The choice of a sleeping bag is a search of a reasonable compromise between the following parameters:
- Temperature condition;
- The used heater;
- Weight and volume;
How is the recommended temperature range of operation of a sleeping bag defined? What is the EN 13537 standard?
Compliance of a sleeping bag to estimated temperature range of its operation – the primary parameter at the choice.
Temperature condition of the majority of the sleeping bags sold today defined by testing which regulations described in the EN 13537:2012 standard. For tests, the thermo-dummy which models a thermal emission of the “average” man (25 years old, height – 173 cm, weight – 70 kg) and the “average” woman ( 25 years old, height – 160 cm, weight – 60 kg) used. According to a technique of testing, it supposed that sleeping the set of a layered clothing and socks use. According to regulations, the tested sleeping bag completely zipped, and the hood is put on and correctly tightened.
Following the results of tests the temperature range consisting of 4 values appropriated to a sleeping bag:
- T, max – the top extreme air temperature at which the “average” man comfortably sleeps in a relaxed pose without feelings of cold and considerable sweating. This value is not obligatory to the publication the producer of a sleeping bag since does not influence the safety of life and health of the person. During the determination of parameter T, max the sleeping bag during the test can be clasped not up to the end.
- T, comfort – a temperature at which the “average” female user comfortably sleeps within at least 8 hours in a relaxed pose. This value is obligatory to the publication on a label of a sleeping bag. A range between temperatures of T, max and T, comfort conditionally is called “a zone of female comfort”.
- T, limit or “the lower limit of comfort” – the air temperature at which the “average” male user comfortably sleeps within at least 8 hours in the pose interfering loss of heat (having been curtailed and having drawn in knees). This value is obligatory to the publication the producer of a sleeping bag. If only one value from all temperature range of the EN 13537 test specified in the catalogue, then it is T, Limit since it characterises limit service conditions under which the sleeping bag can provide a safe dream.
- T, extreme – designates temperature border at which there is a risk of overcooling capable of doing serious harm to the health of sleeping. At this temperature, the “average” female user is capable of sleeping 6 hours in a pose to the interfering loss of heat. At the same time, the shiver which increases metabolism and allocation by heat body not excluded. About a comfortable dream at the same time the speech does not go – at such temperature repeated awakenings because of feelings of cold are possible. Value T, extremely is obligatory to the publication on labels of the sleeping bags which passed the EN 13537 test.
How to use these EN testings at the choice of a sleeping bag?
That the dream in a sleeping bag was comfortable follow the following rules:
- At the choice be never guided by a temperature of “extreme”. The test centre gave it for a definition of an extremely low border at which the sleeping bag provides a little acceptable thermal insulation. The risk for life accompanies the use of a bag at a temperature below this threshold. In some situations, for example, for an economy of a weight of equipment, the sleeping bag can be used in “an extreme zone”. But it is a prerogative of the tempered and well-trained athletes who sometimes use a sleeping bag in combination with outerwear; it is frequent during only 1-2 spending the night.
- Sometimes value T, a limit is considered as use temperature “recommended” by the producer. In practice, will sleep comfortably at such temperature to only rather skilled and physically tempered tourists, capable of picking up the clothes set corresponding to weather conditions for a dream. Inexperienced users, using a sleeping bag on a border of “the lower limit of comfort” can feel discomfort because of cold. Also, people can be guided by value T, limit with a large constitution. They generate more heat which holds a sleeping bag.
- Be guided by choice of a sleeping bag by value T, Comfort if you poorly transfer cold, and quickly you freeze, you do not differ in a strong constitution, and you have no solid tourist experience.
Remember that laboratory testing does not consider many factors from real marching practice. It is carried out indoors, deprived of a draft or wind. Conditions of the test assume sleeping they did not get wet, are not hungry, do not experience overcooling and overfatigue. New sleeping bags which did not lose the properties in the course of wear provided for the test. Realities of a campaign can push off you with the listed problems therefore well think before buying the sleeping bag standing on the border of the range of temperatures of use assumed by you. Sometimes it is more expedient to get a sleeping bag with small “stock” on thermal insulation.
It is possible to move apart borders of comfortable temperature range – having applied, for example, a combination of two sleeping bags. So, skilled climbers sometimes use two sleeping bags in one expedition. The first – easy and thin, is involved on approaches, at small heights. The second – warm, is used in intermediate camps at Ascension. If a comfortable sleeping bag to enclose in warm, the tandem which maintains extremely cold conditions with which there is a risk to face at big heights turns out. The matter is that between an internal and external sleeping bag there is an additional air layer which significantly increases the general thermal insulation.
If you go hiking not one, to use two identical sleeping bags with the versatile provision of lightning which can be clasped in one 2-seater sleeping bag. Will sleep together in one bag much more warmly, than one by one in different.
Conditions of the EN test do not give reliable values, and the temperature borders outlined by it have errors. Therefore if according to the test one of sleeping bags is “warmer” than the competitor on 2-4 °C, not always it is shown in actual practice operation.
The feeling of heat and cold very individually at each person can also change depending on the extent of acclimatisation, psychological state and other factors. Therefore these EN testings should be considered at the choice as an approximate reference point.
The test according to the EN 13537 standard is the expensive procedure and has advisory nature. For this reason, many producers will not see it. First of all, it concerns small brands, for example, of the known Z-Packs. But there are among them both such large and authoritative producers as Mammut and Therm-a-Rest. In spite of the fact that their sleeping bags do not take the EN test, the temperature values specified on labels have the same form of record. The top and lower limits of comfort and “an extreme zone” are indicated them. Producers obtain this information carrying out own tests and also using calculations by those data that received at EN testing of similar sleeping bags at competitors.
What are sleeping bags not obliged to take a test according to the EN 13537 standard?
- Sleeping bags for kids and children of younger age. The test centres cannot simulate on a dummy a thermal emission of the sleeping child during sleep in a sleeping bag at low temperatures since for ethical reasons of test for a perception of cold were not carried out on real children.
- Sleeping bags for the military since requirements of armed forces of the different countries to the used regimentals and rugs strongly differ and can significantly differ from those that are used according to regulations of the EN13537 standard.
- Sleeping bags with a temperature of comfortable dream below -24 °C. Extremely low temperatures can assume a dream in a sleeping bag in the warmed clothes. It is not possible to simulate such conditions within the standard test. On labels of the sleeping bags intended for extremely low temperatures temperature of the lower limit of comfort is specified. It pays off producers independently by a thermal capacity of a heater, and its weight then is confirmed by natural tests.
Non-standard sleeping bags. It is about 2-seater models and sleeping bags without a hood.
With what heater to choose a sleeping bag?
Many copies are broken on a field of disputes on what heater in a sleeping bag the best – synthetic or natural down.
So that also you had not to plunge into depths of these discussions and to simplify a choice process, we will outline zones of effective use of down and “synthetics” which settled in the last decade of development of the world industry of sleeping bags.
When is it worth giving preference to a down sleeping bag?
Down – the undisputed leader in the ratio “weight/heat” which defined by an indicator of Fill PowerFill Power – a measure of a quality of down which defines the ability of a heater to be restored after compression. The Fill Power indicator is higher; the product is warmer with the same mass of down. High-quality down – feathers mixes which give in sleeping bags real advantage before modern synthetic heaters possess F.P indicator. 750 and more. The thermal insulation provided by them with a small weight, predetermined domination of down in the following conditions:
- In sleeping bags for extremely low temperatures with a temperature of a comfortable dream of close or below -24 °C which polar explorers, high-rise climbers, hunters, fans of winter tourism and so forth use. For such cold conditions there are bags and from synthetic heaters, but they more in packing volume is incomparable (sometimes by 2-3 times) and it is much heavier.
- In combination with fine fabrics and a laconic design down is used in a production of Sleeping bags ultralight – class. Here high ability of a down heater to a compression is not less important. The compressed ultralight – a sleeping bag is very compact and occupies volume in 2-3 litres. This property made extra light down sleeping bags popular not only in the environment of the easy courses, pedestrian and bicycle tourists but also among kayaker.
Producers constantly fight against the main lack of down as heater – fear of moisture. Today even more often it is processed hydrophobic impregnation and use the materials which are not absorbing moisture as a fabric cover. They do not solve a problem for 100%, however, so the down sleeping bag remains dry in a campaign much longer.
When is it worth choosing a sleeping bag with a synthetic heater?
In effect – for all above undescribed situations. Producers and users are imposed by unpretentiousness and a cost of synthetic heaters, in particular against the background of world increase in prices for down. “Synthetics” is capable of keeping the most of the volume when moistening, almost without changing the heat-insulating properties. At the same time, such heaters quickly dry – very important positive property since in a campaign of time and conditions on drying of a sleeping bag can almost not be. In recent years there was a set of synthetic heaters which possess a good ratio “weight/heat” and at the same time are compact in packing. All listed properties predetermined domination of synthetic heaters in:
- Kemping and budgetary tourist sleeping bags – for a low cost.
- Tourist sleeping bags for 3-seasonal operation – for moisture resistance and the general unpretentiousness. On mountain and tourist routes you can spend one night in snow on the pass, and be following – already in the warm valley on the river bank. It is much simpler to cope with such difference of temperatures and humidity of synthetics, than down.
- In some models of winter sleeping bags which are applied at serious differences of temperatures which are followed by the increased humidity. Such conditions can be frequent in mountaineering, and also during hikes at the beginning of spring.
Sometimes producers combine in one sleeping bag two types of heaters at once. So, for example, Sivera Shaush-9 sleeping bag bottom is filled by a synthetic heater of ClimaShield Apex which reduces heat losses from a back since it is less rumpled. And its top and sides are warmed by high-quality down with F.P. 800+.
Any of the heaters applied today is not eternal. Any sleeping bag over time loses volume and ceases to hold air so effectively as new. Therefore the term of active operation of a sleeping bag depends on the durability of a heater also.
In this regard down much surpasses the existing synthetic heaters, but under one condition – the sleeping bag should not be exposed to a regular compression in the raw. It is capable “to kill” a down heater literally for a couple of seasons. Alas, but it is never impossible to subject down to compression in a damp state in real marching practice. Nevertheless down sleeping bags serve inaccurate hands without loss of properties much longer, than their fellows with synthetic heaters.
The correct storage will help to prolong life to a sleeping bag. Carefully you dry a sleeping bag after a campaign. You do not store it in summary form – in a compression bag or a vacuum package. It is better to use for this purpose a volume packing bag, to hang up a sleeping bag on a hanger or to accurately put it on the shelf or in a furniture niche.
Weight and volume of a sleeping bag
The low weight of equipment always promises to the important tourist advantage – with an easy backpack to move ahead along the route much more simply. However, the weight of a sleeping bag cannot be estimated in a separation from its heat-insulating properties, and also a form and the size. If the sleeping bag is much easier than the analogues, pay attention to what measures the producer went to achieve it and how it will be reflected in comfort of your dream?
So, for example, developers can lose the weight of a sleeping bag without loss of the heat-insulating properties having reduced quantity of the used heater on a back where it is all the same rumpled, and the rug is responsible for thermal insulation. However, such approach does a dream on one side uncomfortable – the user’s back quickly cools down, leading to awakenings.
Its volume also is closely connected with the weight of a sleeping bag, the sleeping bag; the more compact it in packing is easier. The small volume of a sleeping bag promises the user only pluses since this subject of equipment the most large-size of all camp equipment and “eats” a considerable share of space in a backpack.
Selection of the size of a sleeping bag
At the choice of the size of a sleeping bag, it is important to observe balance. A Too small sleeping bag will be close, and the heater compressed in shoulders will not possess effective thermal insulation. In too big sites which do not get the warm heat of your body are formed.
Usually, the size of a sleeping bag is determined by the principle “growth of the user + 20-30 cm”. Such bag will not be close and will allow using an insert or a set of fleece clothes as additional warming. With a serious stock by the size, it is possible to get only sleeping bags for winter operation since in them it is necessary to place batteries, a small lamp, inserts from boots and other things which surely have to remain in heat and dryness. Also in hot sleeping bags, the possibility of a dream in the top warmed clothes is often put for what in their cut the additional space is put.
Anyway, before purchase, it is desirable to try on a sleeping bag. Lie down in it, try to zip and tighten a hood to estimate ergonomics and compliance of a sleeping bag to your dimensions.
For people with very large constitution sleeping bags of the increased size – for example, Marmot Trestles Long X-Wide are issued. Also in an assortment of the producer models for women and children can be presented. On the example of Marmot – Trestles Women’s and Trestles Kids. Besides the smaller size, they possess bigger thermal insulation, than usual “unisex” – the version.
What form to choose: cocoon or blanket?
Basic forms exist two – a cocoon and a blanket. Sleeping bags blankets have a rectangular shape and a full lightning on two parties which allow to undo them and to turn into a cover. This property made them very popular for use in campings, at dachas and even at home. On the other hand – the rectangular shape leaves many cold zones which are not warmed by your body in a sleeping bag and do a sleeping bag heavier.
Sleeping bags cocoons have the form which is narrowed to legs repeating a contour of a human body. Thanks to it they are warmer and easier than the rectangular fellows that made a cocoon a traditional form for a tourist sleeping bag. At the same time, a variety of sleeping bags cocoons is very big, and among them, there are wide and comfortable models suitable for use both in campings and in tourism.
Directly depends on functionality, technical features and the size of a sleeping bag. Therefore, the most expensive in all industry are down sleeping bags for extremely low temperatures. Very large volume of an expensive heater and fabrics, a difficult pattern with a large number of details which will interfere with losses of heat and the considerable size that the user could put on an additional layer of clothes is necessary for them.
Forming the budget on the future sleeping bag do not forget about a need for purchase of the tourist rug suitable for it, especially if it is about a bag which will be used at negative temperatures.
Rug role in a comfortable dream
Let’s remind that a sleeping bag – only a component of your sleeping system. Its second component is the tourist rug, and your thermal comfort depends on during sleep on its correct choice. Selection of a rug is important also because in a back the heater of a sleeping bag is crumpled by the user and does not provide due to thermal insulation.