Condensation occurs when water vapour is cooled to the point where it condenses as water droplets on a cold surface. Greater accumulations of condensation will appear on colder window temperatures and homes with high humidity levels. To reduce the amount of condensation on your windows you can:

Reduce the humidity levels in your house

  • Ensure that your home has appropriate exterior water barriers to protect your home from outdoor moisture.
  • Your kitchen and bathrooms should have ventilation fans to expel indoor moisture.
  • Fix all water leaks into the basement and do not allow any standing water in the house or against the foundation wall.
  • If necessary, install a sump pump to remove excessive moisture from the soil under the slab.
  • Disconnect any humidifiers (if not necessary).
  • If required, use a dehumidifier.

Increase the surface temperature of your windows and frames

  • Invest in window frames made out of vinyl, wood or fiberglass.
  • Energy efficient windows made with a double or triple glaze and low-E (low-emissivity) will also increase the temperature of your windows and reduce condensation build-up.
  • Draftproof your windows with weatherstripping tape.

Did you see a building science or energy efficiency term you did not understand? Check out our glossary.