Also, not really necessary. It's more of an Old Wives Tale than an effective practice.
The only place I have trouble with mold is in the bathroom, and that's because so many homes built before the 80s were built without ventilation fans in the bathroom. The places I've lived with proper ventilation have not had mold problems.
While it’s true germans are plagued with all sort of holistic medicine and homeopathy mind virus, this one is true. With covid wave there was explosion of co2 meters and tons of people realised they live in stuffy air all the time.
What’s depressing is that neither rental rules do not require HRVs yo be installed nor little public places have started to upgrade.
The only place I have trouble with mold is in the bathroom, and that's because so many homes built before the 80s were built without ventilation fans in the bathroom. The places I've lived with proper ventilation have not had mold problems.