Window condensation

Window condensation is a process that occurs in different forms. Condensation is possible on both the inside and outside of windows and is caused by a temperature difference between building interiors and exterior conditions. When warm humid air meets cold surfaces, such as window glass, it collects and forms the water droplets or steaming up, more commonly referred to as condensation.

Due to the potential associated health risks, the most problematic type of window condensation occurs on the glazing's interior. Especially prevalent in bathrooms and kitchens after cooking or showering, without correct ventilation interiors often contain much warm moist air or excess water vapour.

The molecules in this air move closer together as the gas approaches a colder surface, such as a window.

When the warm air cools, the molecules clump together until dew point is reached and condensation occurs. The risk of this happening is increased with a higher temperature difference between inside and out and occurs most often during cooler months. Poorly insulated windows that allow the cold from outside to cool the inner most pane, also play a central role.

Condensation on the inside of windows is an issue because it creates a wet environment, ideal for mould to form, which can lead to lung-related health issues.

There are, however, several measures that can be easily taken that help with reducing window condensation, including:

• Drying clothes outside or in a tumble dryer

• Regularly airing interiors or using extractors to improve ventilation

• Purchasing new, modern well-insulated windows

• Correct use of central heating

All the above actions should help to either reduce the amount of water vapour in the air or prevent the interior pane of glass from having such a cold surface. Improvements in these two key areas will in turn reduce condensation on windows.

Condensation on windows does not just occur on the interior. Sometimes it can also form between panes.

This a big indicator that the window seals are not working effectively to prevent moisture from entering the interior structure.

The windows should therefore be replaced by a modern, more insulating model so that they no longer trap moisture.

It is important that the spaces between window glass panes are sealed so they can function well to slow heat transfer via conduction.

Many modern windows also use a sealed inert gas, like argon, to fill these spaces, which further enhances thermal performance as it is denser than air.

Occasionally condensation forms on window exteriors. This is not such an issue though and can actually indicate that triple or double-glazed windows are effective or that a house is especially well sealed. External condensation may happen on early summer mornings as humid outside air rapidly warms before condensing onto cooler glass.

For such cases, there are a few ways to help prevent condensation. This includes slightly lowering the intensity of any whole house ventilation system and cutting back shrubs in front of the window to allow excess moisture to evapourate.

In general, for particularly energy-efficient and standard buildings alike, regular ventilation via open windows is recommended to allow fresh air to enter and built-up humidity or excessive moisture to exit.

Well-insulated windows play a key role in terms of energy saving and having the surface temperature of the inner most windowpane better match that of the interior air temperature to stop condensation from forming. At windows24.com we offer a wide range of high-quality and energy-efficient windows spanning five different material categories, from modern uPVC to sturdy wood, and durable aluminium.

In their most basic configuration, all our windows feature double glazing, consisting of two panes, to prevent energy loss and conduction through the profile. Triple glazing with three panes and additional carbon fibre cores or seals are then also available for maximum thermal performance. Just head to configurator to select the options today, input your desired dimensions, and browse through our quality finishes for tailored design, including vibrant RAL colours, authentic decors, and additional panels or bars.