If you are looking for great insulation combined with low weight and a small packing size, down is your choice! No synthetic fibre achieves such a high loft and thus such high insulation power as this natural product. If maintained well down has a longer lifespan than synthetic sleeping bags. It also ensu res a comfortably dry sleeping climate, because it asorbs and transports moisture. However, this is also its major disadvantage: if it gets wet, down can clot and lose its great insulation quality. And once the down is wet, it takes a long time to dry. A drawback not only on multiday winter trips. The body’s moisture condenses in the fill, freezes and cannot dry. This will also be the case in a bivy bag and although a water-proof inlet might help, it will negatively affect the comfortable features of the down.
Use: mountaineering, trekking in areas with low to normal air humidity, bike trips with light luggage.
A disadvantage that is also a great advantage: synthetic fibres hardly absorb moisture and dry a lot faster than down. Also, when they get wet, they retain most of their insulation power. The hollow Polyester fibres can still trap warm air, because they remain stable and do not clot as down. This makes the material ideal for destinations with high air humidity. It’s also the right choice when the temperatures are not too low or the sleeping bag is excessively used and needs to be washed often (children!). Synthetic models are cheaper than down sleeping bags and are easier to maintain.
Use: allround sleeping bags, canoe tours, winter trips, destinations such as Scandinavia with a harsh climate, bike rides with light luggage, cabin tours, summer sleeping bags.
Further factors affecting heat loss:
1. Of course, the body’s temperature is influenced by numerous factors, which cannot be simulated by a dummy in a climate chamber. Also, the sensitivity to temperature is subjective. For example, women are generally more sensitive to cold than men; further factors include age, level of fitness, as well as experience, whether you are exhausted or rested, how much or little you ate, whether you drank alcohol (alcohol lower’s the body’s temperature) etc.
2. External conditions play a crucial role and you can optimise the insulation performance by
- using an efficient sleeping mat, which provides good insulation between sleeping bag and ground.
- wearing functional clothing that keeps you dry and transports moisture from the body. Also, a hat helps retain the body heat. - choosing a well protected, sheltered location: wind and moisture can rapidly cool the body’s temperature.
3. The standardized testing conditions in the climate chamber simulate a ‘common’ daily situation. Please take into consideration that during multi-day activities or severe weather you will experience different conditions and you will have to adjust quickly.
T(COM) » COMFORT TEMPERATURE RANGE
presents the lowest temperature limit at which a standard woman (25 years old/ 60 kg / 1.60 m) can sleep comfortably in the sleeping bag.
This range ensures a comfortable sleep, also for inexperienced users.
T(LIM) » INTERMEDIATE TEMPERATURE RANGE
presents the lowest temperature limit at which a standard man (25 years old / 70 kg / 1.73 m) can sleep comfortably in the sleeping bag.
An experienced user can optimise the insulation qualities by his choice of clothing and further factors.
T(EXT) » EXTREME TEMPERATURE RANGE
presents the minimum temperature a standard woman can remain for six hours without sleep. Under these extreme cold conditions you can expect strong sensation of cold and even a risk of health damage due to frostbite or hypothermia.
SLEEPING MAT – A cold ground or circulating air withdraw body heat – no matter how good the quality of your sleeping bag is! Reduce this conductive heat loss (A) by using a good insulating mat.
WIND PROTECTION – Wind chills! With a slight wind (25 km/h) +5°C will quickly feel more like 0°C. Therefore, limit wind exposure – a tent, bivouac bag or even a big rock can offer good wind protection. (B). Choose the right, wind protec ted spot for the night.
EAT PROPERLY – Your body needs a lot of energy for climbing, hiking, cycling etc. If you don’t provide your body with plenty of ‘fuel’, your body won’t be able to warm up properly.
DRINK PROPERLY – Make sure you drink enough already during the day. A dehydrated body cannot produce heat. Before getting into your sleeping bag get warm with a cup of hot tea or hot chocolate.
AVOID ALCOHOL – Do not consume alcohol in cold temperature. Alcohol may temporarily make you feel warmer, but it soon decreases your body’s temperature.
KEEP YOUR GEAR DRY – Clothes as well as the sleeping bag, down in particular, lose their insulation efficiency when wet. Warm socks quickly become ice cold. Never get into the sack wearing sweaty clothes. If you store your extra clothing in a water-proof sack it stays dry. And also make sure to air out your sleeping bag whenever possible, e.g. on the tent.