Winter bivy sacks have been first developed as solo shelters for mountaineering and climbing the place members have been all for light-weight and really compressible tenting gear. Bivy Sacks are furthermore a surprising choice for backpacking hunters, backcountry skiers, and winter backpackers who need the lightest and smallest shelter they will carry for in a single day or emergency use.
Winter bivy sacks are utterly completely completely different from three-season bivy sacks which are usually used alongside aspect a tarp for insect and splashback safety, the place rain hitting the underside can bounce as soon as extra and moist your quilt or sleeping bag. In distinction, a winter bivy sack is meant as a standalone shelter by itself or alongside aspect a snow shelter just like a trench or snow cave. Winter bivy sacks are usually hundreds bigger in quantity to carry winter-weight sleeping baggage with out compressing the insulation and work most fascinating in dry and chilly circumstances the place precipitation is contained in the type of snow.
Winter Bivy Sacks – Benefits
An essential benefit of a winter bivy sack is the power to put it to use anyplace you wish to cease and sleep. Most fashions don’t require tent stakes or tent poles and so they additionally pack up very small which is a bonus if you wish to defend your winter gear light-weight and compact. Most winter bivy sacks are made with waterproof/breathable prime provides to assist reduce inside condensation and waterproof base provides to maintain up your sleeping bag and pad dry. Insect netting may be obtainable in some chilly native climate bivy sacks and can doubtless be helpful after they’re utilized in spring circumstances when bugs start to emerge,
There are fairly just a few benefits to sleeping in a water-proof bivy sack over a tent. It’s simple to discover a spot to place a bivy sack at night time because of it solely requires as hundreds area as your sleeping pad and sleeping bag. Merely unroll your bivy sack, slip your sleeping pad and sleeping bag inside, and crawl in. This makes them acceptable for sleeping on slim mountain ledges or in forested glades the place there’s merely ample area to lie between two timber.
There are normally not any tent stakes to freeze into the underside so you might get inside immediately and get heat. Being waterproof, you don’t ought to lie on prime of a groundsheet every, because of the underside of a water-proof bivy sack is designed to maintain up you dry. Bivy sacks furthermore add fairly just a few ranges of insulation to your sleep system and make good emergency shelters for solo winter hikers, supplied you carry a sleeping pad and ample insulation to get by means of the night time.
Winter Bivy Sacks – Disadvantages
Bivy sacks are far more confining than tents, with solely ample area for you and some small private units. You’ll be able to’t really do one factor inside one along with take heed to podcasts or fall asleep. It’s awkward to fluctuate out of your moist garments or positioned on dry garments inside relying on the kind of bivy sack you’ll have, it could be rattling laborious to place in your boots, even to go for a pee at night time. There’s no place to retailer your backpack and the remainder of your gear will most likely be utterly uncovered an evening with none cowl.
Bivy sacks are furthermore extra susceptible to inside condensation than a tent, even when manufactured with waterproof breathable offers. You’re most fascinating off holding them open or unzipped at night time to cut once more the temperature differential between the within of the bivy and the ground which causes condensation to kind. Tent condensation happens for a similar motive nonetheless tents have bigger air flow into and additional quantity, so it’s simpler to maintain up your sleeping bag dry when it happens.
Regardless of these disadvantages, I’ve associates who swear by their winter bivy sacks on account of they’re so quick to deploy as in contrast with a tent or tarp. I’ve used winter bivy sacks and should respect their strengths, nonetheless winter nights closing a really very very very long time and it’s good to have barely bit extra area to fluctuate your garments or sleep alongside collectively along with your gear inside your tent. Whichever you select will depend on what you’re making an attempt to hold out.
Comparability Desk
Kinds of Winter Bivy Sacks
There are three sorts of winter bivy sacks to pick from:
- Hooped entrance entry bivy sacks
- Hooped facet entry bivy sacks
- Sleeping bag covers
There are two sorts of hooped bivy sacks: these with entrance entrances that you simply simply slide into ft first and people which you’ll enter from the facet. Each embrace one different quick fiberglass or carbon fiber rods that give sort to the hood and forestall it from collapsing onto your head or torso.
The pinnacle-end of a hooped entrance entrance bivy is usually screened with a gradual cowl that might be zippered closed for heat or to dam wind or rain. This design provides good air flow into in your head and helps to expel the water vapor in your breath. The Exterior Analysis Helium Bivy is an surroundings pleasant event of the doorway entry hooped design.
Aspect-entry hooped bivy sacks usually have a zipper alongside one facet so that you simply most likely can merely get out and in of them. This design may be simpler to vent on account of you most likely can roll up the perfect cowl in dry native climate to cut once more inside condensation. The Exterior Analysis Alpine Ascentshell Bivy is an surroundings pleasant event of a hooped bivy with a facet entrance.
The simplest and lightest weight winter bivy sacks are little bigger than sleeping bag covers. Some have drawstrings which you’ll pull closed over your head, some have normal mummy-style hoods or easy slits above the face for air flow into. Whereas not as livable or well-ventilated because of the hooped bivy sacks designs described above, they do the job should you want a terribly compressible, ultralight native climate safety in your sleep system. The MSR Expert Bivy and the Black Diamond Twilight Bivy are advisor examples of the sleeping bag cowl design.
One of many easiest methods to Select a Winter Bivy Sack
There are a selection of decisions and trade-offs to ponder when selecting a winter bivy sack.
Waterproof/breathable prime supplies
Having a water-proof/breathable prime supplies is essential to vent water vapor and assist reduce inside condensation that can make your sleeping bag moist. Nonetheless, not like rain jackets, most bivy sack producers don’t itemizing the laboratory measurements used to value waterproofing (hydrostatic head, abbreviated “HH”) or breathability (movable water transmission price, abbreviated “MVTR”). That may make effectivity comparisons between utterly completely completely different bivy sacks strong.
Additional headroom
If headroom is essential, think about getting a bivy shelter with a hooped design. These bivy sacks embrace a versatile pole that slides into the hood to create extra quantity spherical your face and shoulders. The tradeoff is that they are usually heavier than extra minimal bivy sacks.
Additional quantity
Winter bivy sacks are usually excessive quantity to swimsuit cumbersome winter sleeping baggage and inflatable pads with a excessive R-value. When selecting a bivy sack you wish to guarantee that there’s sufficient room in your sleeping bag insulation to totally loft and that it’s not compressed by having too tight a match.
Entrance and exit
It’s hundreds simpler to get out and in of a bivy sack that has a zipper alongside the facet than one which solely has a “hatch” on the highest finish, to crawl out and in of. You’ll protect drier if the underside is roofed in snow and it’s hundreds simpler to positioned on and take off your sneakers.
Insect netting for hotter temperatures
Throughout the event you plan to bivy in early spring when biting bugs emerge, be sure that to get a winter bivy sack with a mesh panel over the face so that you simply most likely can sleep with out bugs biting your face at night time. Throughout the event you solely plan to sleep in a bivy sack in winter or in snow caves, a mesh panel will most likely be so much a lot much less essential. For hotter native climate use, I’d encourage you to spend money on an ultralight bivy sack or bug shelter moderately than a winter bivy sack, since they’re hundreds cooler to make the most of. See our 10 Most fascinating Backpacking Bug Shelters for our useful three-season bivy sacks.
Weight and Packed Dimension
Don’t overlook to ponder the burden of the bivy sack and its packed measurement, since thought of one among many chief advantages of utilizing a bivy sack is gear weight and measurement low value. There’s usually a tradeoff between decisions and weight/measurement, nonetheless some winter bivy sacks are surprisingly light-weight and compressible.
Sizing and Match
When unsure, order a bivy sack (verify the retailer’s return safety) and lie in it at residence to see if it suits. It’s going to maybe inform you way more about whether or not or not or not it might be merely greatest for you than evaluating the specs of fairly just a few fashions listed on-line. Examine to easily remember to can suit your sleeping pad and sleeping bag inside, and that the foot space is massive ample in your ft.
Emergency Bivy Sacks
There’s a class of emergency bivy sacks which could be solely supposed for emergency use such because of the SOL Escape Lite Bivy. These are made with skinny reflective aluminized supplies and lack the sturdiness or breathability of the multiuse bivy sacks listed above.
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