Opening the windows is not enough
If the room air is bad, we open the windows. More or less regularly. And those who wish to save energy during the cold season are better off opening the window wide for three minutes every hour, rather than keeping it slightly open for hours.
Opening the window ensures a fresh supply of oxygen in the room. This is particularly important in winter. However, while the air that streams into the room in winter may be very fresh, it contains too little moisture to humidify warm room air sufficiently.
If we wish to maintain an acceptable level of air humidity during the cold season, it therefore pays us to use a suitable air humidifier.
