Is it convenient to ventilate when it rains? The dangers of not regulating the humidity at home

Ventilation is important for many reasons. For example: reduces the concentration of viruses, particles and toxic gases, and regulates humidity, It should not be too much or too little.

Although we know that we have to ventilate, doubts may arise as to whether it is necessary to do it when it rains. In rainy weather, does ventilation have the same meaning as in dry days?

Ventilation and humidity: is it good to air the house after the rain?

You should not neglect ventilation even when it rains and this is so for the following reasons:

When you ventilate, you exchange the air inside a room with the air outside. When it rains, the humidity outside is close to 100% and it may seem like it is too much, but you have to take the temperature into account. If the outside temperature is 10 ºC, when the air enters the house at 20 ºC, relative humidity is reduced to 50%, which is an appropriate number. In addition, in winter, due to the heating, the interiors are usually very dry, which is not beneficial for the respiratory tract and the skin.

By the way, the fact that it’s raining it does not automatically mean that the outside humidity is high. Relative humidity depends on a number of factors, including temperature. Most weather reports also give relative humidity.

Prevent mold with ventilation and heating

We have already seen that ventilation makes sense when it rains, but there is an exception:

If it is as cold outside as it is inside, ventilating when it rains can excessively increase the humidity in the room. If you want to avoid mold in winter, you not only have to ventilate, but also heat. It is important not to let the interior temperature drop below 16ºC to avoid mold.

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Ventilated skylights: are they useful after the rain?

With an open window there is a risk of rain falling into the room. The solution is windows with integrated micro-ventilation systems They constantly filter a small amount of air, so you don’t have to worry about opening them and there are no major temperature changes.

The inclination of the tilt-and-turn windows is not enough, since air exchange is usually not sufficient, unless they are kept open for a long time, but in this case too much heat can be lost. Also, the area around the window can get cold, which encourages the formation of condensation and mold.

On the other hand, air conditioning systems can also be used to ventilate without opening the windows.

The keys to ventilation and humidity

Up to what level of humidity should be ventilated?

The optimum humidity in living spaces is between 40% and 50%. You should ventilate when the air is too humid, that is, when the humidity is above 50%, and when the air is too dry, that is, when the humidity is below 40%.

Is the humidity higher when it rains?

Sometimes rain, snow, and muggy weather can increase indoor humidity levels. Regular ventilation can prevent excess moisture in rooms.

How long do you have to ventilate in autumn?

In autumn it is convenient to ventilate the room several times a day between 5 and 10 minutes with the window completely open. On days when it rains continuously, mornings and afternoons are the best times to ventilate.

What you should keep in mind when ventilating when it rains

Especially when outside temperatures are cold, you must ventilate intermittently or cross. Open one or more windows fully for 3-5 minutes so that the air can quickly regenerate.

In spring and autumn you can keep the windows open longer. It is recommended to completely replace the air three to four times a day, regardless of the weather.

A hygrometer will help you keep track of indoor humidity. This way, you can know when you should ventilate. Hygrometers are cheap and can be found at hardware stores.