In the night, the body is composed of respiratory system and perspiration from 200-500ml. (a lot! If the temperature is very low, if the temperature is very low, the temperature in the insulation layer of the sleeping bag will drop below the dew point, and the water will be stored in the insulation layer of the sleeping bag. This is one of the most important things to consider during a long winter camping trip.
In simple terms, in a cold environment, it is good to have both internal and external accounts. If it is not well designed, the problem is unavoidable. Why?
First of all, we can understand where the water comes from. In terms of sleep, one is the water vapor that evaporates from the body, and the other is the water vapor that comes out of the mouth, which is very different.
Moisture is a ventilation function coating fabrics can breathe, and mouth shout out the beginning of the water, because of the larger amount of exhaled, out of the mouth becomes vapor after the cold, white sand, is already a small water droplets, is greater than that of microporous breathable coating fabric, rarely can breathe, of more than one hundred pieces of one meter, such as Goretex micro porous membrane fabric on the inside and outside temperature difference will be the internal environment of the fogging problem, how much more is not breathable PU fabric tent? If the ventilation cover is low, the water vapor will be less than the speed of the exhalation, and the iron will be solidified in the inner layer of the fabric, and the window will be frosted with frost.
Because of the cost problem, the fabric of the tent is cheap PU coating, this kind of coating is not breathable at all, like plastic cloth, must be condensed. Tent PU coated fabric prices in four to eight blocks of one meter, clothing cheap a venting capability of PU coating fabric, the so-called low through (3000) under the air price over 12 ~ 18 a metre, tent material is more than ten meters, less is more dozens of meters, use breathable material cost amazing! Ferrino's MonsterLite alpine tents are sold for thousands of dollars in breathable fabrics.
There are many ways to avoid this:
Keep ventilated, this is the design of the tent, each have a long time, especially single layer bottom (floor and account is sewn together), the top must be ventilated good, otherwise condensate water will flow down.
Choose bag bottom air inside account of double tents, condensate will be suitable to external accounts, here it is important to note that the account ventilation ability, it is dangerous if ventilation is not good, just condensate well, if the condensed water in a cold environment, account continuously frost caused a completely airtight closed account will be stuffy dead.
The big tent can make a fire, not a fire. ...
In there will not be called out water vapor environment choose breathable fabric tent (in the absence of weight requirements to choose cotton tents, breathable moisture permeability of ao), and chosen and prevent splashing water, prevent wet face cloth after lower venting capability, this depends on how much money...