Sleeping bags The basics and how to stay warm.
I get a lot of emails, PMs, and calls about this stuff. I love to answer them so here is a summary of some of the stuff.
Different types of insulation
Down and Synthetic
Down Pros
Lighter
More compressible
Lasts about 4 times longer
Better for the environment
Can be positioned where needed
Synthetic Pros
Cost is less
Possibility of heat retention when wet
Stays in place better filling wise
Resistant to rot, mildew and smells.
Synthetic bags offer more protection from the ground.
Down cons
Costs about twice as much
Shifts around more without proper baffles
Can leak out of the bag through stitching and fabric
Need to wash more than synthetic
Synthetic Cons
Loses loft faster
Heavier
Requires petroleum to produce
Doesn’t last as long
Types of shells inner and outer
Canvas
Canvas is very durable. Not good at wet weather because it wicks up water like a sponge. It is cool cause you look like a cowboy.
Nylon
It is usually a little water resistant or a lot depending on type of nylon. Can be less durable if it is a cheaper nylon. Ripstop nylon is very durable, but a little rough to the touch. Nylon teffeta is very durable and soft to the touch as well.
Microfiber
Soft to the touch, pretty water resistant, and feather resistant. Almost windproof.
Polyester
Don’t want to talk about it. It varies too much it can be nice or crappy usually depending on how much you spend.
Flannel
Warm but bulky. Flannel is usually made of cotton. When flannel gets wet you will be cold.
Types of bags (this will be brief as most are familiar with this)
Mummy
Not good for the claustraphobic.
Mummies are more efficient at heating up
less wasted space.
weigh less.
smaller in size.
Rectangle
More leg room.
More stuff to heat up.
Greater chance of air escaping around body.
Bigger.
Semi rectangular
In between the other two.
Features to look for
Hood
These keep your head warm and are great for putting you pillow /arm on.
Draft tube
Draft tubes run the full length of the zipper and are used to prevent heat from leaving through the Zipper.
Draft collar
These run around your neck and or chest. These keep warm air from moving past your head while you roll around.
Boxed feet
Keep your toes from being squished
Warmer feet
Baffles
Sewn in side the bag to keep insulation from moving around. These could be considered down dams. Some bags will stitch the inner and out bags together to make baffles.
Down fill power
This is amount of loft per ounce of down. It is done in a graduated cylinder. 550 is bad, 850 is the best. 900 only happens if you wash it and then dry it with an air dryer and set it a little at a time in the cylinder. Not possible in real world.
Sleeping bag care
Wash your bag with down wash if it is down.
Wash it more often than you do (what you can wash sleeping bags?).
Don’t store it in the compression sack. If you bag is synthetic you are destroying about 10 degrees a year when you keep it compressed.
Store it in a breathable laundry bag or cotton sack of some sort.
Don’t store it in a garbage bag.
After you wash it dry it lowest heat with a couple of tennis balls or something with a little mass to break up the clusters of feather to help it loft out.
Sleeping bag warmth
It doesn’t matter what you temperature rating is. Loft is the key. Loft is how “poofy” the bag is. If you want to know the loft leave you bag out for awhile and then measure it from the ground up with a ruler.
Loft is the term for how thick a bag is.
Loft only really matters on the top of the bag as the bottom will be squished.
Loft is loft regardless of the material (of course some exceptions)
2” of down is the same as 2” of newspaper (weight and density will change).
General rules that will differ according to metabolism.
2.5” is equal to about 0 degrees
1.5” equals about 40 degrees
8” is good to about -60
The relationship between loft and warmth is not linear
Tips
Make sure you have calories in your body to burn.
My wife keeps a bag of Hersheys kisses next to her bag when winter camping and pops one in her mouth every couple of hours to add some calories to the system.
Change you clothes, socks, underwear, headgear, everything before you get into your bag.
Nakedness does not equal warmth in you bag that is an old wives tale. This comes from old guys climbing into their bags with wet cotton long johns on. Of course you will be cold.
Sleep socks are awesome, but need to be loose fitting.
You need to be sleeping on a pad. Thermal heat transfer occurs significantly fast with conduction than convection. You pad is MORE important than your bag. (Article on pads forthcoming)
Cover your head.
Vapor barriers can greatly increase your bags warmth, but some feel icky when sleeping in one.
You need to stop heat transfer. You never get cold, you get less warm. Heat moves from hot to cold not the other way.
The types of heat loss are conductive, convective, evaporative, radiative. Slow these down and you will be warm.
I get a lot of emails, PMs, and calls about this stuff. I love to answer them so here is a summary of some of the stuff.
Different types of insulation
Down and Synthetic
Down Pros
Lighter
More compressible
Lasts about 4 times longer
Better for the environment
Can be positioned where needed
Synthetic Pros
Cost is less
Possibility of heat retention when wet
Stays in place better filling wise
Resistant to rot, mildew and smells.
Synthetic bags offer more protection from the ground.
Down cons
Costs about twice as much
Shifts around more without proper baffles
Can leak out of the bag through stitching and fabric
Need to wash more than synthetic
Synthetic Cons
Loses loft faster
Heavier
Requires petroleum to produce
Doesn’t last as long
Types of shells inner and outer
Canvas
Canvas is very durable. Not good at wet weather because it wicks up water like a sponge. It is cool cause you look like a cowboy.
Nylon
It is usually a little water resistant or a lot depending on type of nylon. Can be less durable if it is a cheaper nylon. Ripstop nylon is very durable, but a little rough to the touch. Nylon teffeta is very durable and soft to the touch as well.
Microfiber
Soft to the touch, pretty water resistant, and feather resistant. Almost windproof.
Polyester
Don’t want to talk about it. It varies too much it can be nice or crappy usually depending on how much you spend.
Flannel
Warm but bulky. Flannel is usually made of cotton. When flannel gets wet you will be cold.
Types of bags (this will be brief as most are familiar with this)
Mummy
Not good for the claustraphobic.
Mummies are more efficient at heating up
less wasted space.
weigh less.
smaller in size.
Rectangle
More leg room.
More stuff to heat up.
Greater chance of air escaping around body.
Bigger.
Semi rectangular
In between the other two.
Features to look for
Hood
These keep your head warm and are great for putting you pillow /arm on.
Draft tube
Draft tubes run the full length of the zipper and are used to prevent heat from leaving through the Zipper.
Draft collar
These run around your neck and or chest. These keep warm air from moving past your head while you roll around.
Boxed feet
Keep your toes from being squished
Warmer feet
Baffles
Sewn in side the bag to keep insulation from moving around. These could be considered down dams. Some bags will stitch the inner and out bags together to make baffles.
Down fill power
This is amount of loft per ounce of down. It is done in a graduated cylinder. 550 is bad, 850 is the best. 900 only happens if you wash it and then dry it with an air dryer and set it a little at a time in the cylinder. Not possible in real world.
Sleeping bag care
Wash your bag with down wash if it is down.
Wash it more often than you do (what you can wash sleeping bags?).
Don’t store it in the compression sack. If you bag is synthetic you are destroying about 10 degrees a year when you keep it compressed.
Store it in a breathable laundry bag or cotton sack of some sort.
Don’t store it in a garbage bag.
After you wash it dry it lowest heat with a couple of tennis balls or something with a little mass to break up the clusters of feather to help it loft out.
Sleeping bag warmth
It doesn’t matter what you temperature rating is. Loft is the key. Loft is how “poofy” the bag is. If you want to know the loft leave you bag out for awhile and then measure it from the ground up with a ruler.
Loft is the term for how thick a bag is.
Loft only really matters on the top of the bag as the bottom will be squished.
Loft is loft regardless of the material (of course some exceptions)
2” of down is the same as 2” of newspaper (weight and density will change).
General rules that will differ according to metabolism.
2.5” is equal to about 0 degrees
1.5” equals about 40 degrees
8” is good to about -60
The relationship between loft and warmth is not linear
Tips
Make sure you have calories in your body to burn.
My wife keeps a bag of Hersheys kisses next to her bag when winter camping and pops one in her mouth every couple of hours to add some calories to the system.
Change you clothes, socks, underwear, headgear, everything before you get into your bag.
Nakedness does not equal warmth in you bag that is an old wives tale. This comes from old guys climbing into their bags with wet cotton long johns on. Of course you will be cold.
Sleep socks are awesome, but need to be loose fitting.
You need to be sleeping on a pad. Thermal heat transfer occurs significantly fast with conduction than convection. You pad is MORE important than your bag. (Article on pads forthcoming)
Cover your head.
Vapor barriers can greatly increase your bags warmth, but some feel icky when sleeping in one.
You need to stop heat transfer. You never get cold, you get less warm. Heat moves from hot to cold not the other way.
The types of heat loss are conductive, convective, evaporative, radiative. Slow these down and you will be warm.
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