At what time should the house be heated at the latest?

In many homes across the country, radiators are staying cold much longer than usual this year. But is that safe? And what role does humidity play in cold rooms?

Humidity affects the risk of mould. Especially if there is no heating, caution is needed.

At what point at the latest should you start heating?

Here, one should not focus on a specific date or an outdoor temperature, but on the recommended temperatures for indoor spaces.

For example, recommendations are 20 to 22 degrees for living rooms,
for children’s rooms and bathrooms, the guideline value is 23 °C
for kitchens, 18 to 19 °C and
16 to 18 degrees for bedrooms.
You can lower the temperature a little by dressing warmer. However, the temperature at home should not fall much below these values.

What can happen if you don’t heat or heat too late?

The whole house gradually cools down. People then often feel that there is a draught. It is just that the floors and walls are so cold that this impression is created, because temperature differences in the room cause draughts without windows or doors being open. If moisture is then added, for example by showering, by drying clothes or by our skin, which also gives off moisture, or by exhaling, the house becomes damp and mould can develop over a long period of time. Structural damage can also occur, such as wallpaper coming loose.

So, if you are still putting off heating, do you currently need to ventilate more?

Basically, ventilation is important. Cross-ventilation should take place two to three times a day so that all the air in the room is replaced with fresh air. However, in autumn and winter, the air entering the rooms is not only dry, but also very cold. Then the humidity drops, but the rooms remain cold or become even colder.

Why is the actual humidity sometimes higher after airing and not lower than before?

When it is foggy or raining outside, the outside air is also humid.
“It is best to ventilate when the humidity outside is no higher than inside”.
We recommend using a hygrometer for outside and one for inside. But you should ventilate in any case. Only: “Depending on how humid the air is outside, ventilation should be longer or shorter.” The optimum indoor humidity is between 40 and 60 per cent.

Why do the windows fog up on the inside?

That is because warm, moist air from inside hits cold windows. Usually, the humidity in rooms is too high.
The moisture must be removed from the windows so that mould does not develop.

What are the reasons for high humidity?

Apart from classics like showering or drying clothes, moisture also comes from our homes themselves; brick walls or furniture, for example, absorb it and slowly release it over time.

What are the benefits of gap ventilation?

This ventilation is in no way an alternative to good cross ventilation, as the air exchange here is far too small to transport all the old, stale air outside.
If the window is left ajar all day, there is also a risk of mould growth. This is because the window frame cools sharply, air accumulates and condensation forms.
At first glance, this gap ventilation seems like a good idea: it makes many people feel good that some fresh air is always coming in and that they are not in some kind of terrarium. But especially in this humid, winter season, it is not recommended.

Want to measure room temperature and humidity or have it monitored over a longer period of time?

With our special data loggers, we can monitor various room air parameters and document them graphically.

We will gladly send you a non-binding offer.