What makes a great sleeping bag for a canoe trip?
Sleeping bags are filled with either natural down or synthetic materials. Synthetic materials vary widely by manufacturer, but all serve as less expensive, heavier alternatives to down. Their great benefit is that they insulate even when wet, so if your tent floods or your canoe swamps you will still be warm, if soggy. Down’s advantages are that it is highly compressible and light-weight. Also, when well-cared for, down can last for 20 years without losing its insulating properties, while synthetic materials degrade even after 5 years.
What does the “comfort rating” on sleeping bags really mean? It’s a way for the manufacturer to indicate the coldest temperature at which a sleeping bag will keep you warm. But think of it as a guideline instead of a hard and fast rule. There are no industry standards to regulate these ratings; two bags with the same rating might not be equally warm. Plus, everyone sleeps differently. If you’re a cold sleeper, look for a bag rated about 5 -10° colder than the lowest temps you expect. And remember, lower ratings usually mean heavier bags. A sleeping bag is an insulator that keeps you warm by trapping the heat that your body generates. So, if you are a cold sleeper and don’t generate much heat at night, you may need a bag with more insulation. Similarly, if your body easily overheats, choose a bag given a warmer comfort rating.
Most sleeping bags come in three shapes: mummy, semi-rectangular, or rectangular.
|A mummy bag is the most-efficient shape, and may or may not have a hood. The hood and narrow neck opening prevent heat loss, while the tapered fit limits the amount of extra space you need to warm with your body heat. Some folks find mummy bags constricting, however, and thus prefer a semi-rectangular bag.|
|Semi-rectangular bags, again, may or may not have a hood. They are roomier than mummy bags, while still fitting fairly close to the body.|
|Rectangular bags are the roomiest of all, with lots of space in the hips and feet. They do not feature hoods at the top. They are bulkier than most mummy or semi-rectangular bags, and will not keep you as warm because of the extra space and opening at the top. That said, if you prefer the extra space and don’t have to worry about cold weather camping, rectangular bags are your best choice.|
All three shapes will usually zip together, but mummy and semi-rectangular bags require that one of the zippers be on the left side and the other on the right. Because the top and bottom of rectangular bags are typically identical, you can simply flip one of these bags over to create the necessary zipper combination.
As you sleep, your body radiates heat and a good sleeping bag traps this heat in the dead air between you and the bag. If a bag is too big, you aren’t able to generate enough heat to warm up all that space. Many bags come in multiple lengths, so look for the size that is a bit longer than you are, but certainly not too short. When comparing two bags, you can also look at the measurements for girth at the hips and the shoulders to see what most closely matches your body frame.
Women’s Sleeping Bags:
Bags made specifically for women have different proportions than unisex bags: 5′ 6″ long, narrower shoulders, and wider hips. They also tend to have increased insulation in the torso and the foot box, because a woman’s body actually shuts down circulation to the extremities sooner than a man’s. Make sure to check the features and specifications for the individual bags and manufacturers that interest you.
Down Fill Power:
Synthetic sleeping bags vary by what material is actually used to fill the bag, but down varies based on its quality, or what is called its fill power. Higher quality down is denominated by a higher number. Basically, when the down is higher quality, you need less of it to stay warm, because higher quality down lofts up more and traps more air, and the amount of air around you is what actually does the insulating. Most sleeping bags contain down between 600 and 850 fill power. This number is the number of cubic inches that one ounce of this down will fill. So, one ounce of 600 fill down will fill 600 cubic inches, or, a cube with sides 8.43 inches long. One ounce of 850 fill down will fill 850 cubic inches, or, a cube with sides 9.47 inches long.
In essence, the same quantity (one ounce) of down, fills up a bigger space, traps more air, and keeps you warmer, so you don’t need as much of it, and you can have a lighter, smaller, equally warm sleeping bag. This means you need less 850 fill down than 600 fill down to fill up the same space, so 850 fill sleeping bags are lighter weight. Of course, then, the 850 fill sleeping bag is more expensive, because it contains down of a higher quality.
Every manufacturer makes their sleeping bags a little bit differently, so for specific features check the information that they provide. Openings around the head and shoulders or stitching that penetrates every layer can leak warm air and leave you shivering through the night. Insulation shifts inside the bag, so you want to look for baffling (tubes) or quilting (squares) that will keep the fill, whether it’s down or synthetic, from bunching unevenly. A collar at the top of the bag can prevent heat from escaping around your neck, while a draft tube can prevent heat from escaping out the zipper. Some bags have differing layers of insulation on the top and bottom. If you’re a cold sleeper or don’t own a sleeping pad, losing a few extra ounces on the bottom of your bag may mean losing a few degrees of comfort as well.
Store your bag loose in a large cotton sack. Do not store it in a plastic bag, as moisture can accumulate and damage the materials. Do not store your bag compressed, because over time it can crush the fibers or down so that they lose their loft (their ability to puff up and trap air), which is what keeps you warm.
Unstuff your sleeping bag when you get to camp. Allowing the bag to loft for at least an hour before you get in will allow the bag to maximize its space, and thus its insulating capacity.
It is also a good idea to sleep on a sleeping pad. Pads provide important insulation between you and the ground, not to mention padding, that keeps you warm and comfortable through the night.
Before going to bed, doing some mild activity and eating long-burning carbohydrates will help you generate heat initially and then throughout the night.
Sleep in the right combination of clothes for the weather conditions at the time. Over-dressing can lead to perspiration, and once wet, your clothes and bag will keep you more cold than warm. Likewise, under-dressing can mean that you don’t have enough insulation to generate the heat you need to warm your bag. Some folks prefer to sleep naked, but it’s not an absolute requirement in order to be comfortable in your bag.