What did the EN 13537 standard sets? :
This legislation sets out a method to measure the levels of temperature of a sleeping bag on the basis of a thermal test performed on a mannequin and subdivided into 20 sectors for which different temperatures are measured separately. Depending on the values for the various sectors and the climate chamber temperature, determined overall 4 values of temperatures that are reported on the labels of all the sleeping bags and for which we provide the following definitions.
Maximum temperature: this is the maximum temperature level at which a men’s average weight (80 Kg) can spend the night in comfortable conditions and without breaking a sweat.
Comfort temperature: this is the temperature level at which a women’s medium build (60 Kg) can spend the night in comfortable conditions.
Temperature limit: this is the minimum temperature at which a male medium build (80 Kg) can spend a night in comfortable conditions.
Extreme temperature: this corresponds to the temperature level at which a medium build can spend a night without physical damage
Important: The thermal properties data are laboratory values; in practice, sensitivity to hot and cold depending on people and may in all cases be influenced by factors such as the level of fatigue, hunger, or morale.
Remains also to compare sleeping bags, the standard of the “fill power”. Usually located between 500 and 900 the fill power is the quality of the down snowflake… more it is thin and has strands, more down will be lightweight, compressible and will have a great power of heat retention. Conversely, more down Snowflake is big with little strands, close to the snowflake, it will be heavy, a little less compressible and it will take a lot more to have a good power to heat retention. For example 100 grams of down with a fill power of 900 has the same power to heat than 400 g with a fill power of 500! So why not put the 900 everywhere? Simply, optimum quality is obtained at the end of the process of selection of down… and is where there is the least, it becomes so much more expensive!This is how you can find sleeping bags with flannel choosing tips that are lighter and thinner but better than another bag to look thicker appearance… A little trick to quickly describe the good power of a sleeping bag down…Compress a part of the bag in hand and release… watch how fast the bag found annoying sound!
2 Temperatures are mentioned: comfort and extreme. The comfort temperature is the nominal use of the sleeping bag area, it’s the temperature area where it will not feel cold and where there will be enough heat to a good night. Below this temperature comfort and based on your experiences to the cold, we can start to feel an evil be the night freshness which will be all the more important that we approach the extreme temperature of the bag. It is good to know that a bag is never too hot, you can always air via the zip, a bag, however, may not be enough insulation.
The extreme Temperature a bag should never be exceeded. It is actually the reference limit security for the survival of the organism, underneath there is danger sometimes see mortal danger. The feeling of cold is felt long before reaching this limit, therefore the best is to rely on the comfort temperature for the choice of your sleeping bag.