BPL Vapor Bivy Sack vs. Oware Epic Bivy Sack

I chose the Quantum Bivy. I feel that keeping your bag protected from outside moisture is pretty easy…keep it in a waterproof stuff sack and don’t take it out until it is inside your bivy underneath a well pitched shelter. Protecting your bag from inside moisture is a much bigger challenge. There is no way to prevent it from getting wet from the inside, the only thing you can do is minimize the barrier through which the moisture must pass, so that it can evaporate out of your sleep system at close to the same rate it is being introduced to your sleep system.

I thought I read people complaining about major condensation in Epic fabric in below freezing conditions…the moisture would freeze while passing through the epic fabric, blocking any more moisture from escaping.

As for my own experiences with Epic shelters…if it is wet outside, then it is wet inside too. In normal rain conditions my Epic tent got a little condensation, but because the fabric was not touching my sleeping bag it was manageable. But if that fabric was directly touching my down sleeping bag all night I would be concerned. In very wet coastal conditions, my Epic tent was practically raining inside. I would get woken up by splashes of condensation dripping of the ceiling onto my face. Not a good way to get rest.

Good luck making your decision, I’m sure they’re both good bivys. My Vapr bivy had an Oware tag in it, so I guess Oware makes both of them. The construction is good.

I have an Oware Epic Bivy and have had problems with condensation on several trips. The condensation inside the bivy was bad enough to dampen my sleeping bag and make conditions uncomfortable. The conditions where I experienced problems consisted of temps in the high 30 to low 40 degree range with enough dew or frost to coat the outside of the bivy. I have a hunch that the dew covering the outside of the bivy creates the condensation problems on the inside of the bivy. My only basis for this hunch is that after having condensation problems one night I pitched my tarp the next night and did not have any problems with condensation in the bivy. The tarp kept dew off the bivy (there was dew on the outside of the tarp).
If I had to do it over Im not sure what type of bivy I would get but it would definitely not be one made with Epic.

Michael, I had the same problem with a Gore Tex bivy. I wonder whether, in addition to the dew, a possible reason for the wetting of the sleeping bag might be that there may be too much space between your body and the heat it is generating and the bivy itself, so that the temperature on the inside of the bivy is not sufficiently high to drive the moisture thru the Gore Tex material.
Does anyone have enough experience with a Pertex covered bivy sack to say whether it avoids this problem?

I used my vapr bivy for the first time this weekend, and didn’t have any problems with condensation. Nighttime temps were low of 39 one night and 42 the next. Humidity was moderate to high although didn’t have a hygrometer handy to measure it…

My biggest concern at this point is the durability of the tiny zipper… anyone have experience with this failing?

Thanks,
Jerry

Just curious, did you seam seal your epic tent?

The Bibler Winter Bivy is made of Epic fabric, weighs 8.8 oz (250g) and costs under $100.
I have been considering this one as it is much cheaper than the BPL and Oware sacks.
I know the old addage “You get what you pay for”, but is there that much difference between them?
Anyone have experience with the Bibler?

I have the same questions/concerns about these two bivies. I went back to read a review here at BPL on the Oware Epic bivy. Here it is:

http://www.backpackinglight.com/cgi-bin/backpackinglight/00058.html

In the “Function” section the reviewer says that the testers found no problems with condensation, but in the “Overall Impression” the reviewer writes “Yet the EPIC cover suffers from <<less condensation>> than fully waterproof breathable bivies.” So condensation is an issue.

After reading comments by those who have experienced condensation with the Epic bivy, it seems to me that the Epic bivy is best used with a tarp, which offers superior ventilation and air circulation.

RE: BPL Vapor Bivy. I can see how the BPL Vapor Bivy (with Pertex Quantum on top) provides a waterproof bottom and solves the problem of drafts for quilt users. If the quilt is an Arc X with Quantum, how do the two layers work to protect the down from external moisture, such as wind-driven rain? Is the answer just that, i.e, two layers of Quantum? (By the way, I can’t find the Arc X in the BPL gear shop.)

As the tarp-bivy setup is one of the lightest, most versatile shelter options for the ultralight backpacker, I’d love to hear more from those with thoughts and experiences on this topic.

–Mick

After having spent a couple of nights in my Vapr Bivy I have another observation. The first night I pitched a poncho/tarp over my bivy in low lands surrounded by trees. I slept very, very warm and had no problem with even the slightest condensation. The second night I slept up on a rocky and windy hill. I could not find a site large enough to pitch my poncho/tarp over so I simply staked the bivy sack out and used that as my only shelter. That night I woke up after about 5 or 6 hours of sleeping. The inside of my bag was dry, the outside of the bivy sack was dry, there was no dew on any nearby plants, but between my sleeping bag and bivy sack on top there was major condensation and my bag was very wet on the top half.

I can only guess that the moisture I put out at night got too cold between leaving my body and leaving my bivy sack, so it condensed within my sleep system. I think if I had been able to pitch my tarp it would have sheltered the bivy sack enough that my body heat could push out the moisture, atleast partially.

My Vapr Bivy size long weighs out at 7.1 ounces, plus the bug netting at 1.0 ounce (without trimming reinforcements), suspension cord at 0.1, and stuff sack at 0.3 (after switching cordlocks to a lighter one) for a total of 8.5 ounces.

I don’t have much to add to this except an observation re: zippers. Size
( essentially ) is not the issue in zipper “strength” It’s the number of coils or teeth per inch. Very small zippers can be very “strong”

I have used the Bibler extensively over the last couple of years. Recently I lost it and replaced it with the Vapr because it is lighter.

I found the Bibler great and rarely had significant issues with consensation. Never any issues with waterproofness. Usually even when using it in the rain without a tarp enough body heat is generated to drive moisture out faster than it comes in or condensates.

Over Easter I spent 5 nights in very humid and/or rainy conditions (West Coast, South Island, New Zealand) with the Vapr in a Shires Tarptent or Spinnshelter. One of the guys I was with had the Bibler Winter Bivy so we were able to compare. Overnight temperatures were 5-10°C (40-50°F) and we were wearing very damp clothes to bed. As much as we could tell both bivys performed about the same. The condensation inside the bivys and on the outside of the sleeping bags was very serious on four of the nights. Making the outside of the sleeping bag wet. The outside of the bivys was damp/wet in places some nights and quite dry others depending on the amount of spray off the tarp walls. I believe the heavy condensation was due to high humidity, wet clothes and the temperatures that put the dew point just inside the bivy.

Jerry
I damaged the zipper the first night I used it. I unzipped it until just the little metal tip at the start of the coil was joined, but nothing was zipped up. At some point in the night with struggling to get out of the bag, I ripped the tiny bit of metal right off and now can’t zip it up at all. This is a problem because of the cunning insect mesh insert. Easily avoided by completely unzipping it or zipping it a minimum of a couple of inches.