Condensation is when the moisture contained in the air in a gas state , turns into a liquid water. This takes place when air which has high levels of humidity (Water content) comes into contact with a cold surface and cools from a gas state to a liquid state. The higher the temperature the more water the air can hold in its gaseous state. Therefore condensation is always likely to occur on the coldest spot, usually the windows. It also forms on surfaces where there is low levels of air circulation, such as behind beds pushed up against walls. This is because despite not being the coldest surface, the air does not move around the room and get heated by radiators etc. This gives this stagnant air the chance to cool.
Condensation and active use
Condensation is a naturally occurring process, and as such can be used to generate water in vast quantities for human use. As such many structures are built purely to collect water created by condensation, including air wells and fog fences and can be used to fight the desertification that is affecting large parts of the world by helping to keep moisture levels in the soil high. There is a large educational effort to encourage locals affected by desertification to introduce such systems and deal with the situation.
Condensation in building construction
Condensation in buildings is usually unwanted and can cause Damp, which can lead to mould and subsequent health issues, especially those that affect the respiratory system. Dampness can also lead to wood rot, metal corrosion and energy inefficiency due to increased heat transfer across surfaces that contain high moisture levels.
There are several methods of reducing condensation and fighting mould which are;
- Ventilation – Allow the air to move around, and out of the building to reduce areas of localised high humidity. Ventilating the inside of a property to the outside during heavy rain is unlikely to reduce humidity, as the outside will have a high humidity level in rainy conditions.
- Extract fans – Usually contained in a kitchen or bathroom where high levels of moisture are created these should always be used, especially if there are issues of condensation and damp. If your bathroom or kitchen does not have one, consider getting one installed.
- Heating – By heating your home you will increase the amount of moisture that can be held by the air. The higher the air temperature the more moisture the air can retain.
- Insulation – If walls are insulated they will reduce cold spots on the external walls of a building. This means there are less opportunities for the air to cool and shed moisture. Insulation in general will help raise the air temperature and therefore the amount of heat that can be contained.
- Produce less moisture – Keep your lids on your pans when cooking, this will cook your food quicker, reduce your energy consumption and reduce the volume of water vapor produced.
- Run the cold water into the bath before the warm water. This reduces the amount of warm water evaporating which will decrease the humidity levels and the amount of water vapor that condenses on the nearest cold surface.
- Use a tumble dryer rather than drying clothes on radiators.
- De-humidifiers – You can buy mechanical de-humidifiers as well as passive solutions such as silica gel packages.
- Pull cupboards and beds a few inches of wall surfaces if they are affected by mould this will give the air an opportunity to circulate.
- UV light – Kills mould. Keep your curtains open whenever possible, in cases of extreme mould buy a UV lamp to kill the mould in the area.
- Mould resistance – You can buy paints and clear liquids that will inhibit mould growth. In addition avoid textured wall surfaces, as they will encourage mould growth and the textured surfaces are more difficult to wipe down.
- Bleach – When required you can clean a surface with bleach although you should take care when using this product.