What Causes Condensation on Windows and How to Prevent It

What Causes Window Condensation?

There are three types of window condensation to know about: interior window condensation, exterior window condensation and between-the-panes window condensation. Once you have identified where condensation is forming in your home, you are in a much better position to understand what factors may be causing it, and how to prevent and stop it.

• • Interior window condensation develops during the winter months. This occurs because the temperature outside is colder and dryer than the temperature indoors.
  • Exterior window condensation happens more frequently in the summer months. This is because the temperature outside is warm and humid, while the air conditioner is making the window cold inside. This type of condensation is usually what we call “dew” and is seen first thing in the morning. It is not damaging to anything.
  • A fogginess or wet spot between your window panes is a concern. This can be a sign of broken seals, broken panes or leakage around the window. Make sure you always try cleaning and drying the window first to make certain your problem lies between the panes.

How to Stop and Prevent Window Condensation

The way to resolve your condensation problem relies heavily on the type of condensation you are seeing. Here are some tips to reduce or eliminate moisture based on the particular type of condensation issue:

• • Interior window condensation can be helped by reducing humidity inside your home.
    • • Use a de-humidifier or a product called DampRid that draws moisture out of the air is one way to change the humidity in your house.
      • Use your shower fan when bathing and the kitchen fan when cooking.
      • Try leaving your interior doors open and fans on, even during the winter, to circulate the air.
      • Open the windows when it’s not too cold to dry out your home.
      • Installing weather stripping or caulking around windows may also help, as well.
      • If you turn your heat on during the winter, consider setting it just a few degrees cooler to help prevent condensation build-up.
  • You can eliminate or cut back on exterior window condensation with these simple tricks:
    • • Trim back trees and shrubs from around windows
      • Leave the curtains or blinds open at night
      • Set your A/C on a higher temperature
      • Just wait—the sunshine will absorb the moisture fairly quickly anyways!
  • Foggy, hazy or wet spots between the panes of double- or triple-paned glass is not as easily fixed. A professional window company can replace seals and panes, but often this situation will require more. If your windows are old, it may be time to replace them.