What is condensation?

condensation on window

Drawing smiley faces on a window covered in condensation is probably a good few peoples earliest memory. Those of us who still like to indulge their inner child might well still draw the odd face on the shower screen or on the car window when the mood takes us. I’m guiltily as charged on that one, I’m not ashamed to say.

Condensation, as much as it is a great tool of childhood amusement, can actually cause a huge number of problems in a home and is something that, if left to build up day after day, month after month, can cause some long term damage.

Condensation is quite simple to get rid of once you know why it occurs and the reasons behind it. So this is a Dummies Guide To Condensation that will explain what condensation is and how you can reduce it.

How condensation forms

All air contains small amounts of water, warm air holds more than cold air though. As air warms up it’s capacity to carry water increases and so, if there is a source of water nearby, it starts to fill up with water vapour. To give you an example, when you’re cooking, the air in the kitchen will warm up and all the steam created by boiling vegetables/rice/pasta will eventually make its way into the air and stay there, suspended, until something changes.

This is fine until the air begins to cool down, as it cools the air can’t hold as much water and so it begins to deposit some of it on any nearby surface. This could be anything from cupboard doors and windows to the ceiling and walls. The cooler the surface better though.

The best way to think of this is to think of a sponge being squeezed, suddenly all the holes that were storing water are half the size they used to be and water is squeezed out of the sponge onto your hand.

Why are windows only covered in condensation?

Usually the only place that is covered in condensation is the window. This is because it is often the coldest surface in a room by quite a long way, as a result when the air comes in to contact with the window it is cooled very quickly and has to release the water vapour it was carrying onto the surface of the window.

This doesn’t usually happen with other surfaces as they are not that much colder than the air and so the air doesn’t cool and doesn’t need to get rid of it’s water.

Sources of condensation

Cooking is only one source of condensation, here’s a quick run down of some other common ones:

  1. You! Breathing adds a lot of moisture to the air which is why bedroom windows are often covered in the morning.
  2. Baths and showers.
  3. Cleaning/mopping etc
  4. Rain, if it is a warm day and it rains then the air will become very humid

Getting rid of condensation

Getting rid of condensation is all about replacing the damp, heavy warm air with fresh, dryer air. Typically, it is suggested the if you open a window this will solve the problem, if however the condensation has already built up then this can take ages. It’s better to leave a nearby window on vent for a long time or even permanently.

The downside to this is that in winter we need as much of that warm air to stay in the house to keep us warm and so it has to be a balancing act. If you can keep a window on vent whilst you’re doing something that you know will create a lot of steam or damp warm air then that will go a long way to reducing your condensation levels.

If you live in a very old house and have a long term problem that is causing mould then you may want to consider a dehumidifier. The downside of this is that they are not cheap to run so, once again, it is a balancing act.

  Simon Barker

  house and home, tips, warmth, windows

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