How do you find a good bag that suits you and your camping conditions? First, take a reading of your personal thermostat and how you sleep in the field. Are your teeth chattering while your tent mate comfortably snoozes in an identical bag? If so, you should opt for a warmer-rated bag than recommended for the average soul. Do you overheat inside your -30 F expedition bag on the coldest nights? Then you could have saved yours the weight and money with a lighter, cheaper sleeper.
Second, consider where you're headed. For sea-kayaking the Labrador coast, you'll need a different bag than for canoeing the Rio Grande. In the first case, a warm, quick-drying, compressible bag is essential. In the second case, almost any lightweight sleeper will do. Certain environments demand more specialized tools.
Finally, borrow or rent your most likely sleeping bag
candidates and conduct a controlled experiment. Try the bags yourself in the
backyard or on short local trips before you venture into the freezing back of
beyond. If you follow these simple steps, peaceful slumber should be yours
wherever and whenever you go.
Type
of Bags
The shape your in, your physical shape, as well as the
bag’s configuration, makes a big difference in how warm you sleep. A bag that
is too big won’t be as warm as one with less space for your body to heat. But
if the bag is too tight, you will compress the insulation that won’t be able
to keep you as warm as it could.
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Mummy Bag: Narrow
at the feet, wider at the shoulders, and tapered to an insulated hood, the
mummy design is the most popular design with wilderness travelers.
The design is the most restrictive shape, but other advantages
include: the hood limits heat loss; the slim cut warms efficiently; and the
trim profile reduces bulk and weight in your pack. |
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Rectangular Bag:
This design offers more room but significantly more heat loss due to the
additional space to be warmed and the gaping
top opening. This design is not used by weight and space conscious
travelers. |
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Semirectangular
Bag: This design splits the difference between mummy warmth and
rectangular roominess. A SR bag usually tapers at the feet and shoulders,
offers a midlength zipper, and is cut to a moderately form-fitting shape. If
the bag doesn't have a hood, keep shopping. |
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Child's Bag:
Kids have more surface area for their weight, causing them to chill more
readily than adults do when asleep, so tucking Junior into your hand-me-down
bag isn't fair. Instead, choose a hooded mini mummy matched to the child's
smaller shape. The hard part comes in allowing sufficient growing room; buy
a child's bag only moderately oversized, then hand it down or trade it in on
a larger one. |
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Liner Bag: A
light insulated liner helps stretch a midweight bag for use in colder
conditions. A liner may add 20 degrees of blessed warmth, and can substitute
as a lightweight bag on balmy nights. An uninsulated liner sheet keeps your
nice bag clean despite your grubby body, and less laundering helps the bag's
insulation last longer. |
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Vapor Barrier
liner (VBL): This is a non-breathable fabric that is used to increase
the warmth of a bag usually around 10 degrees. It can only be used inside
your regualr sleeping bag when the outside temperature is below 0 degrees.
It is clammy but warm. |
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Overbag: An
insulated overbag generally adds about 20 degrees to your bag's comfort
range. Opt for an overbag if sneaking a liner inside your regular bag would
make things uncomfortably tight. |
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Bivouac Sack: A bivy sack is an uninsulated overbag designed to resist inclement weather. Most bivies provide enough wind resistance to add about 10 degrees of warmth. many feature bug netting over the hood opening. Don’t expect a bivy to keep you bone dry in extended downpours. Be sure to get factory sealed seams. |
Sizes
A good fit allows you to stretch out without too much extra space inside to warm up. Get a slightly longer bag for winter camping to store water bottles and boot liners in the foot area to keep them from freezing overnight.
Bags come in regular length, fits up to 5’9” or large fits up to 6’3”.
Temperature
Ratings
Temp ratings are about as reliable as a used-car salesman's prattle. Regard the ratings as a starting point and nothing more. Never choose a bag solely on its temperature rating. There is no industry-standard test for temp ratings, the numbers are virtually useless for comparing bags from different makers. The ratings will, however, tell you where a bag fits in a particular manufacturer's line. Just
remember that simple numbers can't account for:
1) your physical state
2) the quality of your shelter
3) the quality of your sleeping pad
4) how well you're dressed
5) what you've eaten
6) if you had enough water to drink during the day.
If in doubt, choose conservatively. The only sure thing is
that lower temperature ratings mean higher prices. The best all-around sleeping
bag for spring/summer/fall backpacking in temperate regions is a basic mummy in
the 20 F range. A so-called "summer bag" rated at 40 or 50 F might be
great for coastal Carolina or balmy
Baja, but it offers limited utility any place colder. For winter trips to the
Rockies, Sierra, or southern Appalachians, try a snug 0 F mummy. Only winter
die-hards headed for northern New England, Alaska, or the great North Woods need
to pop for a pricey -30 F "maximum mummy," which would be too hot for
sleeping comfortably above freezing.
Shell
Material
The shell provides a bag's first line of defense against
drenching dew, leaky tents, and coffee spills. Shell fabric must somehow perform
against all of the above elements, yet still let your perspiration escape so you
don't soak the bag from the inside. Dark-colored fabrics sun-dry faster than
light hues.
Ripstop Nylon:
Ripstop's distinctive little squares of heavier threads distribute stress and
limit the spread of minor rips. It's exceptionally strong and wind-resistant for
its weight, but it isn't overly water-repellent. It relies on something else (a
bivy sack, Gore-Tex, or a good tent) to fend off moisture. Regular
1.8-ounce-per-yard ripstop makes a serviceable, yet stiff lining material. The
superlight l.l-ounce version feels decadent by comparison.
Nylon Taffeta:
Flat-woven taffeta exhibits a softer texture than ripstop, but it isn't as
strong for its weight and rates only fair for wind resistance. Plain taffeta
usually exhibits all the water-repellency of a sponge. It's often used as a
luxurious inner lining.
Waterproof/Breathable
Fabrics: High-end bags often incorporate a waterproof/breathable shell
fabric for weather armor. High-tech textiles like DryLoft, Gore-Tex, microfibers,
and sundry proprietary fabrics shed snow, rain, and spilled soup, but let
perspiration pass through the shell so your body heat can dry the bag from
inside out. Since the seams aren't sealed, these fabrics won't make a bag
waterproof, but they generally repel enough moisture and wind to extend the
temperature rating by 10 degrees.
Fill
Material
For backpacking use, the best fill delivers the most
insulation for the least weight and bulk when stuffed. A bag insulated with down
used to be the lightest, warmest, and most stuffable, but you either went
bonkers keeping it dry or froze miserably if it got wet and lost its insulating
capabilities. And the old synthetic bag would keep you reasonably warm if wet,
but you had to tolerate a weighty lump that ate up half your pack space.
Down: Down fill
is marvelousIy light, warm, and remarkably packable. It requires careful
cleaning and storage, but a well-kept down bag retains its loft about three
times longer than most synthetics. The downside of down? When wet, it loses all
of its insulating ability and does not field dry easily.
Synthetic Fills; These materials have not matched the warmth, weight, and compessibility of goose feathers (down). They do have some advantages such as retaining much of their insulating capability when wet, field dry quickly and are less expensive. These fills fall into two categories:
short-staple where short fine fibers are heat or resin bonded into a fluffy mass. This fill material packs smaller and is slightly warmer for a given weight than the continuous filament fill materials.
continuous filament where batts of long fibers are quilted or layered together. This fill material holds it’s loft longer than the short-staple fill material.
Synthetic bags should be laundered two or three times per
year with life expectancy of around four years before the loft starts to fade.
Types of synthetic
fills
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Coolmax : Hydrophobic (water hating) polyester fiber with strong wicking action. |
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Down: Pumules from underneath the adult birds outer feathers. Fill power refers to down’s resiliency or loft: 550 down is the basic good quality variety; 650 or 750 fill is the fluffiest, lightest available. |
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Dryloft: Waterproof breathable fabric used to replace gore-tex. |
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Gore-Tex: A microporous membrane laminated to an outer fabric that provides a waterproof barrier yet allows body moisture to escape. |
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Hollofil: A low-priced polyester insulation |
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Lite Loft: A premium synthetic fill. |
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Lamilite: Wiggy’s proprietary synthetic is a continuous-filament polyester fiberfill laminated to the outer fabric shell. |
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Microfiber: Extremely fine, tightly woven fiber that offers natural breathability and wind/water resistance, but it is not waterproof without an additional laminate or coating. |
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Microloft: A new polyester fill made up of microfine fibers thinner than human hair. |
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Polarguard: A continuous filament polyester that was one of the first lightweight fiberfills. and is one of the longest lived fills but bulky to pack. |
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Primaloft: Remarkably water resistant. |
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Quallofill: This material loses loft quicker than most
others. |
SEVEN KEYS TO
GOLDEN SLUMBER
Most importantly, how you use your sleeping bag affects how
warm you'll be. Here are some tips for sleeping comfortably..
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Any bag fresh out of the stuffsack isn't as warm as it
should be because the insulation is still partially compressed. As soon as
you pitch the tent, unstuff your bag and let it regain its full loft. The
longer, the better. |
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A sleeping pad not only keeps rocks and roots away from
your spine, it keeps you warmer by cutting conductive heat loss underneath
your bag. Forget the wheezy old five-tube air bed, and opt for a closed-cell
foam pad or self-inflating foam mattress. Seasoned winter campers use both a
full-length foam pad and a self-inflating mattress on top. |
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"Warm when wet" is a distinctly relative
term. Any bag feels awful when soaked. Carry yours in a waterproof stuffsack;
even a garbage bag will do. Maintain the outer shell's water-repellency with
periodic spray-repellent touch-ups. Even then, be militant about keeping
bags away from wet gear inside the tent. Store soggy stuff in the vestibule
or in a corner away from your bag. Condensation on tent walls can shower
everything inside, so keep a vent cracked to minimize water buildup. |
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Air-dry your bag whenever possible; a sun-warmed
boulder is an ideal place to drape it. In damp weather, hang your bag inside
the tent to dry. |
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In cold weather, always wear a warm hat when sleeping
since half your body heat escapes through your noggin. Wearing long johns
and pile gear to bed often makes the difference between snoozing and
shivering. |
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Food is fuel, so top off the tank before bedtime.
Here's the perfect excuse for high-calorie bedtime munchies ("But I
need to eat all the aricot bars . . .") Between bites, chug lots of
liquid since dehydration leaves you cold, cranky, and listless. Drink your
fill before retiring, drink when you wake at night, and drink whenever else
you can. You know you're swigging enough when you urinate four or five times
daily and the output runs relatively clear. The dreaded "yellow
snow" signals dehydration. |
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Don't simply crawl exhausted and freezing-cold into the
sack. A bag can't retain body heat that isn't there in the first place. Eat
a hot dinner, enjoy a steaming-warm drink, and go for a quick moonlit stroll
to warm up before retiring. But be sure you don't get overheated and go to
bed sweaty. provide enough wind resistance to add about 10 degrees of
warmth. Many feature bug netting over the hood opening. Some bivies border
on being mini tents, with arched poles to keep the sack off your head. Don't
expect a bivy to keep you bone-dry in extended downpours. But, in fairness,
most work great in benign conditions. Nonetheless, insist on factory-sealed
seams. |
Pad Types
To decide which pad fits your needs, you'll have to rank
warmth, weight, comfort, durability, and bulk in order of importance. If you can barely fall asleep on your
king-size water bed, better get the deluxe 2-inch-thick, full-length,
self-inflating mattress, and never mind the weight. If you're the type that can
happily conk out facedown in the talus, a 3/4- length, 3/s-inch-thick
closed-cell pad will suffice.
Closed-Cell Foam Pad:
If you're a minimalist who's hard on gear, get one of these. The individual
bubbles making up the slabs of foam are whole and unbroken (closed), so the
material won't absorb water. Plain cross-linked polyethylene foam pads are the
cheapest type, if a bit stiff. Manufacturers often add a little EVA (ethy-lene
vinyl acetate, a rubbery polymer) for softness.
A closed-cell pad offers enviable cush-per-pound and
warmth-to-weight ratios, but is bulky when rolled. Lashed onto your pack, it
tends to catch on brush and boulders. A closed-cell pad tough enough to use on
bare rock. A campfire spark might melt a minor hole, but the pad will still
work. On the other hand, nobody is likely to mistake a 3/8-inch slab of
semirigid foam for a featherbed. Those unaccustomed to sleeping on hard surfaces
may find a closed-cell pad too lacking in comfort.
Open-Cell Foam Pad:
Open-cell foam is the spongy stuff filling your favorite living-room chair. Made
of expanded polyurethane bubbles, open-cell foam contains fewer solid walls than
closed-cell, so it's lighter and more compressible. Trouble is, open-cell foam
exhibits all the water resistance of a sponge, because that's basically what it
is. Some open-cell pads feature a nylon cover to cut moisture absorption.
Self-Inflating
Mattress: This type is a bit heavy but so warm and cushy that even
weight-obsessed long-haul hikers won't leave home without one. This pad encases
open-cell foam in an inflatable nylon shell. It's called
"self-inflating" because the resilient foam interior puffs the pad
right up, and you can blow in more air to suit your back's firmness
requirements. The downside of a
self-inflating pad is that it's a magnet for sharp, pointy objects, and a tiny
campfire spark equals a sudden letdown. Most SI pads can be easily
field-repaired with a small patch kit, and many models come with a patch kit
built right into the stuffsack. A
typical full-length 1 l/2-inch-thick SI mattress has an R-value (resistance to
heat transfer) of 4, roughly double that of a typical 1/2 inch closed-cell pad.
the pad will weigh at least twice as much - generally 2 to 3 pounds versus less
than 1 pound. SI pads cost three to
four times as much as closed cell pads.
Sleeping
Pad Features
Chair Use:
Typically, this types folds in half and buckles together into a sort of sling
chair for serious camp lounging
Multiple Chambers: Some
inflatable sleeping pads have separate chambers so you can adjust the air
pressure for different part so your body. The creases between the air chambers
can leave cold spots.
Nylon Cover: Some
open cell pads armor with breathable nylon cover to ward off premature wear and
moisture absorbtion.
Poly/Cotton Cover: Another
open-cell variation which is not as slippery as the nylon cover.
Pillow: Some
inflatable pads have a fat air chamber at one end.
Ridged Surface: Smooth
foam pads are notoriously slippery. A ridged surface increases the friction
between sleeping bag and pad and improved cushioning.
Repair Kit Standard:
This means the patch kit comes with the pad.
Stuffsack Standard: This
means a stuffsack comes with the pad to protect it from wear.
Length
and Width
A basic full length pad is 70 inches long and 20 inches wide
A basic 3/4 length is
48 inches long and 18 inches wide. Most shorty users stick their empty pack
under their feet for a little more comfort.
Note: Seasoned
winter campers use both a full-length foam pad and a self-inflating mattress on
top.
PAD MAINTENANCE AND
REPAIR
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Be patient and let your self-inflating pad inflate
itself. Blowing it up by mouth leaves lots of moisture inside that can break
down the foam. Damp foam also freezes, making inflating or deflating
difficult in cold weather, when you don't need complications. |
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Store self-inflating pads unrolled with the valve open.
This slows breakdown of the foam and also lets accumulated moisture inside
the pad gradually escape. Store any pad out of the sun in a relatively cool,
dry place. |
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Duct tape is a lousy patch material for self-inflating
mattresses. It works fairly well in the field but leaves a messy residue
that complicates permanent repair. Better to use self-adhesive nylon repair
tape, which you should already have in your repair kit to patch tents or
jackets. Fix pinholes with a dab of seam-sealer. |
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Carry the padmaker's factory patch kit, with the right
glues and patch material for your particular pad. |
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Patch rips or tears, even if they look frightfully
large. Cut the patch 1/4 inch to 1/2 inch larger than the hole, clean the
area with stove gas or an alcohol swab out of your first-aid kit, and apply
your patch. Rounded edges help the patch stick longer before peeling off. |
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If your pad is burned and the hole extends more than
1/4 inch into the foam, the pad is probably doomed because the remaining air
space will tend to split the repair edges apart and a patch won t hold
things together. |
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Some chair kits are just a sturdy nylon envelope into which you insert an existing pad. This type of chair not only coddles your behind, but also armors the pad. |
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2001 Northern Arizona University, ALL RIGHTS RESERVED