Can you sleep with a tight hood, from which a small hole only be submitted nose and your mouth? If the answer is “no” correct down by 3-5 degrees expected at very low ambient temperatures. Moisture. Camping there in an atmosphere where despite your efforts are likely to dampen the sack? If so, adjust down by 2-4 degrees for synthetic heard by 4-5 degrees feather. Movements of the body. Rotation and turning into the sack act as a pump that pushes warm air out. If you sleep restlessly adjust down by about 2-4 degrees. Wind protection. Four-sleeping in a tent, correct up to 3 degrees; in trisezonna tent – without correction; under the stars – down by about 3-4 degrees.
Wind felt much less if the external fabric of the bag is tightly woven microfiber or laminate as Dry-Loft or Stormlight. You should have already acquired a good idea of how to adjust according to their own needs the testimony of sacks placed by manufacturers to conform to the minimum expected of you outside temperature. If ultimately calculations have led you to a temperature that is ridiculously low (eg minus 35 or 40 degrees), which on top turns and beyond your financial capabilities, orientation to sack a slightly higher temperature, up to clothing and protect the feet during sleep, as well as using the bivouac sack of winning additional 5 degrees. Fillings and fabrics fabrics There is no consensus about the best cloth. Often bags are made from tightly woven fabric with sustainable water-repellent coating. The more tightly woven fabric, so it is more water- and wind tight. Check carefully around the bag to skip filling, which is a sign of insufficient tightly woven fabric. The fabrics range from simple, smooth polyester / nylon fabrics to those laminated with waterproof Gore-Tex.
Most have heard the market uppers of densely woven polyester or nylon microfiber, which is flexible, light and somewhat waterproof and windproof. Ripstop other good stuff since this nylon fabric is extremely durable. A small percentage of bags are made with top, laminated with Gore-Tex or Dry Loft. Gore-Tex is generally not recommended because they do not breathe well enough to pass the body moisture out. Dry Loft, also produced by Gore, breathe better and is more waterproof than most microfibers. Usually internal fabric bags is also artificial. However, there are bags that are inside with a cotton cloth. In such bags are sleeping more comfortable, but the downside is that they are heavier and cotton is not as rugged and durable as nylon and synthetic fabrics. However, if the weight and volume do not bother you so much, we recommend these military sleeping bags. If you take good care of them, they will last many years. However, if the sack you with artificial fabric inside all is not lost. You can sew a cotton bag from a large sheet and stuffed in it before entering. This will warm you and will sleep more enjoyable. Furthermore, this bag can be washed easily, and thus protect heard from too frequent washing.
Filling question is – fluff or synthetics. For most amateur buyers whether to invest in fluffy goose down bag or cheaper filled with fibers, a real dilemma.Insulating material placed between the upper and lining fabric with different methods (channels, layers, cameras). Check how well the filler is distributed in sacks. Shake the bag and check how filling stands in its place. Insufficient number of channels, chambers or layers can cause a buildup of filling in separate areas (often far from the place where your body needs most heat), which damages the highly thermal insulating properties of the bag. If camping with car or rely of common their backs on one sherpa, synthetic bags are a good choice. In the same thermal insulation properties they are heavier and more bulky than the down, but do not lose puhkavinata over time. The requirements for maintenance and ventilation after each use to avoid wetting the same. Synthetic bags also retain much of their insulating properties when wet. But if you want to move with light and less capacious luggage must choose Puhalo. It is “Mercedes” when the filler having a higher ratio of “weight / heat” from any synthetic filler in the market. At the same time, if you get wet, you expect a cold night. Down also dries longer than synthetic fibers. The synthetic filling occurs in different varieties and surprising variety of trademarks. Technologies for production here is improving continuously, material characteristics (weight, termoizolitsiya, susceptibility to compression) approach closer to those of Puhalo. For best performance look for bags filled with Lite Loft, Polarguard 3D, Thermolite Extreme, and PrimaLoft Sport (previous PrimaLoft 2).
Manufacturers of synthetic fillings change some characteristics of the fibers to achieve better insulation weight. They change the diameter of the fibers, their length (from a centimeter to a long continuous filaments), the shape of the cross-sectional size and shape of the apertures or voids in the fibers themselves. There is also diversity in thickness, the density and weight of the filler. Downy bags have identification number of the filling. This number indicates how much space can fill one ounce of fluff used (slightly less than 30 grams). The larger this number is, the sack is fluffy and warm. Over 600 dobre. Must is yet to know that in each bag there are few feathers. This is because it helps insert not quite steps.