From spring through summer, windows left wide open ensure constant air circulation and a natural exchange of air in the living spaces. They simply allow stale air, bacteria, and moisture from drying laundry, showering, or cooking to escape.
Now, the windows remain closed during the day, and the radiators run continuously to ensure that outdoor temperatures don’t come close to—or fall below—indoor temperatures. Fall has arrived, and with it comes the need to ventilate properly, supply rooms with fresh, oxygen-rich air, minimize humidity, and maintain comfortable indoor temperatures.
Stale air indoors is not good for your health at all
Ventilation is simply good for you. Stale indoor air is replaced with oxygen-rich, dry fresh air, and unpleasant odors are simply expelled outdoors. Stale air in living and workspaces can even lead to health problems in sensitive individuals, such as skin irritation, breathing difficulties, fatigue, or allergic reactions. Sometimes it’s also invisible mold spores that are inhaled through the respiratory tract and can cause irritation such as a runny nose or inflammation of the mucous membranes.
In general, however, stuffy air in living spaces—and especially in bedrooms—is unhealthy for everyone. When fine dust, viruses, bacteria, or unpleasant odors are also present, they contaminate the indoor environment, impair health, and can make breathing difficult. Indoor spaces regularly refreshed with fresh air are therefore essential for a comfortable and healthy indoor environment. Proper ventilation is a skill that must be learned and practiced to prevent stuffy air from developing in the first place. Here’s how to do it best.
It's best to ventilate thoroughly and cross-ventilate throughout the day
To feel truly comfortable at home during the colder months, with a pleasant room temperature and air quality, these two factors must work in harmony. It is not advisable to leave windows slightly open during the day, as this would result in insufficient air exchange. In addition, this causes the window frames and the room to cool down, which in turn could promote mold growth. Comfort and a fresh, healthy indoor climate in your living space can be achieved through intermittent or cross-ventilation for up to about five minutes. While intermittent ventilation involves opening only one window, cross-ventilation involves opening windows on opposite sides of the room for about five minutes to expel stale air and let in fresh air. It’s important to turn off the heat during both burst and cross-ventilation so the apartment doesn’t cool down. According to energie-fachberater.de, the higher the outside temperature, the longer you need to ventilate. Air exchange works differently depending on the season. The greater the temperature difference between indoors and outdoors, the faster the air exchange occurs.
Open all the windows, please—when ventilating, it's even allowed to do this several times a day
As a general guideline for optimal ventilation, you should ensure a draft—and thus a thorough exchange of air—in indoor spaces at least three times a day. Of course, ventilation always depends on the number of people present, the size of the living space, and the airtightness and insulation of the rooms. This applies to homes, workplaces, and schools.
Houseplants can purify the air and have a positive effect on human well-being and the indoor environment. However, they are by no means a substitute for ventilation. This is because plants also release moisture into their surroundings, and moisture is the ideal breeding ground for mold. Adequate ventilation therefore also helps prevent harmful mold growth.
The moisture generated while showering or bathing should always be allowed to escape immediately afterward through open windows or a suitable ventilation system. The same applies to the kitchen. Water vapor and moisture produced while cooking, as well as unpleasant odors, should be ventilated out promptly.
Ventilation is especially important during flu and COVID-19 outbreaks
This coming winter, ventilation in schools, public buildings, and homes deserves special attention. In addition to the annual flu season, the coronavirus continues to spread. Regular ventilation can significantly reduce the risk of infection. So: dress warmly in layers and open the windows for fresh air and a healthy indoor environment.
