Sleeping Bags - Types & Features
Sleeping Bags are your comfort area in your Outdoor Activities. Whenever you are feeling cold and miserable, your Sleeping Bag will provide the warm comfortable cocoon that will get you warmed up again. A lot of the principles mentioned in our section on Outdoor Clothing
also apply to Sleeping Bags. As discussed in our section on Basic Purposes of Outdoor Clothing
, the purpose of a Sleeping Bag is not to warm you up but to maintain your Thermal Equilibrium. In this section, we will take a detailed look at Sleeping Bags.
Sleeping Bag Shape, Type & Fit
Heat loss is always a big problem in Sleeping Bags, especially the heat loss through the sleeping bag opening, your shoulder area, and your head. Furthermore, the more close-fitting your Sleeping Bag is, the less volume of air there will be that has to be heated by your body.
These two principles have led to the following:
- Nowadays, almost all Outdoor Sleeping Bags are 'mummy bags', meaning that they snugly fit your entire body and if fully closed properly, these only leave your mouth and nose exposed to the outside air. By pulling the draw string on the hood of the Sleeping Bag, the air inside the Sleeping Bag is trapped inside, forming a good insulator. Mummy bags force you to sleep on your back, a sleeping position which may not be preferred by some poeple, and many people find mummy bags too claustrophobic. However, they are absolutely the best in cold conditions.
- To ensure a snug fit, many manufacturers give the dimensions of their Sleeping Bags in shoulder-, hip, and foot girth. Special Sleeping Bags for women have a slimmer shoulder and a wider hip area to ensure a snug fit.
- Some Sleeping Bags can be use din warmer conditions by either closing or opening the hood drawstrings and zippers. Most styles have convenient two-way zippers that allow you to open up sections.
Sleeping Bag Fill
The insulation power of any Sleeping Bag is determined by its fill and the ability of the filling material to retain air. Good filling materials:
- are able to retain a lot of air pockets.
- are lightweight.
- are compact when compressed.
- quickly expand.
- are able to insulate even when wet.
- do not give you any rashes or allergic reactions.
At this moment, there are roughly two classes of Sleeping Bag fill:
This is still the preferred material for high quality Sleeping Bags. Specifically, Geese down is known for its great insulation characteristics. It scores great on all the qualities expected from a good Sleeping Bag fill. It takes very little space when compressed and it fluffs up fully and easily once unrolled. Down is often graded in 'Fill Power' which is the space it consumes per weight unit. Good down will be at 500" class="related_products_container"-800 cubic inches per ounce. The only problem with down is that is loses most of its insulation qualities when wet and it is hard to wash and dry. Furthermore, good down is very expensive and some people are allergic to it. So you may want to check your allergies before you buy an expensive Down Sleeping Bag.
- Synthetic Fibers
Modern synthetic Sleeping Bag fills try to combine the qualities of down with better insulation qualities when wet and much cheaper prices. There are many of these synthetic Sleeping Bag fillings and some of the most common names are Polarguard, Hollofil, and Micro-loft.
Configuration of Tubes and Baffles
Many Sleeping Bag fillings, particularly down, are pretty much free-flowing. To keep the filling from building up at certain areas and going very thin on others, Sleeping Bags have sealed off compartments that keep the filling from displacing too much. These compartments could be seen as tubes that run across the Sleeping Bag from side to side. Each of these tubes are connected to the other at the tube walls, or baffles. In most Sleeping Bags, the baffles are about 5-6 inches apart. Most synthetic Sleeping Bag fills are not free-flowing and do not need compartments to keep the fill from moving.
Other Sleeping Bag Features & Characteristics
- Comfort Temperature Rating
Many manufacturers give their Sleeping Bags a comfort temperature rating which is basically the lowest temperature at which an average person will still be able to have a good night's sleep whilst using the bag. Of course this rating is just an indication and you actual comfort rating will depend on many other factors like your tent and the Weather Conditions.
As in all your Hiking and Camping Equipment, you are looking for ways to Minimize your Pack Weight. You are looking for maximum comfort against minimal weight. In general, the lower the comfort temperature rating, the heavier the bag will be.
- Size, Circumference, Volume, and Stuff Sack Size
As explained above, the size of a Sleeping Bag is usually given for the full length and for the circumference on shoulder, hip, and feet height. Another important factor is the volume that the Sleeping Bag consumes when properly rolled up and compressed. This is often called the Stuff Sack Size which is the size of the container that you use to transport the Sleeping Bag.
- Shell and Liner Materials
Just like in Hiking Clothing and Outdoor Tents, Outdoor Sleeping Bags are expected to give good protection against cold weather and moisture while being breathable so that body moisture is able to leave the inner pocket of your backpack. This is why you will usually find the same type of breathable laminates used for Sleeping Bag liners. In most cases, these laminates are treated to make them softer to the skin. Common Tent Fabric Features like ripstop and other re-enforcing features can often be found in Sleeping Bags as well.
Stitches are a possible weak point in your Sleeping Bag's defenses. Stitching that goes through your entire layer (lines, fill, and shell) will definitely form places where heat loss will occur. Tuck stitching is a method used in better Sleeping Bags where the fabric is folded inwards and the stitch is made at the inside. This gives an invisible and protected seam that minimizes the loss in insulation power.
Zippers are another possible vulnerable spot for heat loss. Good Sleeping Bags have waterproof zippers which are protected by draft flaps, preventing heat loss through the zippers.
Hoods are very important as a very large part of body heat loss happens through your head. A hood will seal of the air pocket in your Sleeping Bag and it will insulate your head, leaving only a small area of your face open. Hoods mostly come with either one or two drawstrings that allow you to seal the hood. Most hoods are an integrated part of the Sleeping Bag but some manufacturers create separate hoods that you can use when needed.
To further reduce heat loss through the Sleeping Bag's head opening, some models come with built-in collars. Removable collars make your Sleeping Bag more flexible. Fixed built-in-collars are only for extremely cold conditions.
- Pillow Pockets
Many Sleeping Bags come with special pockets that you can fill to form a pillow. You can either insert an inflatable pillow or stuff it with clothes to increase your comfort level.
- Sleeping Pad Connections
If you find it hard to sleep and roll around a lot, chances are that you will wake up and find yourself beside your Sleeping Pads & Mats. To prevent this, some styles come with special clips that you can use to secure your Sleeping Bag to your Sleeping Mat.
Sleeping Bags come in all colors with fashion sense still playing a powerful role. In general, darker colors sun-dry quicker. Also, stains (if any) are not that noticeable in dark-colored styles.
These are the basic Features of Sleeping Bags. Get familiar with the different characteristics Sleeping Bags can have so you will know what to look for when buying one.
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