Vtec44
10-15-2007, 10:43 AM
The primary function of sleeping back is to provide you warmth and insulation. Although it can be used to protect you from exposure to the environment, but a tent is better for that purpose. When purchasing a sleeping bag, there are 3 primary things that you need to look at: Design, Fill, and Temperature Rating.
Design:
A standard sleeping back is pretty much a square blanket with a zipper on one, or 2 sides, so that you can fold it in half and zip yourself inside a “bag”. This will work for most campers, but it may not hold up under “extreme” conditions. Newer design mummy bags are better at heat retention because it covers your entire body, including your head where most of your body heat can excape during the night. Also, the zipper portion is shorter compare to a standard sleeping back, so heat a lot of room to escape.
Fill:
Syntheic: It doesn’t absorb water easily, dries quickly, and provide warmth when wet. The draw back is that it doesn’t compress easily, so the bag takes up more room when not in use.
Down: It weights less and retains heat better than synthetic, but costs more and doesn’t work when it’s wet. Although, newer design have a water-resistant shell to protect the filling, so it may work under damp condition.
Other materials: Cotton doesn’t work when wet, provide good heat retention, but heavier compare to the other materials. Although, it’s low cost so common for indoor or warm weather bags.
Temperature rating:
The current temperature rating is not the most accurate method. So, use it as a guideline in addition to fill material and design. Typically, a bag with a rating of 30 degrees should keep you warm when the temperature is down to 30 degrees outside.
http://www.socalcampers.com/2007/10/08/sleeping-bags/
Design:
A standard sleeping back is pretty much a square blanket with a zipper on one, or 2 sides, so that you can fold it in half and zip yourself inside a “bag”. This will work for most campers, but it may not hold up under “extreme” conditions. Newer design mummy bags are better at heat retention because it covers your entire body, including your head where most of your body heat can excape during the night. Also, the zipper portion is shorter compare to a standard sleeping back, so heat a lot of room to escape.
Fill:
Syntheic: It doesn’t absorb water easily, dries quickly, and provide warmth when wet. The draw back is that it doesn’t compress easily, so the bag takes up more room when not in use.
Down: It weights less and retains heat better than synthetic, but costs more and doesn’t work when it’s wet. Although, newer design have a water-resistant shell to protect the filling, so it may work under damp condition.
Other materials: Cotton doesn’t work when wet, provide good heat retention, but heavier compare to the other materials. Although, it’s low cost so common for indoor or warm weather bags.
Temperature rating:
The current temperature rating is not the most accurate method. So, use it as a guideline in addition to fill material and design. Typically, a bag with a rating of 30 degrees should keep you warm when the temperature is down to 30 degrees outside.
http://www.socalcampers.com/2007/10/08/sleeping-bags/