Thursday 10 May 2018

How To Reduce Condensation

With improvements in modern living conditions, condensation is becoming a more common problem. Condensation occurs when saturated air, which is holding a lot of moisture, comes into contact with a surface that has a lower temperature. With windows this occurs when the outside temperature is a lot lower than the room temperature.

There are several things can increase the moisture level of air inside a property. Some examples include, cooking, washing up, bathing and even breathing. All these things occur in every home across the country, so how do you reduce the levels of condensation on your windows?


By draught proofing windows and doors, the ventilation of the windows is reduced. This leads to higher levels of water vapor in the air. Ventilation can be improved by using extractor fans, installing trickle vents or by opening your windows for a few minutes each day.

Double Glazing

In a room that is kept to a warm temperature, installing double glazing can help reduce condensation by working as an insulator to maintain a higher surface temperature of the glass on the room side.

The Location of the Condensation

The location of the condensation on the glass can often help identify the source of the problem.

If the condensation is on the room side of the inner glass the temperature of the glass surface is too low for the water content. To solve this the room should be regularly ventilated and kept warm in colder weather. Wherever practicable, radiators should be installed under windows to maintain the temperature of the inner glass.

However, if the condensation has appeared in-between the two panes of glass in an airtight sealed double glazed unit, the seal will have failed.

Condensation on the outside of the outer glass is normal and is not something to worry about.

Condensation in Period Properties

Houses which have been completely sealed by the installation of cavity wall insulation, loft insulation, double glazing and draught proofing are likely to become moisture traps. In these cases, condensation is likely to be a ventilation issue. Provided the rooms are heated, the solution will often be found by providing controlled ventilation.

In the case of the older buildings which have not been draught proofed, the main reason for condensation is likely to be the indoor temperature. Increasing the warmth in the room or introducing localised heat near the windows will often resolve the problem.

Casement Window with trickle vents

Open sash window

Bathroom Timber Windows