Moisture/Condensation

[BillyBob58]

It is always a bummer to hear about all of the condensation some folks get. I am among that group that has not suffered noticeable condensation with my very limited pad use. Limited, that is, except for the HH Super Shelter(HHSS) with it's open cell foam(aka sponge) pad underneath a space blanket(which is a vapor barrier- VB), which has yet another VB- the sil-nylon under cover- on the outside of both pad and space blanket.

Now this(HHSS) I have used a whole bunch over the years- even set my personal best using it(a mere +6F, us poor southern boys don't get hardly any below zero action). I have never been anything other than bone dry, or worst case a few drops of moisture gathered at the low point of the space blanket. I don't know how many, but I know there are a few other folks here- maybe 1/2 dozen or maybe more- that have had the same experience. In addition, Ducttape and 509 something or other have reported way below zero hangs with no condensation problems, using pads only. However, one of the times that I failed to use the inside VB/space blanket, when I woke up I found my synthetic bag and the HH OCF pad were quite soaked with condensation in the foot area(though still warm, didn't even notice until exiting the hammock). So you see, it is possible for me- like every one else- to get condensation under the right circumstances. Also, on at least one cold weather trip where not one drop of rain or snow ever contacted the shell of my bag, when I got home and measured my 7.5" loft bag(top + bottom layers) was down to less than 6". That was from condensation in the bag.

So the question is: why the difference in the amount of condensation people report? I don't really know, except to say it is tricky business. But here is one factor that plays a part, though I am sure there are others: law of physics = condensation(not to be confused with sweat) occurs on cold surfaces. No one ever sees their breath condense in the air or on their car windshield on a warm day, never. So this may be a clue. When I use the space blanket/VB in the HHSS, it is on the warm side of all of the insulation(OCF pad + whatever unused clothing I might add). So it is kept pretty warm compared to the outside VB that is the under cover. In addition to the fact that I never get any noticeable amount of condensation, it stops any body vapor from making it's way into the cold undercover and condensing there. Bet result: all is dry for me.

I don't know how thick your pad is. (Actually, I do: isn't an auto wind shield pad very thin, with very little insulation/R-value? Isn't it mostly just a VB or space blanket like?) But anything you can do to keep the inner surface of the pad warmer might reduce your condensation. Like a VB hung on the other side of the hammock, to block wind and warm things up a smidgen. Especially if a jacket was placed between that outside VB( sil-nylon, or a space blanket) and the pad. Maybe. Or, maybe if a thicker pad is used? ducttape and 509 have not reported problems, no doubt with thicker pads. I didn't have any at a bit below 20F using a 1" thick Thermarest self inflator on top of a CCF 5/8". (but some one is currently reporting problems with a pad in their Amok hammock, and that is probably a thick pad, so..... )

And don't forget: down quilt users do not escape condensation. They just don't notice it as quickly because it is soaked up in the down. If the trip is short, or they have lots of over fill to help soak it up, or if there is adequate sunshine for drying, they likely won't notice. But I'll bet you if folks weighed their quilts or measured loft, even after a week end trip(depending on temps of course), unless they are using VB clothing or liner, they would realize they had condensation inside their quilts. And if they were out a few more days without sunshine, and packing up every morning, they would have issues. If it is cold enough for the dew point to be even 1/4" inside your outer shell, down or synthetic, you are going to have condensation, guaranteed. You might not notice it for a few days, especially if your quilt is rated 10 or 20 degrees warmer than the coldest temp you encounter, but it will be there. Unless there is adequate sunshine for drying. But I won't get any, thanks to my VB clothing.

Good luck on solving your condensation problem!

[OneClick]

And don't forget: down quilt users do not escape condensation. They just don't notice it as quickly because it is soaked up in the down. If the trip is short, or they have lots of over fill to help soak it up, or if there is adequate sunshine for drying, they likely won't notice.

My last trip was a cold and damp one. The first two nights weren't as bad, but the last night hit that dewpoint with the coldest low right at 32°. I noticed all around the footbox, outside of the TQ, was wet. If I were staying another night, and the weather was still damp, I would have been a bit worried. Packing up a wet quilt and then later unpacking it for another night while still damp sucks.

Last winter I had a very troubling experience, luckily on my last morning. The quilt was VERY wet with ice forming inside from what I could tell. Everything outside was frosted over. Basically EVERYTHING under the tarp that wasn't packed away. Lowest temp was -16°F.

This winter I may get crazy with the vapor barrier. It started mostly as a joke, but now I wonder...



If not, I can always cook meth in the woods.

[cmc4free]

If not, I can always cook meth in the woods.

Bring plenty of Funyuns.

[BillyBob58]

My last trip was a cold and damp one. The first two nights weren't as bad, but the last night hit that dewpoint with the coldest low right at 32°. I noticed all around the footbox, outside of the TQ, was wet. If I were staying another night, and the weather was still damp, I would have been a bit worried. Packing up a wet quilt and then later unpacking it for another night while still damp sucks.

Last winter I had a very troubling experience, luckily on my last morning. The quilt was VERY wet with ice forming inside from what I could tell. Everything outside was frosted over. Basically EVERYTHING under the tarp that wasn't packed away. Lowest temp was -16°F.

This winter I may get crazy with the vapor barrier. It started mostly as a joke, but now I wonder...



If not, I can always cook meth in the woods.

Oneclick, cooking Meth in the woods might help pay for those expensive quilts and hanging gear!

But I want to thank you for this post. It is nice for a change to have an experienced hanger and woodsman- some one besides crazy me- showing that, yes indeed, condensation can be a problem even with the most breathable items. You are not going to escape condensation if the dew point is inside of your insulation. You will only have the luxury of not noticing the condensation, until you do. Especially if you have to pack up every morning. And you can imagine how those situation would have gone if you had been on a week long hike into a Rocky Mountain wilderness. Unless you were blessed with a few days of bright sunshine, then you might have been OK. What would have been very interesting: if- before any drying took place- you had weighed your quilts and measured loft once you got home. But we already know- with ice inside the shells- that those things were significantly effected, don't we? Only question is how much. (of course, maybe with dry down, loft would not be much changed? still, ice inside the shell?) I agree with you when you say: "luckily on my last morning.". And lucky for you that you did not have a 3 day hike out. BTW, how long was that trip?

You are not the first person I have known to report ice inside their down. For one example, there used to be a Michigan winter hanger around here- Cryofthewild? - who regularly reported ice in his 15F marmot bag. But, he was a real maniac and I guess it didn't bother him much, using just a base HH Super Shelter with space blanket outside of the insulation, at way below zero. He preferred that, then he would just shake the ice off of the space blanket every morning, formed from the guaranteed condensation he got from doing it that way. But ice in his bag, wow. He was tougher than this southern boy!

[OneClick]

Actually is was about 3mi hike out, but it didn't matter since I slept warm and just dried my stuff when I got home. This was a 3-day trip. -16° first night, no issues. Second night was 0° so there may have been less wind or just of a more damp day in general? Or my body just put out more moisture for some reason? Quilts were nice and dry/lofty after the first night.

Had to check my notes since I never remember anything:

...0° second night. Lots of moisture/frost on hammock, underquilt and top quilt. Felt water inside TQ at one point? Still wet back home as well after lying in Jeep on the way home. Another night would have been impossible...

[BillyBob58]

Actually is was about 3mi hike out, but it didn't matter since I slept warm and just dried my stuff when I got home. This was a 3-day trip. -16° first night, no issues. Second night was 0° so there may have been less wind or just of a more damp day in general? Or my body just put out more moisture for some reason? Quilts were nice and dry/lofty after the first night.

Had to check my notes since I never remember anything:

...0° second night. Lots of moisture/frost on hammock, underquilt and top quilt. Felt water inside TQ at one point? Still wet back home as well after lying in Jeep on the way home. Another night would have been impossible...

Thanks for the info!

[Danalex]

there's always the Big Agnes Sleeping giant memory foam pad but I find it gets cold and takes a lot to heat up

[mad_matze]

So the question is: why the difference in the amount of condensation people report? I don't really know, except to say it is tricky business. But here is one factor that plays a part, though I am sure there are others: law of physics = condensation(not to be confused with sweat) occurs on cold surfaces. No one ever sees their breath condense in the air or on their car windshield on a warm day, never. So this may be a clue.

Well, if condenseation depends mostly on the temperature difference, a warm sleeper would see more of it, wouldn't he? I am a very warm sleeper and had lots of condensation when I tried the HH bubble pad for example, unfortunately. Same story as Tmornstar's windshield shade experience.

[BillyBob58]

Well, if condenseation depends mostly on the temperature difference, a warm sleeper would see more of it, wouldn't he? I am a very warm sleeper and had lots of condensation when I tried the HH bubble pad for example, unfortunately. Same story as Tmornstar's windshield shade experience.

Mad, maybe, but I don't think so. Unless maybe you put out a lot more body vapor than average, then maybe there might be more moisture available for condensation. The key is- the "clue" I was referring to earlier- is the cold surface. The Bubble pad and the Windshield shade share a common trait: they are very thin. Hence very little insulation, both mainly depending upon reflection of radiant heat, not much blocking of conduction going on there. Not much R-value compared to a thick CCF or insulated inflatable pad. So, the chance of that surface staying colder, as your body heat goes right through it and out to the cold air, seems greater. IOW, the chance of the temps of the ice cold outer layer of that thin radiant pad making it through to the inner layer is much greater than with a thick high R value pad. Thus, if the temp of the pad is lower, since condensation occurs on colder surfaces( no doubt about that one), then there might be a much higher chance of condensation occurring on that cold enough surface.

I know I will probably get condensation if I lay on a windshield shade, or if I hang a space blanket under my hammock, or if I lay in an HH Super Shelter under cover alone, without any insulation plus a space blanket on top of the insulation. I say "I know" because I have done it. I have used a sil-nylon under cover underneath a breathable Open Cell Foam HH pad, with no space blanket, and found the foot of my bag and pad soaked the next morning, temps in the high 40sF. Since that pad is breathable, there is nothing to stop my vapor from traveling right through and contacting the COLD outer sil-nylon shell, and boom, there it is: I'm wet. As predicted by the laws of physics. Just like a cold windshield or cold glass.

Conversely, if I take that same space blanket and place it on top of my OCF pad, leaving everything else the same, experience shows that I am not going to get wet and neither is anything else that is under that space blanket. ( I've done it a bazillion times, and so have a few other folks) It most likely will be the same if I place a bubble pad on top of the space blanket, or in the hammock which is on top of the space blanket, or on top of the pad in place of the space blanket. What is the difference? Now the bubble pad and/or space blanket- being on my side- the warm side- of the insulation, are going to be much warmer. Probably well above the dew point. They won't be cold surfaces, or at least not cold enough. And condensation occurs on cold enough surfaces. Or for that matter, cold enough air.

Personally, I have not had a failure of these scientific principles in 12 years of hanging. And it's not because I don't sweat or produce body vapor. I can quickly soak a cotton shirt in hot weather, and by not following these principles I have soaked my insulation in a hammock. But using a space blanket between my hammock and OCF pad in the HHSS, or under my hammock inside a Speer Pea Pod, or a CCF pad under my hammock inside a Pea Pod, or vapor barrier clothing while sleeping in a hammock, I have never been anything but warm an dry doing these things, all of which keep the VBs warm.. Except my over heating feet at 6F, when wearing VB socks inside Polar Guard booties inside a 20F(maybe, at best) TQ foot box. But even that was not condensation, it was my over heating feet sweating. Which I chose to simply ignore until morning. After all, my insulation was not going to get wet, not with those VB socks holding the moisture inside the socks. We don't hear a lot around here about over heating feet at 6F in a (at best) 20F TQ, even with booties, do we? I should start a poll to see how many folks feet have been sweating at single digits. I don't think there are a bunch of us.

[BillyBob58]

Well, if condenseation depends mostly on the temperature difference, a warm sleeper would see more of it, wouldn't he? I am a very warm sleeper and had lots of condensation when I tried the HH bubble pad for example, unfortunately. Same story as Tmornstar's windshield shade experience.

Mad, do you have an UQ? If so, try what I discussed in the previous post some time. Put that bubble pad inside the hammock, or in a pa pocket, with an UQ under the hammock and pad. If I were doing that, I will be dry- and probably a lot warmer than with the UQ alone. Well, at least I will be dry unless I over heat and start sweating. But try that some time, and let me know what happens.