Infectious aerosols: This is why good ventilation is essential

Fresh air supply via window ventilation: One of the most important measures with regard to infection control is a good ventilation of indoor spaces. This is due to the fact that aerosols of the coronavirus, very light infectious droplet nuclei filled with SARS-CoV-2 or one of its variants, are dangerous. The particle clouds are released when people breathe or speak, and are amplified when they cough, sneeze or sing. They spread rapidly throughout the room and can remain suspended in the air for hours, posting a serious risk. Therefore: fresh air supply and air exchange through ventilation, air purifiers and/or appropriate room air conditioning systems are important! How much and how often a room needs to be ventilated depends, among other things, on:

  • Size of the room
  • Number of persons present
  • Duration of stay
  • Type of activity (speaking, talking loudly, singing)
  • Wearing a mouth and nose protection

The Hermann Rietschel Institute at the Technical University of Berlin provides a practical online tool for easily calculating different scenarios.


Summer, sun and the air doesn't move. What to do?

But how to ventilate in summer? Who hasn't experienced it: all the windows are wide open, but the air is stagnant. What was nothing more than a minor annoyance every summer can now lead to a significantly increased risk of infection. This is because: whether impact window ventilation and cross-ventilation (tilt position is not effective!) to be successful depends on several factors:

  • The higher the temperature difference between indoors and outdoors, the faster the air exchange takes place. Where in winter 5 minutes are enough, in summer it is necessary to ventilate for at least 20 minutes.
  • Air exchange can be accomplished especially well when there is a large movement of air outside, i.e. wind.
  • If the air inside and outside has the same temperature and there is no wind at all, simple window ventilation is not enough. The air is stagnant, infectious aerosols can spread unhindered in the room.


The solution: AiroDoctor photocatalytic air purifier

For indoor areas that cannot be adequately and regularly ventilated, experts strongly recommend the use of a professional air purifier, such as the AiroDoctorⓇ. This is because scientific studies repeatedly show how these devices minimize the risk of infection via infectious aerosols. By the way: The purchase of a professional air purifier is also an important and worthwhile purchase beyond the summer. Because, as studies have shown, professional air purifiers provide additional protection against infection even with adequate ventilation.