Low temperatures of winter campaigns, polar expeditions and high-rise mountaineering force producers to work fairly in a development of warm sleeping bags. Eloquently says the fact that not all famous brands of outdoor equipment have in the assortment the sleeping bags suitable for use in really serious frost about complexity and a high cost of this process.
What distinguishes the warmest sleeping bags from all others and where, according to testers and producers, “the severe frost” begins?
According to the EN 13537 standard, for extremely low temperatures carry models to sleeping bags with the lower temperature of the comfort of -24 °C and below. Let’s remind that according to regulations of the test it is a limit at which the comfortable dream within 8 hours for the “average” man is still possible (25 years, height of 173 cm, the weight of 70 kg). The sleeping bags which reached such indicator are not subject to obligatory check. In practice, the producer of a sleeping bag nevertheless can test it, but the received temperature condition is true much less. On compliance with the EN 13537 standard since laboratory conditions cannot precisely reproduce real conditions of their operation.
Producers independently test own sleeping bags and then determine the recommended temperature range. It is natural since test techniques of the different companies can strongly differ, and real thermal insulation at them can differ considerably. It also depends on the mass of the used down, and on a complexity of a design of the sleeping bag. As a rule, producers specify only one value which is tried to be brought closer to the lower temperature of the comfort of the EN 13537 test.
For whom so warm sleeping bags are created?
First of all – for “climbers-spidermen” Make ascensions on tops over 6 500 meters high above sea level. And participants of polar campaigns and expeditions. Both those and others face nearly most ruthless climatic conditions on the planet among which cold is the most dangerous enemy. High-rise climbers and polar explorers overcome very heartrending physical experiences – they are inevitably expected wearisome work on a route, by the large volume of wearable equipment, lack of the laid tracks and so forth. Such loading is aggravated not only by weather, but also dehydration, and in a case with Highlands, oxygen starvation is added to it. All these factors lead to an aggravation of cold sense which aggravated at a decrease in heat production of the person during sleep. In such conditions, hot sleeping bag not just gives an opportunity to sleep well. It is a guarantee of survival.
Certainly, the circle of users of especially warm sleeping bags is not limited only to climbers and participants of campaigns in the Polar region. All who by the nature of the work or hobbies face needing to sleep in a strong cold – hunters, fishers, pilots of the Arctic aircraft, geologists, military, fans of winter campaigns enter it. This list can be continued very long.
Developers of sleeping bags for extremely low temperatures realise the high responsibility for the health of users and make all efforts to achieve the maximum thermal insulation from the products. Sometimes even the total weight of a sleeping bag has pushed the background, despite the fanatical aspiration of modern designers to facilitate equipment in that that became. At the same time, the advanced materials and technologies do the part. Today hot sleeping bags which weight keeps within 2 kg that much easier many budgetary 3-seasonal models are presented at the market many.
What sleeping bags for extremely low temperatures from other presented in the market differ?
- In most cases, high-quality goose down acts as a heater. Only it is capable of providing necessary thermal insulation within the acceptable weight and packing volume of the future sleeping bag.
- All design works on the preservation of heat. Developers try not to allow formations of “cold points”. Therefore through seams and the differentiated warming are not used – when the bottom of a sleeping bag jams down less, than top and sides. At the expense of a difficult design of down packages migration of a heater is minimised. The lightning is without fail covered with the thick warming level, and a warm adjustable collar surrounds the neck of sleeping. The hood is obliged to be dragged away densely on the user’s head too, leaving open only a small crack for breath. At the same time, its design is most often much more complicated, than at 3-seasonal models to avoid migration of a heater.
- Sleeping bags for extremely low temperatures possess a cut which allows using as additional warming outerwear, for example, a down jacket or overalls. Also, spacious sleeping bag allows placing in itself all equipment which it is undesirable to leave on cold – accumulators, electronics, inserts from double boots or a gas cylinder. Sleeping bags for especially low temperatures differ in high “Weatherproof”. A practice of their use does not exclude cold spending the night. Spending the night out of the prepared shelter – a full-fledged snow cave, a tent or a mountain shelter., especially at high-rise ascensions. Also at spending the night in shelters, mountain huts and tents there is a risk of loss of plentiful condensate on an outer side of a sleeping bag. Therefore that moisture from thawed snow and perspiration was not absorbed and did not moisten a heater, lowering its thermal insulation, an external fabric of sleeping bags is processed water-repellent structures, and also use membrane materials.
- Alas, but limited demand, a complexity of design, the down and need of comprehensive quality control which from year to year is rising in price leads to the fact that sleeping bags for extremely low temperatures differ in high price. But high cost inherent in them also has a positive side – designers can test the materials which were earlier not applied because of high cost and technologies of tailoring, having provided to the user technically more advanced product.
Sleeping bags of The North Face Inferno-29/-40
The Inferno series is one of the most known and popular sleeping bags for extremely low temperatures in the market. The successful design tested not only athletes of The North Face, but also a great number of the “ordinary” climbers submitting the highest peaks of the planet. All sleeping bags of Inferno enter the Summit Series collection which unites in itself the advanced clothes and equipment for mountaineering and technically complex mountaineering.
Designers of the company managed to create a sleeping bag, hot, reliable and comfortable for a dream, which “is regularly updated” taking into account the last technical innovations. So, in the modern Inferno version for a fight against a dampness of a sleeping bag ProDown down with water-repellent processing, and the “breathing” membrane NeoVent Air fabric which applied in legs, a hood and a back as the most inclined to a soaking used. Developers also took care of risk of migration of a heater. In the most problem area – from sides, down packages differ in small dimensions and have the trapezoid form which is not allowing swelled to be displaced even after several seasons.
The warmest model – Inferno-40 offers a fine ratio of weight and thermal insulation – at a rate of Long (201х84 cm), it weighs only 1 928 grammes (without compression bag). At the same time, the packing sizes of a bag are small too – only 30.5х56 cm which can be reduced compression slings. Designers of The North Face managed to reach it not only due to use of high quality down with F.P. 800 and light fabrics, but also thanks to small technical “trick”. The lightning of sleeping bags of Inferno occupies only ½ their lengths that considerably reduced an amount of fabric and a heater when tailoring. Especially for a convenience of disclosure developers arranged lightning on the centre. Many to the user will find this solution disputable since it excludes a possibility of a clasping of sleeping bags. But so in a bag will sit very conveniently, without taking off a jacket, for example, in preparation time of breakfast in the platform of a tent.
Today the Inferno series is presented by four models which differ, mainly, a quantity of a heater at once and calculated on different temperature conditions of use. The warmest – Inferno-40, Inferno-29 and Inferno-18 presented in our shop.
Sleeping bag of Mountain Equipment Everest-40
The British Mountain Equipment brand earned to itself world fame thanks to development and production of sleeping bags what it devoted more than 50 years to and made many essential innovations in this industry. So, designers of the company in 1993 the first created in the sleeping bags well-warmed anatomically office for legs which design was picked up later by other producers.
The warmest sleeping bags of Mountain Equipment enter the Extreme Range series among which Everest is one of the most popular and demanded models. Structurally difficult scheme of an arrangement of down packages, different in a form, both vertical, and trapezoid is characteristic of all sleeping bags from this ruler. They I interfere with the migration of down and formation of “cold points” for many years of operation, providing high thermal insulation. At the same time, developers paid special attention to problem areas. So, the adjustable volume hood of Everest consists of 8(!) trapezoid down packages, and office for legs – from 6, for the maximum thermal insulation and stability of a down filler. With the same purpose side, seams are most displaced down, practically coming under a back of sleeping. The double warming level and a collar exclude loss of heat through lightning and in a neck.
The separate mention cost by the company lining of EXL possessing an elastic line. It attracts down packages closer to a body of sleeping, helping to keep warmly in a sleeping bag, without changing its external contours. The heater remains most straightened, and thermal insulation of a sleeping bag not broken. As showed tests, with other things being equal, the lining of EXL allowed the increasing temperature in a sleeping bag by 2 °C. Very quite good result if to consider that this way does not add to a weight sleeping bag.
For tailoring of Mountain Equipment Everest the company “breathing” DriLite Loft fabric with a water resistance of 1 500 mm is used. Thanks to it to down morning condensate, thawed snow is not terrible or if you inadvertently nestle on a wet wall of a tent. It is necessary to carry to pluses of DriLoft not only the water resistance and high vapour permeability but also small weight thanks to which down can finish on all the volume that only improves the thermal insulation of a sleeping bag. For stuffing of sleeping bags of the Extreme Range series high-quality goose down with F.P is used. 850+.
The Mountain Equipment company of one of the began to test the sleeping bags actively and to investigate various opportunities for improvement of their design. An own laboratory was for this purpose created, and following the results of tests on various people the considerable statistics is saved up. Own standard by definition of temperature condition which British called “Good Night Sleep Temp” became one of the results of this work. According to many testers, it is comparable to “the lower limit of comfort” according to the EN 13537 test.
Sleeping bags of Marmot CWM and Marmot Col
A sleeping bag which does not need representations. Marmot CWM issued not the first year, sustained many “reprintings” and in the popularity can argue with The North Face Inferno easily. As well as Mountain Equipment, Marmot began the history with the production of hot down jackets and sleeping bags for climbers. Before the introduction of the international standards and development of the general techniques of testing, developers of sleeping bags Marmot were influenced by them independently to determine the recommended operation temperature. In solar California for testing of prototypes founders of a brand had to use the refrigerator camera. Perhaps therefore and today CWM – one of the warmest sleeping bags in the “weight category”.
Marmot CWM differs in a delicate design of down packages which interferes with migration of a heater and reduces a risk of formation of “cold points”. To exclude moisture influence, for tailoring very light membrane Pertex Shield fabric, with a water resistance of 10 000 mm is used. This key updating in CWM sleeping bag in recent years. To Pertex, in it, the company membrane of Marmot MemBrain which was made by the Toray company was used. For weight reduction in a lining of CWM the Pertex Microlight fabric possessing excellent down – the holding properties are used.
A recognisable feature of sleeping bags of Marmot is Nautilus hood. In the CWM model, it is cut out from 6 down packages that provide high thermal insulation and does it very convenient in use. Also, it is possible to refer existence of a convenient secret pocket on the level warming lightning to “company” features of CWM, and also “sensitive” cords which are very easy for groping in the dark.
Marmot Col is “younger brother” of a sleeping bag which differs in a smaller quantity of the used heater and, respectively, other temperature range. Unlike CWM calculated on rather comfortable application at -40 °C, Col is focused on more “sparing” use temperature in -29 °C.
As a heater for both sleeping bags gooses down with F.P is used. 800 which passes a double test for quality check – at first the international laboratory IDFL, and then directly on production Marmot. For comprehensive control tailoring and filling of down packages for sleeping bags of CWM is carried out in the homeland of a brand – in California at the Marmot enterprise in Rohnert Park town.
Sleeping bags of Rab Expedition
From the moment of the basis, the British Rab brand specialises in development and production of clothes, accessories and sleeping bags for climbers. Certainly, in their catalogue, it was not without several models of the sleeping bags created especially for extremely low temperatures characteristic of high-rise ascensions. They presented by the Expedition series where three models which differ only with a quantity of the used heater and, respectively, temperature condition – Rab Expedition 1400 (-40 °C), Rab Expedition 1200 (-35 °C) and Rab Expedition 1000 (-30 °C) enter.
Key an element in a design of all series is an application of long vertical down packages of internal partitions of FlowGate. They considerably reduce migration of a heater and at the same time provide excellent circulation of heated air, providing its stream along a torso to a belt, evenly warming a body of sleeping. The hood and office for legs in Rab Expedition are made of very waterproof membrane fabric. Pertex Endurance which also applied in a lining of a hood and position to legs acts as external material very strong for the weight. For stuffing of sleeping bags of the Expedition series, high-quality goose down with F.P used. 850+. For the maximum quality control all down sleeping bags of Rab jam manually in the homeland of a brand – in the County of Derbyshire.
As well as in Mountain Equipment, experts from Rab carefully tested the sleeping bags even before the emergence of the certificate of EN 13537. The experience accumulated by them did not go to waste and now used for determination of temperature range of exceptionally warm sleeping bags. It is called as Rab Limit and approximately corresponds to “the lower limit of comfort” according to the EN 13537 test.
Sleeping bag of Haglofs Perseus-26
Haglofs Perseus is the only sleeping bag in our review which tested on compliance to the EN 13537 standard that gives a chance correctly to compare it to the majority of the sleeping bags presented at the market. In spite of the fact that it “coldest” among the models considered by us, it heat-insulating properties will be to enough most of climbers and fans of winter tourism. Especially, if to consider impressively the low weight of Haglofs Perseus – the size of 190 cm it averages only 1 820 grammes! Designers managed to achieve it due to using of the central lighting, use of especially light Pertex Quantum and Endurance fabrics, and also thanks to stuffing by goose down with F.P. 850. The fact that the weight of Perseus could be a little lower is interesting, but developers inserted a synthetic heater of Haglofs QuadFusion + into those zones of a bag where down is most strongly rumpled by a body of sleeping. Thereby they achieved a little best thermal insulation in these areas, having also reduced a risk of formation of “cold points”.
As well as all sleeping bags for extremely low temperatures, Perseus allows sleeping directly in outerwear though the lower limit of a comfortable dream according to the EN 13537 test pays off proceeding from use only of a set of a dense, layered clothing, socks and a hat. So having, also, warmed in it, it will be possible to sleep very comfortably not only at -26 °C, but also at lower temperatures.
Pleasant trifles in Haglofs Perseus are an existence of external and internal loops for drying, and also a minimalist compression bag with the glued seams which protects a sleeping bag from moisture in a campaign.