Have you noticed condensation on the inside of your windows?
While window condensation is a common occurrence, many homeowners are concerned about the potential damage condensation can cause to their homes. The good news is that in most cases, condensation is not a window defect. It’s usually a sign that there’s too much moisture in the air inside your home.
In this guide, we’ll break down:
- What window condensation is
- What causes it
- How to reduce and prevent it
TLDR: Quick Answer
- Condensation happens when warm, humid air hits cold glass
- It’s most common in winter
- It usually means indoor humidity is too high
- Reduce moisture and improve airflow to fix it
- Moisture between panes is a different issue
Watch: What Causes Condensation (and How to Fix It)
If you’d like to see how this works and what to adjust in your home, watch the quick video below:
What is Window Condensation?
Window condensation is a thin layer of moisture that forms on the surface of your glass.
It happens when the temperature of the glass is colder than the surrounding air. When warm air comes into contact with that cold surface, moisture forms.
Windows tend to collect condensation more than walls because glass cools down faster and lacks insulation.
What Causes Window Condensation?
The main cause is simple: warm, humid air meeting cold glass.
This is especially common in winter because:
- Outdoor temperatures drop
- Indoor air stays warm
- Daily activities add moisture to the air
Common sources of indoor humidity include:
- Cooking
- Showering
- Drying clothes indoors
During summer, condensation can also form on the outside of windows. This usually happens when warm, humid air meets cooler glass, often due to air conditioning inside the home.
Newer, energy-efficient windows can sometimes show more interior condensation because they seal your home better and prevent moisture from escaping.
When Should You Be Concerned?
Most condensation is normal.
Normal
- Moisture on the inside surface of the glass
- Light condensation during colder days
Needs Attention
- Frequent or heavy condensation
- Water pooling on sills
- Moisture between the glass panes
Condensation between panes usually means the seal has failed. When that happens, the insulated glass unit no longer performs properly and may need to be replaced.
Condensation or Ice in Winter: What It Means
If you’re seeing condensation or even ice forming on the inside of your windows, it’s usually a humidity issue.
Warm indoor air holds moisture. When it touches cold glass, that moisture turns into condensation. In colder conditions, it can freeze.
To reduce this:
- Run bathroom and kitchen fans when cooking or showering
- Use a dehumidifier to lower indoor moisture
- Keep blinds slightly open so warm air can reach the glass
- Aim for indoor humidity between 30 and 40 percent
If you notice fog or ice between the panes, that’s a different issue and may indicate a failed seal.
How to Prevent Window Condensation
Open Your Windows
Opening your windows allows hot, humid air to escape and lowers the temperature inside your home. This may not be a year-round solution, but it is the quickest way to reduce condensation.
Use a Dehumidifier
Dehumidifiers are electronic devices that draw moisture from the air, reducing the humidity inside your home. They are a great solution for preventing condensation, while also helping to mitigate mold and mildew growth and eliminating musty odors.
Run the Exhaust Fans in Your Home
Everyday activities like cooking and showering naturally generate humidity inside your home, contributing to condensation. You can reduce humidity by routinely running the fans in your kitchen exhaust hood and in your bathroom to help draw moisture out of the air. Running the fans for about 20 minutes after cooking or showering should help mitigate humidity.
Improve Airflow Around Windows
Simple adjustments can make a noticeable difference: keep blinds open a few inches at the bottom, avoid blocking vents with curtains and allow warm air to circulate across the glass.
This helps keep the window surface warmer and reduces condensation.
When to Consider Replacing Your Windows
If condensation is forming between the panes, it usually means the seal has failed.
At that point:
- The window loses efficiency
- Insulation performance drops
- Replacement is often the best long-term solution
Modern windows are designed to:
- Improve energy efficiency
- Reduce heat loss
- Maintain more consistent indoor temperatures
Brookstone windows are designed and manufactured in Canada using high-quality materials and built to meet ENERGY STAR standards. Our team installs every window with precision, and we back our work with a lifetime warranty.
Final Thoughts
Window condensation is common, especially in colder climates.
Most of the time, it’s not a window problem. It’s a sign that your home’s humidity needs to be adjusted.
With a few simple changes, you can reduce moisture, protect your home, and improve overall comfort.
If you’re still dealing with persistent condensation or aren’t sure what’s causing it, it’s worth taking a closer look before it leads to bigger issues.
For more tips or support, visit brookstone.ca/resources