Poser
WKR
I’ve been using this MLD bivy sack since this summer. No issues during the summer months, but since it’s gotten cold, I’ve had a consistent problem on the left side which is the zipper side. The bottom of the sack is silnylon, the top is E-vent material.
The setup when I’m sleeping:
The right side is enclosed, the left side (the problem side) has a U zipper. I’ve been sleeping in a hot tent with a stove on my right, but if I’m asleep for 7 hours, a stove might be burning for 1 of those hours.
The left side, where I’m getting condensation, is next to the tent door (which has a good amount of frozen condensation in the morning, but no moisture on the top of my bivy sack)
I first experienced condensation on this left side when I was leaving the zipper More unzipped than pictured here. I just spent 3 nights out and zipped it up as shown here and still had condensation on this left side, but nowhere else.
Right side for reference (again, next to the stove but that doesn’t burn most of the night).
The only difference is the presence of a zipper.
Any theories or diagnosis? It’s a minor amount of condensation, an amount that will dry in the sun in under 5 minutes, but I want to understand what is happening to cause condensation in this one spot. I toss and turn constantly all night sleeping on both sides, stomach and back. I’ve been using a bag liner since it gotten cold this season as my quilt is only 20 degrees, but the liner is just a fleece sack so I don’t see how that would contribute to one specific area which is the left side about the length of the torso. Not lower and not at the very top of the quilt.
The setup when I’m sleeping:
The right side is enclosed, the left side (the problem side) has a U zipper. I’ve been sleeping in a hot tent with a stove on my right, but if I’m asleep for 7 hours, a stove might be burning for 1 of those hours.
The left side, where I’m getting condensation, is next to the tent door (which has a good amount of frozen condensation in the morning, but no moisture on the top of my bivy sack)
I first experienced condensation on this left side when I was leaving the zipper More unzipped than pictured here. I just spent 3 nights out and zipped it up as shown here and still had condensation on this left side, but nowhere else.
Right side for reference (again, next to the stove but that doesn’t burn most of the night).
The only difference is the presence of a zipper.
Any theories or diagnosis? It’s a minor amount of condensation, an amount that will dry in the sun in under 5 minutes, but I want to understand what is happening to cause condensation in this one spot. I toss and turn constantly all night sleeping on both sides, stomach and back. I’ve been using a bag liner since it gotten cold this season as my quilt is only 20 degrees, but the liner is just a fleece sack so I don’t see how that would contribute to one specific area which is the left side about the length of the torso. Not lower and not at the very top of the quilt.