A Complete Overview of Window Condensation

If you see condensation on windows in your home, it can be worrying, especially if they are fairly new. 

While you might be concerned that there is a problem, window condensation doesn’t necessarily mean you’ll need an expensive fix or replacement. In fact, condensation on the outside of windows is a good sign that your windows are doing their job.

In this article, we’ll review what condensation is and how it forms, why moisture on windows isn’t always a bad sign, and when you should be concerned.

What is Window Condensation, and How Does it Happen? 

Condensation on windows occurs when water vapour in the air deposits itself on surfaces that are at lower temperatures resulting in fogging or the formation of water droplets.

So, when moist air meets the cold impermeable glass surface of your windows, it can release moisture onto the glass as water droplets – what we know as window condensation.

Because warmer air can hold more moisture than cooler air, condensation is seen when the temperature of window glass is at or below the dew point for the air around it – whether that is outside or inside your home.

In most cases, condensation isn’t caused by a problem with the window itself but rather by the atmospheric and climactic conditions outside.

So why do people think window condensation is bad? 

Condensation on windows in winter or summer can often cause people to be concerned that there is a problem with their window glass or seal.

The constant moisture caused by condensation can lead to mould and other bacteria developing on the frame, which can cause staining and make it look unappealing.

Is Window Condensation Always a Bad Sign?

Believe it or not, condensation can be a good thing, as it indicates that the window is creating an effective barrier between the air outside and the inside of your home.

Window condensation on the outside of windows: 

If you see condensation on the outside of your windows during the winter, you don’t need to have any concerns. This means that your windows are doing a great job keeping the heat inside rather than letting it escape.

Newer windows have double or triple glazing, and the most energy-efficient models also feature low emissivity coatings or low conductance gas between the panes.

Because of this, they do such a good job of preventing heat transfer, the external pane remains relatively cool, which is why condensation can form on the outside.

Window condensation on the inside of windows:

While condensation on the inside of your window could indicate a problem with the glass or seal, it is more likely due to internal humidity levels.

Internal condensation is often seen in winter because we keep our doors and windows closed to stay warm. As a result, air doesn’t circulate as much as it should, and humidity levels can build. When this humid air touches the cool glass, condensation forms.

The good news is that you can take steps to reduce this type of condensation (see below).

When is Window Condensation a Concern?

Sometimes, condensation can be a sign something is wrong with your windows. Here are a couple of instances where you should be more worried about seeing window condensation:

  • When interior trim and walls are showing signs of moisture damage:

If your interior walls are damp to the touch, or your interior window trim is stained or “swelling,” it could mean that your windows are not doing their job of keeping water to the outside of your home. This can ultimately lead to mould, fungus and structural damage if left too long.

  • When mould is collecting around your windows: 

In the damp west coast environment, mould can quickly grow in sliding window tracks. However, this can be removed easily by cleaning and disinfecting the window tracks twice a year. 

If you see mould developing on the outside of the frames or the area around your window, this could indicate that water has gotten into your walls. Get a professional to look at this as soon as you notice it.

  • Condensation Between Double Pane Windows: 

Condensation, or fogging, forming between the panes of glass is more common in older double glazing, usually because the seal on the window unit has broken down, allowing air to enter the space between the two panes.

In this situation, you will likely have to replace the glass unit or the entire window. If you see condensation between panes, seek advice from a professional to understand the best option to correct the issue.

How Do You Get Rid of Window Condensation?

Whether your window condensation is harmless or not, it can be annoying. Here are some ways you can help to prevent it:

  • Turn Down the Humidifier: While humidifiers prevent dry air in your house in the summer, they can contribute to condensation in the winter. Turn it off or to a minimum setting to help.
  • Circulate the Air: Preventing condensation can be as simple as allowing for some air circulation to enter the room, especially in moisture-heavy rooms such as the kitchen and bathroom. Turn on the ceiling fan or use a stand-up fan to help eliminate humidity.
  • Open Your Windows: Letting fresh air into your home for a short time each day will circulate the air and release moisture. 
  • Vent outside: Ensure your dryer exhaust is venting outside to prevent extra moisture in the air. If possible, open a window while doing your laundry.

When Should a Window Be Replaced?

If the aforementioned tips do not help, you may want to consider replacing your windows. 

Budget Glass’s window experts can evaluate your windows and advise whether replacement is required. Whether you need repairs or complete window replacements, our team can keep your home and windows healthy all year round.

Our vinyl windows can be custom designed to meet your design and performance criteria. In addition, they can be manufactured with double or triple-glazed sealed units in various glass packages to suit your style and energy efficiency needs.  

Based in Nanaimo, BC, and serving the mid-island region, Budget Glass offers a full residential glass service including window replacement, weather stripping, re-glazing and more. Contact us today to find out how we can help you.