Exciting cause – Why do some windows fog up from the outside in the morning?

Good windows play an important role in saving heating costs, but as a tenant you rarely have any influence on the quality of the building in the apartment – you have to make do with what you have.

Misted windows initially cause a cloudy view, regardless of whether the condensation collects on the inside or outside of the pane. But only in one of the two cases do you have an urgent need for action to avoid damage in the long term.

Windows fog up on the outside

The good news: If your windows fog up from the outside, you don’t have to do anything. It is a positive sign and speaks for the quality of the windows.

So if condensation collects on the outside, the windows have good insulation properties and let little heat from the inside out. The outer pane is therefore relatively cold – if it is colder than the air, the windows will fog up.

After the morning hours, the water usually evaporates quickly and you have a clear view through your windows.

Real problem: windows fog up from the inside

If the opposite is the case and the windows constantly fog up from the inside, then this is a problem and you should definitely take action. There is then too much moisture in the air – the risk of mold increases.

You can combat this with the following measures:

• remove the condensation with an absorbent cloth and wipe dry
• change your airing habits and get used to regular airing
• Constant room temperatures of 20 degrees and a maximum humidity of 60 percent are ideal
• ventilate after cooking and showering to get rid of the resulting moisture directly
• if you have set night reduction for the heating, then ventilate again beforehand, otherwise the warm room air will condense when it cools down
• if possible, do not dry laundry in living quarters
• avoid using humidifiers and evaporators on radiators

By the way: Windows can fog up on the inside, even in well-insulated buildings. Because while poorly insulated windows draw warm air and moisture outside, airtight windows keep it inside.

The original of this post “Why do some windows fog up from the outside in the morning?” comes from chip.de.