Condensation on the inside of windows is a common issue, especially in the colder months. This phenomenon occurs when warm, moist air inside the home comes into contact with the cooler surface of the window glass. Understanding the causes and science behind interior window condensation can help homeowners effectively address and prevent it.
This blog is one of three in a series breaking down condensation issues with windows. Luckily, interior window condensation is the easiest to address, so let’s fix this issue first!
The Science Behind Interior Window Condensation
Interior window condensation is similar to what happens when a cold beverage forms droplets on a hot day. When warm, moist air meets a cooler surface, the air cools rapidly, losing its ability to hold moisture. This excess moisture then condenses into liquid droplets on the surface of the window. Essentially, water as a gas has more energy than water as a liquid, so when it cools enough (loses energy), it will convert into a liquid state (and if it cooled even more, it could freeze into a solid).
This process is also governed by the principles of relative humidity and dew point. Relative humidity is the amount of moisture in the air relative to what the air can hold at that temperature. The dew point is the temperature at which air becomes saturated with moisture and water droplets begin to form. When the temperature of the window glass is at or below the dew point of the air inside your home, condensation will occur.
But why do some windows get fogged up with condensation and others don’t? Below, we share the primary causes of interior window condensation so you can test out some solutions yourself.
1. Trapped Warm Air
One of the top causes of interior window condensation is trapped warm air. Window coverings such as curtains or blinds can trap warm air between them and the window. This warm air, when in contact with the cooler glass surface, causes condensation to form. This is particularly common during winter when indoor heating is high and windows are typically cooler.
2. High Humidity Levels
High humidity levels inside the home can also lead to window condensation. Everyday activities such as cooking, bathing, and even breathing contribute to indoor humidity. During seasonal changes in spring and fall, indoor humidity levels can naturally rise, exacerbating the problem. Inadequate ventilation in areas where moisture is generated can also contribute to higher humidity levels and subsequent window condensation.
Consider purchasing a dehumidifier and see if the problem clears up.
3. Poor Insulation
Windows that are not properly insulated can be a major cause of condensation. Poor insulation allows cold air to seep in and warm air to escape, creating a temperature differential that leads to condensation. Ensuring your windows are well-insulated can help prevent this issue.
4. Unsealed Windows
Windows that are not properly sealed can allow moisture to penetrate and cause condensation. Over time, seals can degrade, leading to gaps where moisture can enter. Regularly checking and maintaining window seals can help prevent condensation.
5. Houseplants
Houseplants are often an overlooked cause of interior window condensation. Plants release moisture into the air through a process called transpiration. Having many plants near windows can increase the humidity levels around those windows, leading to condensation.
But this isn’t true for all plants. Some soak up moisture from the surrounding air, so do a quick Google search to see if the plants you have are humidifying or dehumidifying.
6. New Construction or Renovation
Newly built homes or recent renovations can contribute to higher humidity levels due to the drying out of building materials such as concrete, plaster, and paint. This additional moisture in the air can lead to increased condensation on windows but will pass with time.
It Might Be Worth a Professional Assessment
Are you struggling with window condensation in your home? Don’t let it lead to mould growth or damage to your windows. Our team at Linton Window & Door is here to help you create a healthier indoor environment.
Contact us today for a consultation and take the first step towards a condensation-free home. And stay tuned for our future posts on moisture between panes and outside your windows.
