The rise in energy prices and high environmental pollution caused by exhaust gases have led to an increasing importance of saving heating energy in today's world. Various structural and technical measures, such as improved thermal insulation of buildings and the use of low-temperature and condensing technology in conjunction with optimal control, address this issue. However, there are often significant savings potential in the heating and ventilation habits of the residents as well. More frequently, damp spots and the formation of mold are observed on the exterior walls of apartments. The causes of these undesirable phenomena are partly due to construction defects, but often also stem from incorrect heating and ventilation behavior of the residents. For instance, some apartment users do not adjust their habits accordingly after installing insulating windows.