Does airing increase the humidity in winter?

The impression is often created that the outside air contains more moisture than the air indoors which is not always true. During the winter, if you open the window when the outside air is colder than the air indoors, the cold air will come into contact with the warmer air and the level of humidity will fall automatically. Here is a quick numerical example to illustrate this: If the relative humidity outdoors with an outside temperature of 0°C is 69%, that corresponds to a relative humidity indoors of just 18% with a temperature of 20°C. This is due to the water absorption capacity of the air at different temperatures. You can use a hygrometer to find out whether the humidity within your home is at the optimum level of between 40% and 60%. To find out more about ideal humidity and how it is measured, watch this video.

After purchasing a humidifier to solve the problem of low humidity, the question often arises as to whether you will still be able to sleep with the window open or tilted open. The answer is no as that would be counter-productive. The humidifier provides the air with a constant supply of moisture while at the same time, the cold and very dry air from outside also enters the room through the window. That is why we recommend the well-known method of «inrush airing» because you still need to supply your home with fresh air somehow. So in the morning and evening, open your windows wide for a few minutes to let the fresh air in and then close them completely after ventilating your home – your humidifier can then carry on doing its job effectively.

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