Dew point simply explained– how to regulate the dew point for an optimum indoor climate

Read on to find out:  

• What is condensation? Condensation simply explained
• Dew point simply explained
• Relationship between dew point and condensation 
• Meaning of dew point in the home
• Tips for avoiding condensation
• Dehumidifier as a solution against high humidity
• Conclusion

What is condensation? Condensation simply explained

Condensation is the physical process by which water vapour in the air turns into water. This process occurs when moist air meets a cooler surface and cools down there. The water vapour can no longer be held in the air and settles in the form of water droplets. This process can be observed particularly well on steamed-up window panes or on bathroom mirrors after a hot shower.

Dew point simply explained

The dew point is the temperature at which the air contains so much moisture that it begins to release water vapour. Warm air can absorb more water vapour than cold air. If the temperature drops, it can hold less and less moisture. If the air can no longer hold the excess water vapour, small droplets form. This is called condensation. 

This principle can be easily explained using an everyday example. A cold drink in the summer heat forms condensation on the surface of the glass because the warm, moist air hits the cooler surface and cools down there. The same thing happens on windows, for example. The temperature difference between inside and outside influences the dew point because warm air can hold more moisture than cold air. When warm indoor air meets a cold surface, it cools down and reaches the dew point, causing condensation to form and the window pane to mist up.

Relationship between dew point and condensation

Dew point and condensation are closely linked. As soon as a surface is colder than the dew point of the air, condensation sets in – in other words, water forms. At a high dew point, the air contains a lot of moisture and water can already form on warmer surfaces. 

Everyday examples that illustrate the topic are described below. 

• Glasses mist up: when you come into a warm room from the cold, the lenses of your glasses will mist up. The humid room air condenses on the cold lenses. 
• Steam kettle: when you boil water, the steam rises and hits cool surfaces such as the kitchen wall or window. The steam condenses there and turns back into water. 
• Bathroom mirror after showering: the mirror mists up because the warm, moist air hits the cool surface.

Meaning of dew point in the home

Permanently high humidity combined with large temperature differences between surfaces such as windows, walls and floors lead to moisture condensing in the colder areas. This encourages mould growth and moisture damage. This becomes visible, for example, through damaged materials or peeling wallpaper. The damage caused by mould is particularly problematic, as it not only impairs the indoor climate and causes damage to walls, furniture and textiles, but also poses serious health risks. Respiratory diseases, allergies and chronic complaints can be the result, and there is also a suspicion that mould could be carcinogenic. 

In addition, a room climate that is too humid simply feels uncomfortable. An optimum humidity level of 40–60 %, on the other hand, ensures a pleasant and optimal indoor climate.

Tips for avoiding condensation

There are a few tried and tested methods to prevent moisture damage. The air should be exchanged several times a day by airing the room, especially after showering or cooking. It is important not to tilt the window permanently, but to let in fresh air for short periods of time. 

Correct heating also plays a key role. A constant room temperature helps to avoid large temperature fluctuations, which can contribute to condensation. A hygrometer can be used to keep an eye on the humidity. In addition to these factors, the placement of furniture also plays an important role. Large cupboard furniture should not be placed directly against external walls as this impedes air circulation. A minimum distance of five centimeters can help to prevent moisture accumulating behind the furniture.

Dehumidifier as a solution against high humidity

If the relative humidity of the room air is constantly above 60 %, the use of a dehumidifier is recommended. These devices remove water from the air and keep the relative humidity at an optimum level. 

A dehumidifier can help, especially in basements or poorly ventilated bedrooms and living rooms. It is also used to speed up the drying of rooms in new buildings or after water damage.

Conclusion

Controlling humidity and temperature is important for an optimal indoor climate. The humidity and temperature in the room can be easily monitored with a hygrometer. If you ventilate regularly, heat properly and ensure good air circulation, you can minimise the risk of humidity problems. Dehumidifiers are an important aid in reducing excessive humidity. These measures help to maintain a pleasant living climate in the long term.

Would you like to find out more about how a dehumidifier can help you feel better or what different dehumidifier systems are available? You can find more information on our information page about humidifying the air.

More about dehumidifying the air

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