while we cozy up indoors at 70°F – a 90-degree difference separated only by the windows.
This stark contrast creates the perfect environment for condensation on windows, but the good
news is that it can be mitigated with the right strategies.
Why Does Condensation on Windows Occur?
Condensation forms when warm, moist air meets a cold surface. The air cools, losing its
capacity to hold moisture, which condenses into water droplets—a phenomenon called
reaching the dew point. For homeowners, this can manifest as foggy windows or even
water pooling on windowsills, particularly in winter.
How to Stop Condensation on Windows: Tips for Homeowners
Increase Window Surface Temperature
Insulated glass with low-E coatings and gas fills, such as argon or krypton, improves thermal performance and maintains a warmer inner pane. Additional panes – such as triple or quadruple glazing – help keep the interior glass surface closer to room temperature, making it less likely for the glass to reach the dew point and form condensation.
Insulated window treatments can also help maintain a stable indoor temperature while allowing airflow.
Improve Air Circulation
Moving air helps prevent it from cooling below the dew point near windows. Run the furnace fan and open curtains and blinds so warm air can circulate around the glass and prevent stagnant pockets of cool air that lead to condensation.
Keep Indoor Humidity Levels Between 30-50%
Homeowners who want to know how to stop condensation on windows should ensure clothes dryers, stove exhaust fans, and bathroom fans are vented outside to expel moist air. Use a dehumidifier to remove excess moisture from the air until humidity levels reach the optimal range. If humidity is still high, consider upgrading to an HVAC system with air exchangers or humidistats.
How to Stop Condensation on Windows: Tips for Contractors
Contractors play a key role in preventing window condensation during construction and
remodeling projects. Here are some preventative measures they can take:
Select the Right Windows
- Use double- or triple-pane windows with gas fills for improved insulation.
- Opt for low-E coatings to reflect heat and maintain a consistent glass temperature.
- Incorporate thermal breaks to reduce temperature gradients between indoors and outdoors.
Seal and Insulate Properly
- Apply high-quality weatherstripping and caulking to eliminate drafts.
- Check for air leaks during installation to ensure a tight seal.
Ensure Adequate Ventilation
- Install and vent exhaust fans in kitchens and bathrooms to manage humidity.
- In energy-efficient homes, use mechanical ventilation systems like heat recovery ventilators (HRVs) or energy recovery ventilators (ERVs) to maintain airflow.
Advise Clients on Humidity Management
- Recommend portable or whole-house dehumidifiers for humid climates.
- Educate homeowners on simple practices, such as avoiding indoor clothes drying and using exhaust fans when cooking or showering.
Partnering for Success
By combining high-quality materials, expert installation, and homeowner education, contractors can prevent condensation on windows and protect homes from moisture-related issues like mold and rotting frames.
Simonson Lumber is here to support contractors with premium window materials and expert advice. Let us work together to ensure your clients’ homes stay warm, dry, and comfortable all winter long. Contact us today to learn more!