Vapor Barrier Liner/Clothing - Sleep System

[Appalaskan]

Does anyone adhere to the vapor barrier philosophy for cold weather sleeping? If so, what’s your routine? Use a liner or VB clothing? Give the rundown on what you’ve experienced.

 

[mtwarden]

If I was planning a multi-week expedition in the winter, I'd consider it, but on week-ish long winter outings I haven't found the need

I have starting using a light synthetic Apex quilt over the top of my down bag- boosts the rating of the sleep system and allows the vast majority of the moisture to move through the down layer and ends up in the synthetic layer which handles moisture a lot better

 

[Appalaskan]

If I was planning a multi-week expedition in the winter, I'd consider it, but on week-ish long winter outings I haven't found the need

I have starting using a light synthetic Apex quilt over the top of my down bag- boosts the rating of the sleep system and allows the vast majority of the moisture to move through the down layer and ends up in the synthetic layer which handles moisture a lot better

How about a VB system for your clothing? Ever tried that? Seems like it’d be strange getting used to, but I get the science.

 

[AkMtnRunner]

I’ve done light windbreakers underneath insulated layers. While it does keep the clothing drier, my skin and inside of the windbreaker get really wet, which is just another problem.

In theory it should work but I’ve found the only way to stay truly warm is moving around often and I will eventually sweat.

 

[Appalaskan]

I’ve done light windbreakers underneath insulated layers. While it does keep the clothing drier, my skin and inside of the windbreaker get really wet, which is just another problem.

In theory it should work but I’ve found the only way to stay truly warm is moving around often and I will eventually sweat.

Yeah, i don’t think it’s feasible to not sweat. Even in -35F I’m going to sweat if I’m hiking. Have to remind myself that winter ventures just take more time to allow for drying out things, cooking...everything.

 

[Marbles]

I have minimal experience with VBLs. So not sure I will tell you anything you don't already know.

I have been thinking about picking up some 1mm NRS neoprene pants/top to work as one. People I have talked to who use them say for comfort it becomes more important to really manage your layers and take thing off before working up a sweat. They also say after a while you get a better feel for your level of exertion and managing that to minimize sweating.

Like a wetsuit while diving, sweat between your skin and the VBL is not an insulation issue, though it can be a comfort issue.

The disadvantage of a VBL sleeping bag liner is you have to sleep naked or have a base layer system you just plan on getting wet as you will be holding all the moister in the bag. This means you cannot wear your puffy to bed as you would wet it out. If you use VBL clothing this is not an issue and you can wear layers to bed.

I think a VBL on the feet is probably most valuable. Even wool and synthetics don't insulate as well when damp.

Another advantage of a VBL is that insulating layers don't really every dry out at below freezing temperatures, meaning you collect moister and don't get rid of it. However, a VBL can be puled off, turned inside out, allowed to freeze, then just shake the ice off.