For a long time I had asked myself the question, whether for shorter trips with few overnight stays a luxury bivy bag with linkage would be worthwhile. Now I had the opportunity Helium Bivi from Outdoor Research try.
My previous bivy bag has no linkage and can not be closed with a zipper. Luckily I did not use it in heavy rain. But he is super easy. As a main drawback, however, I feel that the actual bag hangs in the face. Although this can be improved with a baseball cap, it is still very uncomfortable - especially because the bivy sack, wet from condensation, gets wet in the face.
That's why I've been on the lookout for luxury bivouac sacks for longer, with poles that at least go over the top of the head and hold the case away from the face. For most bivi bags, however, I find that the weight difference to a one-person-tent is no longer sufficient. Although such tents seldom weigh less than 1 kilogram, you have the better comfort. You can easily turn in it, and the luggage is usually even room.
For individual planned nights had therefore an alternative ago, which weighs well under 1 kilo. However, many do not exist in this weight class. The Helium Bivi of OR actually belongs here rather a niche.
facts and figures
The bivy bag weighs about 510g and is slightly more spacious in the head area. Using a pole creates a small space in the head area, which keeps the 'tent wall' away from the face - not very much, felt 7-10cm distance, but sufficient to have free space above the head.
The size is sufficient, my iso mat and the sleeping bag fit easily into the interior. Even my little backpack still fit in the headboard. Through the bottom of the bivy bag also contains my inflatable mat additional protection of sharp stones or branches on the ground. In the head area there is still a bag for smaller things.
The test overnight
The weather was not very good, but bad enough to make a real test. During the night, the temperature definitely fell below 0 degrees, as I noticed a frozen outer skin during a small night photo session.
The construction of the Helium Bivy is like any other bivy bag also. Simply roll out and then insert the rod. Finished. There is the possibility to fix the bivy bag on the ground, which I did not use, because my backpack made the necessary stability in the head area. Then insert mattress and sleeping bag, the former can also be secured with loops on the ground to prevent slipping. Done is the sleeping place. If you want to save another 57g you can also use a loop without a pole to brace it, which I did not test, because I generally find 'self-contained' systems quite comfortable.
Since a bivy bag is effectively a plastic tube, it is recommended not to close the zipper completely, which definitely leads to lack of oxygen. But since the zipper is at the head end, it can be left unproblematically a little open. As practical it has been found to have the backpack in the head, as this has placed so the bottom pan of the bag and thus the zipper is kept beautifully vertical. As a result, the ventilation slot can be well covered by the overflow and it does not penetrate even when it rains.
Before the rain in the morning, the bag has protected me in any case well. Due to the very high humidity, the Pertex Shield + membrane was not very helpful. On the inside had therefore formed condensation. This was kept away from my face by the 'roof'. In the summer you can stay overnight with the fly screen even in better weather, but still be spared from insects.
Packed the whole thing was just as fast as unpacked - and has even fit in the packsack! I can not say that from my emergency bivouac sack in the first aid kit, which is still in the original packaging, because he would certainly not fit in there. However, I transport the yes only for actual emergencies on day trips.
I'm happy with the helium Bivi. For lightweight tours with 1-2 planned nights, the bivy bag is great. If it takes longer or less on volume and weight, but of course a tent is more comfortable. But the Helium Biviy In fact, compared to regular bivy sacks, it offers so much more comfort that it's worth the extra weight.