Where does it come from
Since childhood, we all know the effect when you breathe on a cold window, and it starts to fog up. Why is this happening? Room air, having entered our lungs, is heated and saturated with water vapor to a relative humidity of 100% (that is, it absorbs the maximum amount of water that it can carry at the current temperature). When exhaling, in contact with the cold surface of the glass, the air cools down, and its ability to retain water decreases sharply. Those water particles that can no longer be held in the air are deposited on the glass in the form of small droplets of condensate.
For the same reason, condensation also forms in the tent. We breathe, heating and saturating the internal air with water vapor. If it is cool outside, then this air, in contact with the inner surface of the tent, cools and leaves part of the excess moisture in the form of dew. For reference, the average person “evaporates” (loses through the breath and through the skin) about 200-300 g of water per night. So, on cold nights, the formation of condensation inside the tent is an inevitable physical phenomenon.
How to deal with it
First of all, it must be said that condensation in a two-layer tent is not such a serious cause of discomfort. Drops are formed on the outer tent and safely roll down on its surface to the ground, without affecting us and our belongings in any way. The only hassle is to dry the tent in the morning before putting it in a backpack. However, sometimes there are still moments when gusts of wind begin to flap the wet awning and shake off drops of water inside the tent. But these splashes are more of a nuisance than a real threat of getting things wet. At the same time, for single-layer tents, condensation is a real headache, because everything that you “breathed” by morning ends up on the floor and on the walls, next to your sleeping bag.
The only effective way we can combat condensation is to reduce the humidity inside the tent by ventilating it with drier outside air. There is a ventilation system for this.
It allows the tent to blow through with the wind. But, most importantly, it works quite effectively even in its complete absence, due to an effect similar to that occurring in a chimney.
Depending on the specific model of the tent, the ventilation design may differ, but in general there are several general rules that ensure its effectiveness
The vents should be positioned as high as possible (to ensure the best vertical air movement).
The edge of the outer awning is raised high above the ground. Winter tents are made with an awning that reaches ground level or is equipped with a storm skirt. In conditions of strong winds, this is justified, but in a quiet summer camp in such tents, most of the condensate accumulates (it is partly treated by turning up the skirt and partially unbuttoning the entrances).
The ventilation windows can be adjusted to increase or decrease the air flow depending on the weather and personal preference. In windy weather, close. In windless - open. But, in any case, we must remember that the tent needs to be ventilated not only when it is hot, but, paradoxically, also on cold nights in order to minimize the formation of condensate.
However, I repeat, there are conditions when even with fully open ventilation it is impossible to avoid the appearance of condensate. If the humidity of the outdoor air approaches 100%, then it is no longer able to somehow dilute and dry the internal atmosphere of the tent. So drops that form on the inside of the awning during fog or during rain are quite normal (it is often mistaken for tent leakage, but this is rarely true).
Topic: The cuts in the tent of the Dyatlov group are made for ventilation (Read 13125 times)