What causes condensation on windows?

Condensation, or "sweating," is a natural occurrence on all windows and is caused by excess humidity, or invisible water vapor, present in the air. When this water vapor comes in contact with a surface which is at a cooler temperature, the vapor turns to visible droplets of moisture.

Each window has many features built in to keep the temperature of the glass as warm as possible and thus reduce condensation. Our insulating glass units provide superior energy efficiency to reduce the potential for condensation. However, there is no such thing as a condensation-free window in high humidity conditions. Controlling the amount of moisture in your home is the most effective action you can take to avoid condensation.