How to choose the right sleeping bag?

Published on: 2019-04-26

Author: iza

Good sleep is fundamental to our well-being. When we spend the night away from home, rest largely depends on the sleeping bag we choose. How to choose a sleeping bag that will meet our expectations and will serve us for years?

First of all - the sleeping bag should be selected in terms of the activity we are doing . You need different sleeping bags for camping with the family, another one for a mountaineering trip.

Sleeping bags for various occasions

If you usually sleep indoors and you are not threatened with temperatures lower than 15-20 degrees Celsius or high air humidity, lightweight materials that easily reduce their volume will work better. The sleeping bag does not take up the entire backpack then. An example is the Core line of the Polish manufacturer of expedition clothing and equipment - Pajak Sport.

When you plan a long route and sleep under the stars , the drying speed of the material and its resistance to moisture will be important. However, you should take a good look at the weight to heat ratio that the product offers.

Also, pay attention to when you go on expeditions most often. If it's summer, you probably don't need the warmest possible version of a sleeping bag. Of course, this does not apply to lovers of high mountain expeditions to the Alps or the Himalayas.

What to choose when you go camping once and explore a cave another time? Well, you might find you need two different sleeping bags, possibly a hybrid version.

The first factor - temperature

When choosing a sleeping bag, we usually pay attention to the temperature for which it is intended. However, you should be careful, because only some of the products available on our market are certified by independent testing laboratories in accordance with the currently valid ISO 23537-1: 2016 standard (formerly EN 13537: 2012 and EN 13537: 2004). Therefore, many manufacturers do not use this method, and instead provide temperatures based on their own findings that are difficult to verify.

Usually (as well as according to the standard) three ranges are given:

Comfort Temperature - Female comfort, the lowest temperature at which the average woman feels good and warm.

Limit Temperature - Male comfort, the lowest temperature at which the average male feels warm. At this temperature, a woman may already feel cold, making it impossible to sleep comfortably.

Extreme temperature - the lowest temperature that does not threaten our life or health.

Sometimes I also mention the so-called " upper limit" . This is the temperature above which it is too hot in the sleeping bag.

Using the above-mentioned standard, measurements are carried out using a special dummy. The role model is a man with a standard body build (25 years, height 173 cm, weight 73 kg) and a woman (25 years, height 160 cm, weight 60 kg).

Remember that each of us feels the temperature very individually . The difference between the sexes alone in the worst-case scenario gives us 9 degrees of difference (women freeze faster), and the jump between 20 and 29 degrees Celsius in perceived temperature below zero is enormous. So it's better not to buy one sleeping bag for two.

In addition, the perceived temperature is influenced by the insulation on which we sleep (a regular sleeping mat or a good mattress), the type of meal before bed, our mental condition - including the degree of fatigue and, of course, our outfit . Air humidity will also have a significant impact on the perception of temperatures.

However, there is one very simple criterion that will make it possible to evaluate the sleeping bag even to someone who is not very familiar with the subject. This criterion is the height of the sleeping bag when lying down, depending on the quality of the filling (loft) used. A sleeping bag that has a larger loft will usually be warmer. The only situation when the rule does not work is the use of specific construction solutions, such as, for example, a layer reflecting infrared radiation.

Type of filling

Down or synthetic filling? Down sleeping bags are perfect for cold, dry conditions , but they are not the best choice when you expect liquid water, because wet down will temporarily lose its loft and therefore will not insulate. Sleeping bags with impregnated down (hydrophobic) are more resistant to water.

Unfortunately, the lower the temperatures, the smaller the choice of thermal insulation available. If we are going to use the sleeping bag mainly in winter conditions, the only thing left to do is to choose only natural down .

What really warms us is not the amount or weight of the filling, but the volume of air , which is a great insulator, provided that it remains stationary or its movement is significantly limited.

When selecting a down sleeping bag, pay attention to the elasticity of the filling (cuin - "cubic inch"), which determines how many cubic inches there are in an ounce of down in a standard measuring cylinder. Down is subjected to a load of one ounce (~ 28 g). The higher the parameter, the better (fluff with higher elasticity will better retain heat at the same weight, is also more susceptible to compression), but 700 cuin (cubic inch) is considered very good.

Duck or goose down? When it comes to parameters, white Koluda goose down is unrivaled and can be found in the top models of the world's best brands. It is also used by all domestic manufacturers, e.g. in Pajak Radical or Prime sleeping bags. Kaczy is a cheaper and, unfortunately, less perfect raw material, but both of them significantly exceed the parameters of synthetic insulation.

Artificial down (of the best quality) gives us more or less the same protection as down with an expansion of 500-650 cuin. Duck down reaches expansion levels from 400 up to just over 700 cuin. Goose down gives us parameters from 650 cuin up to 1000 cuin. If the expansion is not given, it is usually the worst version of the natural raw material.

The general rule is that the wetter the environment in which we use the purchased product, the more we should pay attention to synthetic warming. Synthetics dry quickly and do not cease to insulate even when wet.

They are also a good solution when we use them in warm conditions and when we do not count every gram or centimeter in the backpack (they have worse compression). They also have the undoubted advantage that they are usually cheaper than down sleeping bags. When we decide on them, remember that, just like in the case of down, the higher the loft, the better.

Construction of chambers

The equipment made of down uses 5 basic constructions:

quilted chambers / longitudinal sewing - this allows you to create the lightest product, but due to thermal bridges in the stitching places, the product's thermals drop significantly.
T / H chambers - are the most common solution due to material economy and relative simplicity of sewing. The use of such a structure significantly reduces thermal bridges.
Z / S chambers - this is a better type of T-chambers thanks to the shifting of the upper and lower fabrics in relation to each other. The stitching places are not located directly next to each other, which eliminates thermal bridges. This construction allows for a much lower weight than in the case of V (or trapezoidal) chambers, while providing similar insulation.
trapezoidal chambers - are a variation of Z chambers, where individual partitions are alternately inclined one way and the other, allowing the use of this solution in clothing. This solution is also used in very warm sleeping bags, as it is cheaper than double H.
HH chambers - the warmest solution used only in several dozen products in the world, e.g. in Radical H16 IRR by Pajak . In this construction, an offset is applied between the two layers of the walls of the chambers. It is thanks to this solution that the Pajak company received the award for the warmest sleeping bag in the world at the ISPO fair in Munich!

Fabric

Sleeping bags are made of polyester, polyamide (nylon) and polyamide 6.6 (eg Cordura). It is worth choosing the best possible fiber, i.e. polyamide 6.6 , then polyamide / nylon and finally, the weakest of them, polyester.

Another issue is protection against moisture. Almost all fabrics used in sleeping bags have a DWR coating, but not all have a built-in membrane .

Its use is to protect the user against water that can enter from the outside . Thanks to this, we can spread the sleeping bag in a puddle and nothing will happen. This solution, however, costs many times less breathability than the same fabric without a membrane. Water that comes from ourselves, that is our sweat, is a huge problem. Over half a liter of water evaporates from the surface of our skin during the night! Water vapor passing through successive layers condenses at the point of the greatest temperature difference, i.e. on the inner side of the outer fabric.

The use of a waterproof membrane or fabric will work mainly in very short one or two-night trips.

Another solution is to focus on protecting the user from the water he emits himself . In this case, the constructor's efforts are focused on ensuring that each successive layer is more vapor-permeable than the previous one. Thus, each night in the sleeping bag will be just as warm as the first. The disadvantage of this solution is the need to use a waterproof tent or camping cloth. Membrane-free, non-waterproof fabrics will be more suitable for long-term expeditions .

Hybrid solutions

It happens that existing products do not meet our needs separately. Then you need to use a hybrid solution, which consists in the use of two compatible sleeping bags. The outer layer is a waterproof summer synthetic sleeping bag , while the inner layer is a winter ultra-light down sleeping bag . Thanks to this, the condensation of water vapor, if it occurs, will soak the synthetic part, leaving the down part in perfect condition. The advantage is significantly lower weight than a purely synthetic solution ensuring comfort in the same thermal conditions.

This solution works perfectly where:

there are very field conditions (bushcraft, survival),
we operate in wet environments (caves, shipping),
we have a limited budget, and we need a sleeping bag that works well with large temperature fluctuations.

Summary

What do we finally need to determine before buying? First of all, what temperatures will we spend the night in, how long the trip will be, what is the risk of getting the sleeping bag wet. If we have already carried out outdoor trips, it is worth remembering the conditions that have prevailed on them over the last 5 years and compare them with those that we expect on the next trip.

Depending on the factor that is of paramount importance to us, the choice will be different.

Due to the conditions:

Caves, other wet environments - synthetic warming
Extremely low temperatures - natural down
When you want ultra-light weight - natural down
When volume matters - natural down

Check that the temperatures are given in accordance with EN 13537 or ISO 23537.

If not, compare loft ("thickness of sleeping bag")
If so, compare temperatures

Decide how you will use the product:

short service life and wet environment - look for membranes
long-term use - avoid membranes (but put on a good tent)

If you can, choose the perfect fabric:

preferably polyamide 6.6
not too bad polyamide / nylon
as a last resort - polyester

Remember, there is no perfect product . You can have the warmest, the most waterproof or the lightest sleeping bag. The most important thing is to choose the product best suited to the specifics of your outdoor activity.

The text was created thanks to consultation with Wojtek Kłapcia from Pajak Sport .