the rest of me, but they don't give off as much heat as my torso. Combine that with the fact that I was trying to dry my ski socks in bed by wearing them under my (dry) bed socks on my last trip, and you can maybe see why there was some condensation on the outside of my quilt over my feet in the morning, but not elsewhere. It reached -6 C overnight (snow trip).

Thing is, I wanted to dry my socks! And in the circumstances neither a VB liner nor a DriLoft shell would have been any use here at all. However, by the time we had eaten breakfast and a bit of sun had come in the end of the tent, the moisture had largely evaporated.

Cheers

I'm very fond of my "Depends" underpants. They might also be useful as VB liners, but I haven't tried that out.

Is it a matter of ventilation in your tent?

My winter trips are limited to 4 days or less, I have an Epic shelled Nunatak Arc Alpinist with 4oz overfill that I have not had problems with condensation. I am usually in my BD Firstlight tent, with roof vent and front door partially open.

Just a guess.