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[at-l] Sleeping Bag Use and Care. (long)

Information on the select and care for sleeping bags.

Wildbill

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How to INTELIGENTLY Select and Care for Sleeping Bags

Investing in a good sleeping bag can make the difference between being
miserable every time you go out and getting a peaceful night's sleep.
Similarly, choosing the right shape, size, insulation, and temperature rating
for your needs will ensure less hassle and more comfort and convenience.

TEMPERATURE RATINGS

Warmth is a subjective number.  There is no standard measure of temperature
ratings among sleeping bag manu-facturers.  Basically, it means that: A given 
sleeping bag should keep the average person warm, in still air, while sleeping
on a suitable insulating pad. "Average person" is also subjective.  Some
people sleep warmer or colder than others, so a slightly warmer or cooler bag
may be desired.  "Still air" means sleeping in a tent or other shelter (even a
snow cave) that will prevent air from blowing across you.  If you like to
sleep "under the stars" a lot, consider a bag that is 10 to 15 degrees warmer
than one you would use in a tent.

A good insulating sleeping pad is crucial for taking advantage of your bag's
warmth.  Once you lay down and compress the insulation on the bottom of your
sleeping bag, it loses the thickness that keeps you warm on the bottom. Thus,
a pad is necessary to give you the insulation needed to protect you from the
cold ground (which is always colder than your body temperature). Note that a
simple air mattress does not provide insulation, only cushion. The chambers of
an air mattress are large enough to let the cold ground cool the air inside
the mattress, which cools you!

For most backpacking, bags rated from 10o to 30o are suitable.  What is best
for you depends on where you use it the most (Southwest deserts or high
mountains?) and how warm or cold you sleep.  Don't forget that even in the
summer, high mountain elevations and clear skies at night can mean frost, or
even freezing temperatures!

A winter/expedition bag will generally fall between a 0o to -40o temperature
rating.  These bags are a great choice for use primarily in the colder months
and climates.  It may seem like a great idea to buy a -10o bag to use year
around, but remember: When it's 45o out, you will wish you had carried in a
bag that weighs 2-3 pounds less that doesn't make you sweat like a pig!

A camping or recreational bag is best suited for family or car camping. They
usually have a rectangular shape and a temperature rating of about 30o to 55o.
They are roomy and comfortable, but their bulk, weight and the insulating
inefficiency of their shape make them impractical for backpacking.

FILL WEIGHT AND LOFT

FILL WEIGHT, without reference to a calculated temperature rating or fill
loft, is an antiquated term that does not give any indication of a sleeping
bag's warmth.  LOFT is the important factor, and has no relationship to fill
weight.  The design features that a manufacturer uses to shape their bag, and
the insulation type and quality they choose, determines the loft of a sleeping
bag.  Loft is the feature of the insulation that actually keeps you warm (ie.
loft is what creates  the tiny "dead air" spaces in the insulation, which
traps and retains your body heat in the sleeping bag).

TYPES OF INSULATION, OR "FILL"

DOWN is the soft under feather of geese and ducks.  It has the advantage of
being the most compressible, lightest and warmest fill for a given amount of
loft.  It's biggest disadvantage is that once it gets wet, it has no
insulation value whatsoever until it is completely dry again.  Down bags can
also be quite expensive, but properly cared for they will literally last a
lifetime!

The quality of down used in a bag is an important consideration.  Good down
bags are constructed with 550, 650, or 700+ fill down.  These numbers indicate
the number of cubic inches one ounce of down will loft to in a uniform test.
Theoretically, a bag using 700 fill down will require 21% less fill, and
therefore be lighter than a comparable bag using 550 down fill.  A 700 fill
down bag will likely be considerably more expensive than a 550 fill bag, but
the few manufacturers that use 700 fill make some of THE best bags you will
ever find.  And with the right care, a good down bag can literally last you a
lifetime.

SYNTHETIC FILLS include Polarguard and Polarguard HV, Hollofil II, Quallofil, 
MicroLoft, LiteLoft, and Primaloft.  These are brand names of the most widely
used synthetic fills.  A bag listing a fill of Hollofil 808, or no fill name
at all, should be avoided as they don't have the durability of the better
fills.

Depending on the fill, they are somewhat heavier and bulkier than down, but
are less expensive, and most importantly: they retain most of their insulating
value even when soaking wet...and they dry faster.  Synthetics are a practical
choice for many people, especially with the new micro fiber fills (MicroLoft,
LiteLoft, Polarguard HV, and Primaloft), which rival down's weight and loft
performance without it's disadvantages. 

CONSTRUCTION AND FEATURES

All functionally good bags will have an offset construction.  That means that
there are "bats", or layers, of insulation sewn to the outside shell of the
bag, and bats sewn to the inside shell of the bag.  This is done in such a way
that there is always insulation between you and the outside shell of the bag.
A bag with "sewn-through" or quilted construction should be avoided:  it
leaves cold spots where the seams go through the bag.

The shape and features of the bag make a difference as to it's performance.  A
mummy bag is tapered to the shape of the body.  This means less materials 
used (less weight) and less space inside the bag.  Less space means less heat 
your body has to produce to fill it with warm air, which means you stay
warmer.  All good bags should have a draft tube; an insulated tube or flap on
the inside of the bag which keeps cold air from coming in through the zipper.
Another useful feature is a hood.  Since a majority of body heat escapes from
your head and neck, a hood allows you to insulate your whole body and leave an
opening for your face.  Some cold-weather bags even have an extra draft tube
around the neck, chest and shoulders.

GORE-TEX:  Many people ask about down sleeping bags with a Goretex shell, yet 
there are many misconceptions about what they are supposed to do.  So what 
are Down-Goretex bags best used for?  The answer is simple:

Down-Goretex sleeping bags are the best for extreme arctic climbing conditions
when weight and space are critical and a dry sleeping bag means the different
between life and death.  On high, cold routes, every ounce you can eliminate
from your pack increases your chances of success.  Down-Goretex bags are not
for your favorite canoe trip or wet-weather destination, and are not designed
to take place of a tent or shelter for sleeping in the rain.  If your trip
includes water, and it's not frozen water, then a high-quality synthetic bag
is your best answer.  A plain nylon shell will breath far better than Goretex.
But when the water you're sleeping on is frozen-snow or ice-and the slumber
temperature dips below 0oF, it's time for the down-Goretex bag.

CARE OF YOUR BAG

Proper care will make your bag last longer and work better.  NEVER leave it
stored in a stuff bag when not in use.  Leaving it compressed for long periods
reduces the loft--and that's what keeps you warm.  Periodic washings are a
must, but NEVER DRY CLEAN your bag.  Dirt and oil from your body accumulate
and reduce the efficiency of the fill.  We recommend using Cold Water Woolite
for both down and synthetics, used only in a commercial front-loading machine
in a laundromat.  Top-loading agitator machines will tear up the internal
stitching!  Be careful when lifting a wet bag--the weight of the water in the
fill can also rip out the stitching.  Dry on low heat in one of the big
commercial dryers.  An old, clean sneaker or tennis ball in the dryer with a
down bag will break up clumps and restore loft.
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There was research done on the Performance of Filling Material. This was
conducted at the  Institute for Environmental Research, Kansas State
University.
A report on this research can be found on the polarguard web site.

Report on The Performance of Filling Material.
URL:  http://www.polarguard.com/reporton.htm


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From the Feathered Friends FAQ  URL:  http://www.halcyon.com/featherd/
12. What’s the best way to store a down sleeping bag?

Down can be stored partially compressed, but it should never be stored in
anything watertight. Condensation can occur on the inside of a waterproof bag
and result in mildew. Store your bag in a dry place that has fairly constant
temperature. Do not expose the bag to sunlight except to dry. UV radiation
degrades the nylon and heat evaporates the oils from down. You can store a
sleeping bag either loosely bundled in a cotton storage sack, laid out flat
under a bed, or hung vertically in a closet. We have cotton storage sacks
available if you chose the former method.
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