Perspiration, fabrics, and sleeping bags

may be more of an issue of the condensation not being able to escape your shelter. what are you currently using?

If I use a bivy, it definitely gets worse. even without a tarp or bivy, if I am in a humid climate like the pacific northwest, it can still be an issue.

Hey Peter, my first thought was perhaps a vapor barrier may be of some help, but now I'm not sure I understand fully.

My understanding is that Pertex is more breathable then eVent, so your situation is definitely unique. Based on that alone, it makes me wonder if there is another variable in the equation. Can you be more specific with some of the situations you have had this problem in? Temp, shelter, bag, clothes, activity level, etc…may help someone come up with a solution for you.

It is interesting. I've had the most trouble in the pacific northwest. I would get damp in just my pertex sleeping bag & cocoon parka with either a tarp or nothing over me. It was damp and the temp about 40 degrees or so. Another instance was in Seattle. It was my first (and last) time using supershelter with a Hennessey Hammock. It dipped to about 30 degrees and I was okay until the wee hours when I began to freeze. In the morning I noticed that the open-cell foam underpad was totally saturated. There was no rain and the undercover was not open. My friend, right next to me with the same equipment (he was using a MH pounder and I was using a TNF propel but the hammock/supershelter setup was identical) had no such problem. I checked his underpad and it was totally dry. I have no idea what to make of all this. Maybe I should just camp in semi-arid conditions or the high rockies and avoid the PNW….

Perhaps consider VBL clothing for sleeping situations. With ‘sensible’ high vapor the skin is thought to shut down vapor production, at least according to the Stephenson line of marketing.

RHB Designs is well know for VBL products and may be another source for information and getting things under control.

Thanks Greg. I guess it's time to do some field research here. My initial thought has always been that I will accumulate a puddle between my skin and the VB, but I may be wrong. In arid climates the rate of evaporation is fast enough to stay relatively dry, but in humid climates like the Olympics, or Hawaii, I will get a little damp against even cotton clothes or sheets regardless of ambient temprature. The VB option, however, may be a better idea than the damp insulators though … or, again, maybe I just do better in arid climates (the simplest but perhaps most restrictive option).