Yes, you should also ventilate when using a dehumidifier. A dehumidifier removes moisture from the air, but does not supply fresh air or remove polluted air. Ventilation is therefore still necessary for CO2, odours and fine particles. The two work best together: ventilation as a basis, dehumidification as a supplement.
Why a dehumidifier does not replace ventilation
A dehumidifier works in a closed loop: it draws in moist room air, extracts water from it and blows drier air back. This removes moisture, but the rest of the indoor air simply stays in the house. Carbon dioxide from your breathing, cooking odours and substances from cleaning products are not removed. Milieu Centraal is clear about this: dehumidifiers are not a replacement for ventilation and work mainly in small, enclosed spaces. The RIVM also emphasises that ventilation means that you refresh the indoor air with outdoor air throughout the day.
How much moisture does a household produce?
A household produces an average of about ten litres of moisture per day through cooking, showering and breathing, according to the Who Insulates, Benefits campaign. That moisture has to go somewhere. With a properly functioning ventilation system or open vents, a large part of it escapes outside. If you do not, the moisture will seek out cold surfaces, such as windows and exterior walls. That is exactly how condensation and later mould are formed.
Combining ventilation and dehumidification in winter
The idea that you should keep everything closed in winter to save heat often has the opposite effect. A damp house feels colder and requires more heating energy. A practical approach looks like this:
Keep ventilation vents and mechanical exhaust systems open. This is your basis, even at night. So do not close the vents and do not switch off a mechanical system.
Ventilate targeted. After showering, you can open the window for 20 to 30 minutes; after cooking, turn on the extractor hood. Leaving it open longer cools the room unnecessarily.
Use the dehumidifier during peak times. Think of days when you dry laundry indoors, a bedroom that feels chronically damp, or an enclosed space such as a basement or utility room. Also check our explanation about using a fan and a dehumidifier at the same time.
What humidity level are you aiming for?
A hygrometer shows whether you need your dehumidifier. In our article about the ideal humidity in winter, you can read which levels are comfortable. If the level is still high after ventilating, a dehumidifier is a useful supplement. Is the problem with the windows? Then our article about condensation on windows can also help.
Direct answer: always ventilate and use the dehumidifier as a supplement when the humidity remains high.
Dynter DH251: a compact supplement to ventilation
The Dynter AirPure DH251 is designed to tackle moisture where ventilation alone is not enough. The dehumidifier is easy to move, for example from the bedroom to the bathroom.
Dehumidification: up to 900 ml per day
Water tank: 3800 ml
Suitable for: rooms up to 55 m²
Consumption: 80W
Weight: 2.5 kg
Extras: timer function from 1 to 24 hours, night mode where the display turns off and a safety sensor that switches it off when the tank is full
Ventilation or dehumidification: what suits when?
| Situation | Best approach |
|---|---|
| After showering or cooking | Ventilate briefly and use extraction |
| Daily basis, also at night | Vents open, ventilation system on |
| Drying laundry indoors | Ventilation plus a dehumidifier in the room |
| Damp, enclosed space | Dehumidifier, supplementing ventilation |
Do you want to get moisture under control without losing heat? Then check out the Dynter DH251 dehumidifier or discover the entire collection of dehumidifiers.
Frequently asked questions
Can I close my ventilation vents when the dehumidifier is on?
No. Vents provide the supply of fresh air and the removal of moisture and CO2. A dehumidifier only solves the moisture part.
Should I open windows when the dehumidifier is running?
During dehumidification, the device works best in a room with closed windows. Therefore, ventilate briefly before or after, and let the device do its work in between.
Is a dehumidifier enough against mould?
Not always. Mould often indicates insufficient ventilation or a structural cause such as a leak. A dehumidifier can help, but it does not solve the cause.
How long should I ventilate per day?
Ventilation is a continuous process, also at night and in winter. Supplementary ventilation is done briefly and targeted, for example 10 to 15 minutes after cooking or showering.
What if I live in a well-insulated house?
That is exactly when ventilation is important, because a well-insulated house has little natural air exchange. A dehumidifier can then provide extra help during peaks.