benben4u
10-19-2010, 01:38
its really old down bag and seems to be in great condition (lofty). how can i tell what the temp rating is? i called marmot they said its so old that they dont have it on record. gonna wait till the temp drops and test it out i hope its at least a 20 degree bag:banana:confused::datz:-?:bse
Toolshed
10-19-2010, 07:34
you can approximate by unzipping and unfurling the bag and layng it out butterflied and letting it loft up to its fullest. Then take a yardstick or ruler and measure how high it lofts for the section that covers your chest.
Below is a table from backpacking light that will provide some guidance.
This roughly compares to a table we used years ago when giving winter backpacking workshops, though we used both top and underside of the bag, so the measurements were doubled. for example - a bag with 5-6" of loft was expected to offer protection to zero.
Note that these are not absolutes. Much depends other variables such as on bag size, bag cut, your size (relative to the bag), your clothing, your state of mind, your nutrition and your shelter.
Table 1, Single Layer Loft and Estimated Temperature Rating
Temp (°F) Loft (in)
50 1.2
40 1.5
30 1.8
20 2.2
10 2.6
0.0 3.0
-10 3.5
-20 4.0