As a rule, the ideal humidity in the home is between 40 and 60 percent, even in winter. Above that value, the risk of condensation and mould increases; below it, the air can feel dry. Measure the humidity with a hygrometer and ventilate daily, even when it is cold outside.
What is the ideal humidity in the home in winter?
Humidity is usually expressed as relative humidity: the percentage of water vapour in the air compared to the maximum amount the air can contain at that temperature. The value of 40 to 60 percent is a commonly used rule of thumb, not a legal standard. Milieu Centraal does not specify a fixed percentage itself, but emphasises ventilation to prevent moisture problems.
In winter, moisture builds up more quickly in the home. You close the windows more often, the heating goes on, and cooking, showering, breathing, and drying laundry add water vapour every day. According to the KNMI forecast for 31 October, it will remain dry and sunny for the coming days, but light night frost is possible from Thursday 5 November. Precisely during such a transition from autumn to winter, many people start heating more often and ventilating less.
How do you measure the humidity in the home?
The only reliable answer comes from a hygrometer: an inexpensive measuring instrument that shows the relative humidity. Hang or place it on an interior wall, not directly next to the shower, a window, or a radiator, because you will measure an inaccurate value there. Do not look at a single moment, but monitor the value for a few days, also in the morning after showering and in the evening after cooking. Milieu Centraal points out that a CO2 meter can sometimes also show how humid it is inside, because both levels rise if there is insufficient ventilation.
What happens when the humidity is too high?
If the humidity remains high for a long time, you will often see this in fogged-up windows, a musty smell, or damp patches. According to Milieu Centraal, residents in almost 1 in 5 homes suffer from moisture or mould, especially in damp rooms such as the bathroom and bedroom. According to the organisation, mould is a sign of moisture problems and insufficient fresh air. Also read why you get condensation on your windows and what you can do about it. We have written a separate article about the possible symptoms: can too high humidity cause health problems. If you have health problems that you attribute to moisture or mould, talk to your GP; a device is not a treatment.
What can you do if the humidity is not right?
| Relative humidity | What it means | What you can do |
|---|---|---|
| Below around 40% | The air can feel dry | Do not heat excessively; ventilate briefly and effectively. Read when a humidifier makes sense |
| Around 40 to 60% | A comfortable range according to the rule of thumb | Continue to ventilate daily |
| Above around 60% | Increased risk of condensation and mould | Ventilate extra, do not dry laundry in living spaces, and consider using a dehumidifier |
Milieu Centraal advises ventilating all year round, so also in winter. According to Milieu Centraal, opening a window for 20 to 30 minutes while showering is enough; longer can actually lead to condensation and mould because the room becomes too cold. Curious whether a bowl of water on the radiator makes a difference to the humidity? Read our article about the bowl of water on the radiator.
When does a dehumidifier help?
A dehumidifier is a supplement to ventilation, not a replacement. Milieu Centraal states that dehumidifiers only work in a small, enclosed space without new moisture and that they consume a lot of electricity. It can therefore be useful in a utility room, basement, or laundry room where the humidity remains structurally high and ventilation is not sufficient. For persistent moisture problems, also look for the cause, such as a leak or cold bridge.
Dynter DH251 dehumidifier is a compact dehumidifier for spaces up to 55 m².
Dehumidification: up to 900 ml per day
Water tank: 3800 ml, with a safety sensor that switches off the device when the tank is full
Consumption: 80 W
Extras: timer from 1 to 24 hours, night mode where the display turns off, and ambient light
Dimensions and weight: 24 x 13.4 x 37 cm, 2.51 kg
Direct answer: as a rule, the ideal humidity in the home is between 40 and 60 percent. Measure with a hygrometer, ventilate all year round, and only use a dehumidifier as a supplement for persistently high humidity.
Do you want to actively tackle moisture in an enclosed space? View the Dynter dehumidifier DH251 or the entire dehumidifier collection. How long such a device needs to run can be found in how long a dehumidifier needs to run per day.
Frequently asked questions
What humidity is too high in the home?
As a rule of thumb, a relative humidity above 60 percent is too high in the long term. Then the risk of condensation on windows and mould increases. A short peak after showering or cooking is normal.
Should I ventilate in winter when it is cold?
Yes. Milieu Centraal advises ventilating day and night all year round, also in winter. You can ventilate briefly with windows opposite each other and temporarily lower the thermostat.
How do I lower the humidity in the home?
Ventilate extra during and after cooking and showering, preferably dry laundry outside or in a ventilated room, and find the source of the moisture. For persistently high values in an enclosed space, a dehumidifier can help. Also read how to dry laundry indoors without a dryer and without mould.
Is a hygrometer necessary?
It is not necessary, but it is the only way to know what value you have at home. Without measuring, you are going by feel, and that is unreliable when it comes to moisture.