Condensation Resources
My windows are working so hard they are sweating!
While this may be an entertaining punch line of a cartoon, sweating windows are no laughing matter. In fact, the windows themselves do not sweat.
Condensation is the result of environmental conditions that allows the moisture in the air to collect on the glass or window frame in a home. This effect is similar to the presence of dewy grass on summer mornings or the fogging of a mirror after a hot shower. When conditions are ripe, condensation can appear on either the inside or the outside. So what are those conditions?
The dew point is the temperature at which the air is fully saturated with moisture, or humidity. When a surface is cooler than the dew point, moisture is drawn out of the humid air and “condenses” on the cool surface. A good example of this effect is a glass of cold ice tea on a hot, humid day. In a matter of minutes, the cold glass will begin to draw moisture out of the humid air and beads of moisture will appear on the cold glass.
In short, large temperature differences from the air to the glass or window frame coupled with high relative humidity creates condensation or “sweating windows”.
Condensation can be very problematic and damaging, potentially resulting in:
- Damp feeling inside the home
- Discoloration of interior surfaces
- Mold or Mildew on surfaces
- Warped wooden surfaces
- Peeling or blistering interior or exterior paint
- Sweating Pipes
- Damage to walls or framing members
In fact, some newer homes can actually be more susceptible to condensation. Newer homes are constructed with more weather tight materials than older home. Vapor barriers and modern construction methods are designed to reduce air leakage. At the same time, these can act to seal in moisture. Unless provisions are made to allow the moisture to escape, moisture buildup can result.
The most effective way to alleviate condensation concerns is to control the relative humidity inside your home. Drier air is less likely to condense. The following tips will help with humidity:
- Use exhaust fans in rooms where water is being used heavily: bathrooms, kitchens, even laundry rooms. If exhaust fans are not available, crack windows
- If you use a humidifier, be sure it is set to the correct outside temperature
- An improperly vented clothes dryer will introduce significant moisture. Be sure the dryer is venting properly and completely
- Be sure crawl spaces, attics, or basements are properly ventilated
- Install energy efficient windows
No window can “prevent” condensation from occurring. However, the more energy efficient windows will reduce the probability of condensation forming. Metal frame windows are notorious for condensation because metals transfer energy very rapidly, moving the outside temperature to the inside your home and creating a “cold” spot for moisture to collect. Vinyl framed windows will maintain warmer inside temperatures and decreasing the likelihood of “cold” spots ripe for condensation. In addition, glass packages can have a significant impact on condensation. Advanced coatings and spacer systems will maintain warmer temperatures inside the home.
Even the highest performing window will not eliminate condensation. Large temperature differences with humid conditions can cause condensation to occur on even the best window on the market.
Please consult our Full Energy Results page to find WeatherBarr products with low U-Values and high Condensation Resistance Factor (CF) that can help control your condensation problems.
