Condensation occurs when moist air reaches the cold glass panes of the window. There are several possible causes for the formation of condensation on the windows and the subsequent mold. On the one hand, it may be that the window profiles were not installed and insulated appropriately. On the other hand, a window sill can also lead to moisture, as well as poor quality of the profiles or glass. The moisture in the air is part of the indoor environment, which comes from cooking, drying laundry, plants or an aquarium, and even from the residents' breathing. And since the glass panes of the windows are the coldest part of a house, these are also the areas that are most susceptible to condensation.
In order to avoid condensation, it is necessary to choose window profiles that have the lowest possible thermal transmittance value. It doesn't matter whether the profile is made of PVC or aluminum. With PVC, however, the value is also influenced, among other things, by the number of chambers - the more the better. At theAluminum profileThis in turn is determined by thermal insulators. The emissivity of the glazing must also be low and the installation of the windows must be perfect. It is important that the thermal insulation of the profiles is outside.
In a humid climate, it's not just the window profiles that play an important role. However, this should have the lowest possible thermal transmittance value. Furthermore, effective ventilation should be considered so that moisture can be removed from the rooms. In this case, radiators that are installed directly under the windows are also advantageous. These heat the vulnerable areas and thus prevent the formation of condensation.
Here, too, ventilation is the be-all and end-all. You should keep in mind that moisture can often occur even after the windows have been replaced, which does not necessarily mean that the window profiles are of poor quality. This is usually a sign that the installation and quality of the new windows is very good. These have a better seal and avoid drafts, which were present in the old windows and which transported the moisture out together with the warm air. You can avoid the “new” moisture by insulating the walls of the house from the outside in addition to the new windows and, as already mentioned, ensuring good ventilation. You can achieve this manually by opening the windows regularly or by having an effective ventilation system installed. There are also modern variants in which such systems are built into the profile.
However, mold can also arise if the connection between the profiles and the wall is poor. If there are small holes or unfilled joints, cold air can penetrate into the rooms, which leads to moisture and an increased risk of mold growth. The problem with mold is not only that it looks unsightly, but above all that it is harmful to health and can even lead to asthma. So check for such problems and possibly fix them.
If the tips mentioned above do not result in any change, the only option left is the most unpleasant option, which is to replace the windows with new, higher quality ones.
