Hier ist die englische Übersetzung des Textes:

---

Imagine a room where two people are present, such as our living room or bedroom.

To remove CO2 from the room, we open the windows and close them after a few minutes. Maybe the windows were open all day. So, it seems perfectly ventilated and ready to spend the evening and night there.

But how long does it take for the air quality to deteriorate to the point where it needs to be ventilated again? This depends on whether the air is still being actively circulated with a fan or if we are moving in the room.

If we sit or sleep and the air is not actively moved, we reach CO2 concentrations of 2000 ppm and more around us after just a few breaths. Already at this point, our body reacts with inflammation, stress, fatigue, and many other often unnoticed symptoms.

Thus, the ventilation had almost no lasting effect.

If we use a fan to circulate the air, the CO2 concentration increases evenly throughout the room. However, according to our measurements, with two people, a limit of 600 ppm is guaranteed to be exceeded after 10 minutes. After 20 minutes, the 1000 ppm mark is certainly reached. Both are thresholds that, in our opinion, should not be exceeded or only very briefly.

What did ventilating during the day accomplish then? The answer is simple: nothing.

However, if the window is permanently open, the chances are good that one will not reach too high values overnight. At least as long as there is wind outside. Without wind, this method is also ineffective.

Only with the window permanently open and a fan supplying fresh air, is it possible to maintain a reasonably low CO2 level.

And that's why intermittent ventilation is ineffective.

Inhalt folgt in Kürze....