Condensation in Super Shelter with VB or space blanket?

[BillyBob58]

Originally Posted by Knotty
The SS is great, but even there I'm finding moisture. At least its not in my bag or against my skin.

Maybe all this loss of moisture is why I'm usually cold. Too much evaporative cooling.

Is your moisture on your space blanket, if you use one? I would find a few drops on the low point of my SB, either in the SS or PeaPod, but it was pretty minor. I couldn't tell that any of my insulation ever actually got wet.

Moisture in various locations...SB, inside of SS, the ocf pad. Cant find rhyme or reason yet.

That is odd, but you are not the first to complain of this. I get zero condensation under the SB, down on the pad or in the UC, IF I use a space blanket. I have had a fair amount at least one time when I didn't use the SB.

It is hard to understand why a vapor barrier space blanket ( assuming true WP vapor barrier) would allow moisture to pass through to the pad, which is completely covered with the SB/VB.

I'm not doubting you at all, in fact I have seen this complaint before. It is just sort of a mystery to me, and something I have not experienced.

Is it- like with CCF pads- a matter of how much of a back sweater a person is? Though I still don't see why moisture would get past the SB to the pad no matter how much you sweat. Until it pooled enough to over floe the edges of the VB anyway.

Any thoughts on this? Other SS users, what are your experiences re: condensation with and without a true vapor barrier/space blanket?

[MacEntyre]

Could it be that there is an air gap, between the SB and the rest of the bottom insulation, causing condensation?

[Ramblinrev]

I slept last night with just the undercover in place. No pads, no space blanket. I did not seem to have a proiblem. I am guessing mid 60's. I had a light three season down bag over me as a quilt. I did not check for condensation this morning but When I skinned the hammock it seemed dry. Maybe I should ang it up just to make sure. Tarp was hung, but remained skinned all night.

[BillyBob58]

Could it be that there is an air gap, between the SB and the rest of the bottom insulation, causing condensation?

Maybe, but still the persons insensible and sensible perspiration should condense ON the space blanket and stay there. So maybe your back or your clothes or bag might get damp or wet, but the insulation UNDER the space blanket should still stay dry.

Now I normally have very little condensation- often none visible- on the SB. I thin that's because the SB is tight against me and is therefore warm, unlike the cold surface of the UC.

The only thing I can figure is if some how exhaled moisture is getting down in the UC, and then condensing against the cold surface of the UC and the cold side of the pad. Though that seems a stretch, I can see how if you exhaled down into that area, it would condense. But I have never had it happen. But I can think of at least one other person besides Knotty who has reported a similar problem.

If it was going to happen to anybody, it should have happened to KWPAPKE at minus 23F.

[MacEntyre]

Maybe, but still the persons insensible and sensible perspiration should condense ON the space blanket and stay there.

Yes, that's correct.

I was thinking the moisture outside the SB was condensing from the air outside the hammock, via air leaks between the bottom of the hammock and the insulation underneath.

- MacEntyre

[Bumper]

I'm having the same problem: my bag and everything in the hammock seemed dry but the ocf and undercover below the SB were VERY wet in the morning - to the point where the water was pooling.

This was only my second hang but I had the same problem on my first, although I didn't use the SB that time and it was very, very humid. Because of that first experience I made sure I used the SB this time but I did find it kinda hard to position correctly.

I'm wondering if this is a condensation problem due to a warm body (there must still be some heat lost through the SB) contacting the cold night air (temp= high 30's this time). If that is the case, I would expect the water on top of the ocf, not under it? I'm assuming there must be more to it than this or the people using underquilts would have the same problem.

FYI, I'm usually a very warm sleeper who sweats a lot. This particular night I felt quite cool though.

Help?

[MacEntyre]

Cool outside air warms up when it leaks inside the insulation, below the SB. It can then hold more humidity, which it takes from the cooler air outside via the leak. The sleeper moves, a charge of cold air leaks into the insulation, cooling the previously warmed air, which condenses. Leak cycles again, making more condensation. Sleeper awakens, finds water in insulation below SB, but none above. Sleeper is puzzled.

[BillyBob58]

Yes, that's correct.

I was thinking the moisture outside the SB was condensing from the air outside the hammock, via air leaks between the bottom of the hammock and the insulation underneath.

- MacEntyre

Right, I see what you mean. Moisture in the air condensing inside the UC, rather than moisture from the person getting past the VB? Certainly it is not sealed well enough that the air is kept out.

Maybe that is it? Though it seems a stretch. But it seems like such conditions also result ( even without a soaking fog) wet outer shells on clothing even when under a tarp, or more to the point wet UQ inner surfaces? I realize the surface against your back is warm and would not encourage condensation, but there is plenty that is not in contact with your body which would be a cold surface. So it would seem that the same moisture laden external cold air, if condensing on the cold inner surface of the SS UC, would do the same on the inner surface of quilts not in contact with a warm body. The inner surface of a SS is at least as well sealed off from outer moisture as is a down UQ. With the exception of a Pea Pod, which is "sealed" around all edges. But even with the pod, you open it up to enter or exit or vent.

Condensation is not necessarily related to breathable. Moisture can condense on a cold breathable surface. Body moisture can condense inside a down sleeping bag before it ever reaches the outer breathable shell. This happens more than we realize, and explains decreasing loft some experience on longer trips if there is no chance to dry out.

But still, maybe this is what is happening?

Where is Youngblood? Where has he been? This sounds like an subject he would like to comment on.

[BillyBob58]

Cool outside air warms up when it leaks inside the insulation, below the SB. It can then hold more humidity, which it takes from the cooler air outside via the leak. The sleeper moves, a charge of cold air leaks into the insulation, cooling the previously warmed air, which condenses. Leak cycles again, making more condensation. Sleeper awakens, finds water in insulation below SB, but none above. Sleeper is puzzled.

Maybe so! Again, I have not really experienced this. I have never had a drop of condensation except ONE time I did not use the SB in VERY humid conditions. But others have, so?

[Dutch]

Could a piece of sil be used as a vb instead of the space blanket? I know you won't get the radient heat but you should still get the vb and improved dead air space. I just don't like those space blankets.