Why am I getting condensation on my windows?

With colder temperatures outside, we tend to see condensation more regularly on our windows. It is only normal to find yourself asking ‘why am I getting condensation on my windows?’ We all get fed up with seeing moisture on our windows, but there are many ways we can prevent the build up of condensation in our homes before it leads to a more serious problem.

At Trade Windows, we want to let you know the best ways to prevent condensation on your windows and in your home. Understanding the causes is important for knowing how to prevent the build-up of moisture.

What is condensation?

Condensation is the process where water vapour becomes liquid. It can occur in two ways; either the moist cool air is cooled quickly to the dew point, or the air becomes so saturated with water vapour that it cannot hold any more water. For example, if warm air comes into contact with a cool window, the water vapour in the atmosphere would be cooled quicker, creating droplets of water, which is known as condensation.

Why am I getting condensation on my windows?

PVCu windows Derby

Winter is the worst time for condensation. The outside air temperature is a lot colder than the warm air indoors. This larger temperature difference means the air is cooled down much quicker. During this time of year, most people keep their windows shut to trap the heat in. As ventilation in houses is reduced, there are less ways for the moisture in the air to escape. This creates the perfect conditions for condensation to form.

Condensation can lead to streaming windows, damp walls, peeling wallpaper, a musty smell, and even the growth of black mould. Damp and mould can lead to respiratory problems, but don’t worry, there are many ways to prevent condensation before it leads to mould.

Internal condensation

There are many ways condensation can be caused inside. Typically, if occurring inside, condensation can be bad if it’s not dealt with.

Causes of internal condensation include:

  • Boiling liquids when cooking
  • Drying clothes inside
  • Showering or bathing
  • Activities which create steam, (e.g., steam ironing or steam removal of wallpaper)
  • Low levels of ventilation
  • Leaking pipes

If condensation is caused by steam from the bathroom or kitchen, this is usually fine as there has been a direct cause. When condensation appears without a cause, it can mean the humidity in your home is too high. Without proper ventilation, this can create further issues.

External condensation

pvcu window house derby

There is little you can do to prevent external condensation, but it tends to mean your windows are working correctly as the outside humidity is staying outside. External condensation typically only occurs in summer when the temperatures outside are warmer and more humid than those inside. It usually lasts for a few hours in the morning and quickly disappears in the sun. It can be more of an issue near rivers or lakes, and on windows that are more sheltered. External condensation is a sign the seals on your window are properly sealing and insulating your home.

Condensation between window panes

Condensation between your window panes is a cause for concern. This shouldn’t occur in double or triple glazing as they should remain sealed. This can be an issue with the seal, or it could suggest the whole window needs replacing. If this occurs, it is likely the window is leaking, and your home is no longer efficiently insulated. You can get the insulated glass unit replaced but, in some cases, you may need to replace the entire window.

How to prevent condensation on my windows

There are a few ways you can prevent and reduce condensation before it becomes more widespread and causes damage to the interior of your home.

1. Increase ventilation

The quickest and easiest way to reduce condensation on your windows is to increase the ventilation in your home. In the cold weather you may not want to open your windows, but doing so after showering or cooking can quickly lower the levels of humidity in your home. Make sure you’re closing the doors of these rooms to stop the moisture spreading further through your house.

In winter it can be tempting to close the trickle vents on your windows as they let in draughts. However, trickle vents are important for helping lower the humidity of a room and keeping the air fresh and clean. By allowing a constant flow of air, the levels of condensation in your home are reduced.

2. Change how you dry your clothes

In winter it can be harder to dry your clothes outside, but this is the best way to prevent condensation in your home as the moisture from your wet clothes is not trapped inside. If you are unable to dry your clothes outside at this time of year, try and limit your drying to one room.

Many of us like to dry our clothes on radiators but this can increase the rate of condensation in a room, especially in winter. Drying your clothes on a radiator means the moisture is carried into the room on a warm air current, making it stick to the first cold surface it hits. Using a clothes horse or drying rack is a better way to dry your clothes as the air can circulate easier. Limit your drying to one room and keep a window open. Keep the door closed so the moisture can’t reach the rest of your house.

3. Use a dehumidifier

Dehumidifiers take moisture from the air, making it harder for condensation to be deposited on surfaces. Some can be expensive as they use a lot of energy, but you can get smaller ones which are quite cheap. If there’s a room or window with more condensation than others, it may be worth looking for a more long-term solution, such as replacing your window.

Benefits of new windows from Trade Windows

Slimline Aluminium windows from Trade Windows, Derby

If you’re struggling with mould or other issues caused by condensation on your windows, getting new windows is the best solution. At Trade Windows, we have a wide range and style of windows available for your Derbyshire home. Our windows can help prevent condensation from forming, whilst keeping your home warm as they have an excellent level of thermal efficiency. All our windows can be upgraded to Trade Secure windows for extra security.


If you still have questions about condensation on your windows or want to discuss our window options further, don’t hesitate to give us a call on 01332 755551 to chat with a member of our expert team.