According to the European standard in 13537 on requirements for sleeping bags, all the sleeping bags marketed in the European Union must show its labelling 3 temperatures: the “extreme temperatures”, “temperature limit of comfort” and “comfort temperature”.
The “extreme temperature ” is one to which a standard woman who is shaking to increase its production of metabolic and in the fetal position to reduce heat losses, can hold up to 6 hours in the sack before going into hypothermia.”
The “limit of comfort temperature” is what allows a standard man in the fetal position inside the bag retain its thermal equilibrium and not feel cold.
The “comfort temperature” is the one to which a standard woman in a posture relaxed into the sack won’t neither cold nor hot. All these temperatures of sleeping bags are calculated according to Sleepingbagsexpo: in a laboratory without wind and with a humidity between 40% and 80% is placed a mannequin dressed in a full suit in two parts and socks into the sack-proof, and this in turn is available on a mat that rests on a 12 mm thick wooden board. Since outdoor conditions are not always so ideal and above all vary rapidly, it is advisable to buy the bag taking “temperature limit of comfort” as the lowest anticipate that we can get to sleep. This choice gives us a margin of acceptable security contingency so common in the world of the mountain.
The filling quality
It is specified by two numbers which indicate the proportion by weight of down (duvet) (1st digit) regarding the small feathers (2nd digit) grooming. 90/10 means 90% down and 10% Feather. The quality of the filling along with the weight or total weight of the feather, facilitates proper insulation.
What are the Cuin?
Los ‘cuin’ (cubic inches or cubic inches) are the unit used to measure the ‘Fill Power’ which is the ability of inflation down.
How to measure the Fill Power? You take one ounce (28.35 g) of down to try and is placed inside a transparent calibrated cylinder. Stops down to swell to its maximum capacity, are placed over a cover of 67.2 g 60 seconds to put pressure and volume that is set down in the scale of the cylinder is measured. The greater the number of ‘Cuins’, greater is the power of inflation and the insulating capacity of the marker. To greater filling power superior thermal insulation, the power of various padding between 400 and 850 cuin.
How to choose a sleeping bag down?
The first thing is to know the quality of the marker containing the sack. They should include the quality and power of swollen (Fill power) of down. The mixture must contain a minimum of 80-90% of real down: how much less better wings. The power of inflation (insulation) of down is expressed in ‘Cuin’ (cubic inches) and more better!.