If you've recently installed new double glazed windows, you may have noticed a surprising phenomenon: condensation forming on the outside of the glass. While it might seem like a cause for concern, this exterior condensation is actually a good sign. In this post, we’ll explore why this happens and why it’s a positive indicator of the efficiency of your new windows.

What Causes Condensation on the Outside of Double Glazed Windows?

Exterior condensation occurs when moisture in the outside air condenses on the surface of the glass. This happens because double glazed windows are so effective at insulating your home that the outer pane of glass stays cooler than single-glazed or poorly insulated windows. When the outside temperature drops and the air is humid, moisture in the air condenses on the cooler surface of the glass, causing the fogging effect.

Why Is This a Good Sign?

Condensation on the outside of your double glazed windows actually shows that your windows are doing their job. It means the heat inside your home is staying where it should—inside. In other words, your windows are preventing heat from escaping, keeping the inner pane warmer and the outer pane cooler. This level of insulation is key to reducing energy consumption and keeping your home comfortable.

When Is Condensation Likely to Happen?

Condensation on the outside of your windows is most likely to occur under certain weather conditions:

  • Cool, clear mornings: Exterior condensation tends to form early in the morning when the outside air is cooler, but the humidity is high.
  • High humidity: The higher the moisture content in the air, the more likely it is to condense on cold surfaces like your windows.
  • Recent rain: After a period of rain, the air is typically more humid, increasing the chances of condensation.

Is There Anything to Worry About?

In most cases, exterior condensation is not something to worry about. It's a natural occurrence and indicates that your windows are energy-efficient. However, if you're noticing condensation between the two panes of glass, that can indicate a problem with the window seal, which would require attention.

How to Reduce Exterior Condensation

While exterior condensation is usually harmless, it can obstruct your view or become a bit of an inconvenience. Here are a few ways to reduce the occurrence of condensation on the outside of your windows:

  • Keep surrounding areas ventilated: Increasing air circulation around your windows can help reduce moisture buildup.
  • Install window awnings: Adding awnings or other coverings can reduce how much moisture accumulates on your windows during cooler mornings.
  • Apply an anti-condensation coating: Some products can be applied to the exterior of your windows to reduce the amount of condensation that forms.

While it might seem unusual, exterior condensation on new double glazed windows is actually a sign that your windows are performing well. It means they are keeping your home warm and energy-efficient by preventing heat from escaping. As long as the condensation is on the outside of the window and not between the panes, there’s no cause for concern. If anything, this fogging is a reassuring indicator that your investment in double glazing is paying off!