Waking up to streaming windows is a familiar sight for many people, especially in winter and this is usually the first sign of a condensation problem. If condensation occurs over a prolonged period of time, other signs will start to appear such as damp patches on walls, peeling wallpaper and ultimately black mould growth. These effects can lead to musty smells, damage the fabric of our homes and can even affect our health.
Have you ever noticed the droplets of water that form on the outside of a canned drink when you take it out of the fridge? This is condensation and the reason why it happens is all to do with temperature, air and water vapour.
The temperature on the surface of the can is reduced as air passes over it. As the air gets cooler its relative humidity rises and the water vapour turns into moisture. The air passing over the can is unable to hold onto the moisture which ends up as droplets running down the side of the can’s cold surface.
This is what happens in thousands of households across the nation when the temperature drops inside the home, especially at night time when the heating is turned off. Just like the canned drink, the air reaches the point where it can no longer hold onto to all the moisture that we create in our homes and it migrates to the coldest surfaces – the windows and walls – where it appears as condensation or the more familiar sight of streaming windows.
The causes of condensation problems within our homes
Let’s take a closer look at what causes condensation in our homes.
Through the daily routine of showers, baths, boiling kettles, cooking etc, a family of 4 will contribute approximately 4 pints of water per person a day, equal to over 100 pints of water vapour a week, which has to end up somewhere. Before the days of double glazing, wall and loft insulation this humid, stale air would find its escape route through ill-fitting windows and doors, lofts and so on. It would be replaced by fresher, colder air or to you and me – a draught!
Today, after the introduction of energy saving measures such as draught proofing, double glazing and cavity wall insulation there is no natural escape route for this stale, humid air, which is now trapped inside the home. As a result, this trapped and stale air only makes the problem worse, causing condensation on windows, walls and poor indoor air quality.