Window Condensation & How To Stop It Trickle Vents - Window and Door Parts Ireland

We’ve all seen window condensation before and probably have seen some children’s hand prints in it but what causes window condensation and where does it usually occur? Well, there are three possible places where condensation can form on your windows or doors.

  1. On the interior surface of the glass or frame.
  2. On the exterior surface of the glass.
  3. Between the two panes of glass.

In each case the cause of the condensation is different. In this blog post I’m going to concentrate on the most troublesome one – condensation on the interior surface. Condensation on the interior surface of windows and doors is a very common problem in Ireland. In the majority of cases it is a seasonal problem. For the autumn and winter months the windows will be drenched with condensation, and in spring and summer there will be no condensation at all.

Why Does Condensation Appear On Windows/Glass?

Condensation forms when warm humid air comes into contact with a cold surface. The coldest surface in your home is more than likely going to be the windows, especially the glazing. Why is this you ask? Heat always travels from hot to cold. Glass has a relatively high thermal conductivity (heat travels through it more easily) compared to other building materials such as the blocks, insulation or wood used to build the walls in your home. For this reason the windows and glazed doors will be colder than any other surface in your home.

Why does condensation appear on windows or glass

Where is the Humid Air Coming From?

In short, us. Over an 8 hour period an adult with produce the equivalent of a quarter of a pint of water just from the moisture in the air we breathe out. It also comes from showers, boiling a kettle, cooking, drying clothes, pets and plants. It all adds up. We only see this moisture when it forms as condensation on our windows and doors. During the winter months we all like to keep our homes as cosy as possible. In turn we try our upmost to prevent stop cold air getting in, and our precious heated air from escaping. So the moist air that is produced in our homes cannot escape, which exacerbates the problem.

Why Do Some Rooms Have More Condensation Than Others?

Bedrooms will probably be the worst rooms. We tend to keep bedroom doors closed, which traps the moist air. Combine this with low outside temperatures at night. You’ll wake up in the morning with your window covered in condensation. Kitchens bathrooms and utility rooms are producers of moisture and are likely areas where you’ll see condensation on your windows.

Are Some Windows More Prone to Condensation Than Others?

Aluminium windows are by far the worst for condensation. As aluminium is a metal it is an excellent conductor of heat. If you put your hand on an aluminium window or door it will feel cold, this is because it is constantly losing heat from inside to outside. If you have aluminium windows, you will notice that the frame will have as much condensation as the glass. Timber and PVC are poor conductors of heat, and usually won’t have any condensation forming on the frames.

Are some windows more prone to condensation - Window and Door Parts Ireland

What Will Happen If I Don’t Do Anything?

This will depend on how much condensation you have. Mould and mildue grows in damp conditions, and is usually found hand in hand with condensation. This mould and mildue can destroy blinds and curtains. It can also damage plaster around windows. It can also potentially cause respiratory issues.

What Can I Do to Stop Condensation on Windows?

Ventilation will help a lot. Opening your windows or installing window trickle vents will help the warm damp air escape and prevent it forming on your windows.

You can check our range of trickle vents here and the video below shows you how to install the trickle vents.

The best thing to do is to tackle the source of the moist air. In kitchens and bathrooms, use the extractor fans to remove the damp air at the source when cooking. Drying wet clothes is one of the biggest contributors to condensation so try to dry clothes outside as much as possible. Or limit the drying of clothes to one area like the utility room rather than in several rooms around the house and then ventilate this room as drying is taking place. In bedrooms, if you don’t have trickle vents fitted open the windows first thing in the morning.

See Through The Window Condensation

Hopefully this post has helped you understand a bit more about what causes condensation on your windows, where it comes from and how you can go about reducing it. Ultimately if you can reduce the moisture in the air – be it by opening more windows or adding a trickle vent – you’ll be able to reduce the amount of condensation on your windows. If you’ve any tips of your own please comment and leave them below or if you need any help with choosing the right trickle vent for your needs then get in touch!