What causes condensation on my windows?
Condensation on the interior of windows occurs when warm humid air inside your home comes into contact with cool glass. This is especially common in the winter when outside air is cold and dry and indoor air is warm and humid.
So, how can I stop or reduce window condensation?
Often people think there is something wrong with their home or their windows that cause it. Not necessarily. Condensation is physics. It’s natural. There are ways to manage condensation quite easily and quickly if it’s a problem for you.
The 3 key factors that cause condensation are:
1. Ventilation: You may think you have to install an indoor ventilation unit. It’s an option if that’s what you want. Ventilation really means airflow. Keeping the space open or ventilated by simply opening the windows for a while is the easiest and quickest way to manage condensation. I grew up in the north hemisphere where the outside temperature can be -15C in winter. We would still open our windows for 5 - 10 mins every morning. I’ve learned recently that it’s such a common thing to do in Germany there is even a word for it - Stoßlüften.
2. Indoor humidity: The point where condensation starts to form is called the Dew point. If you like to get technical, a calculator can be found online. The coastal areas’ humidity is generally higher than inland areas, so the Dew point will be relatively high as well. Other factors that increase indoor humidity are cooking / steaming in the kitchen, showering / bathing in the bathroom and breathing in a small and closed bedroom. In some cases high indoor humidity level could be caused by water leakage or water damage in the house which should be investigated by professionals and resolved as soon as you can.
A comfortable indoor humidity level in summer would be around 45%. It’s recommended that indoor humidity level should be kept under 40% in winter for condensation management. Installing an indoor dehumidifier is a good option to control your indoor humidity level.
3. Windows: People often turn to windows first as that’s where the condensation occurs. Replacing single glazed leaky windows with double glazing may help but may not. When you have leaky windows, it has some airflow in the space. When you replace them with double glazing, the space becomes more airtight. If the indoor humidity level in the room remains the same and no airflow, you probably will have more condensation.
Replacing windows can help as the air gap in the double glazing will reduce the heat transfer through the glass. Non thermally broken aluminium framed double glazing will not perform much better than single glazing in terms of condensation management due to the heat transfer through the frame. For this reason all our windows and doors are supplied with thermal breaks, so heat transfer is dramatically reduced. Higher performing homes may use triple glazed windows, have a larger thermal break or even utilise timber frames. When the whole house is airtight with Heat Recovery Ventilation (HRV) installed to control indoor air quality and humidity, it can really stop condensation.
In conclusion, replacing windows with double or triple glazing is a great way to improve your home insulation but it may not be the solution for your home condensation management.
Contact us via m@mlwindows.com.au or learn more about ML Windows at https://www.mlwindows.com.au