Why does condensation form on your windows and how can you stop it?

In Quebec, condensation in windows is an extremely common phenomenon that we have all experienced at one time or another. But what is causing this fog on your windows and most importantly, should you be worried?

What causes condensation on windows?

Condensation on windows is caused by the humid air inside your home cooling too quickly. When this warm air comes into contact with cold windows, the water vapor it contains reacts to the temperature change, turning solid. It is this reaction that creates the fog on your windows.

Fog on your new windows that have just been changed?

Many owners are baffled when they discover a build-up of fog on their brand new, freshly replaced windows. But should you really be worried about it?

You'll be happy to hear the answer is no!

Rest assured: the presence of fog on new windows is not only very normal, but it is also a very good sign. Indeed, this condensation means that your new windows, now more waterproof, no longer let heat or humidity escape. In short, there is something to celebrate!

How to prevent and limit condensation?

Of course, fogged up windows in and of themselves shouldn't be a cause for great concern. However, it is true that condensation can be symptomatic of other problems and that a build-up of humidity is not without consequences. So how can we prevent the presence of condensation?

The 3 factors that cause condensation

In order to limit the presence of fogging, you must first limit the conditions that are conducive to its development. Condensation occurs when the following 3 factors are present:

1. Too much humidity in the air

The primary cause of condensation is the presence of moisture in the air. It can be caused by a variety of activities and objects using a large amount of water inside your home: humidifier, shower, dishwasher, aquarium, laundry dryer, etc. Sometimes it can also be attributed to a basement that has excess moisture.

2. Inadequate ventilation

A broken kitchen hood, an unused or defective exhaust fan, a lack of air circulation between the different rooms of your house… All these factors can worsen your condensation problem since the humid ambient air is not effectively replaced.

3. The presence of cold surfaces

Finally, condensation cannot be created without the humid indoor air undergoing a considerable drop in temperature. This phenomenon usually occurs when the steam comes in contact with a cold surface, such as a wall or, more commonly, a window.

How to prevent fogging in 3 steps

You’ve caught on: to prevent condensation, you have to tackle the source of the problem, which is the three conditions conducive to its development. Here are some possible solutions to help you control the situation:

1. Reduce the humidity level in the air

It goes without saying: with less humidity, there is less condensation! Try to reduce the sources of humidity in your home and limit the use of your humidifier. In fact, in some cases it is even recommended to use a dehumidifier, as in the case of a particularly humid basement.

2. Increase the ventilation

Renewing the humid air present in your home is essential to counter the problem of condensation. Make sure your ventilation system is functional and is on when needed. In addition, try to maintain good air distribution between all the rooms in your home. When the weather permits, do not hesitate to open the windows from time to time to ventilate more.

3. Ensure that an adequate temperature is maintained

Certainly, it is normal to see mist on the surface of double or triple windows. Make sure that your heating system provides enough heat to all the rooms in your home, that your walls are well insulated, and that your curtains and blinds are open when the weather is colder.

Need more advice?

At BASCO, we are a team of door and window specialists. If you have any other concerns about the presence of condensation on your windows or for any other question, do not hesitate to contact our experts →