A dehumidifier can provide extra support in a room where damp is caused by everyday activities, such as drying laundry, once you’ve checked the ventilation and airflow. If the damp persists without an obvious cause, measure it and check the ventilation. If you notice marks on the walls, France Rénov’ recommends having their cause investigated before relying on a portable appliance.
If condensation appears mainly after a shower or while drying laundry, start by noting when it forms and checking the airflow and ventilation. You can then choose a portable appliance for the room in question, taking noise and water drainage into account.
In a utility room or heated room, compare the stated capacities under their specified test conditions. Check whether a laundry mode, an accessible tank or drainage suited to the room would meet your needs.
Don’t treat an appliance as a solution to the cause of the marks. France Rénov’ recommends having their cause investigated, as it may relate to the walls, insulation, ventilation or rainwater drainage.
When: if you want to monitor changes in a room before choosing a portable appliance.
Limitation: a hygrometer measures humidity, but it doesn’t remove water from the air or identify the cause.
When: for extra support in a specific room, particularly if you regularly dry laundry there, after checking the ventilation.
Bear in mind: it will make some noise, use electricity and require you to manage the collected water. It won’t fix a cause related to the building.
When: if marks appear on the walls or the damp persists despite airing the room and checking the ventilation.
Bear in mind: finding the cause may require contacting your housing provider or a professional, rather than buying another appliance.
Start by considering the possible cause of the damp, then think about the constraints of the room where the appliance would be used.
| Priority | What to check | What I need |
|---|---|---|
| Cause and ventilation | Note when the damp appears. Check the airflow and that the ventilation is working; have any marks on the walls investigated. According to ADEME, mechanical ventilation continuously removes moisture from the home. | Marks persist on my walls: I want to understand the cause before choosing a portable appliance. |
| Monitoring humidity | Use a hygrometer to measure humidity in the room at different times and after airing it. Check what monitoring features the appliance you’re considering offers. | I want to see whether humidity rises mainly after showering, cooking or drying laundry. |
| Room and extraction | Compare capacities in L/24 h and their test conditions. Check the stated room size, recommended operating temperature and dimensions. A stated figure doesn’t guarantee the same results in every room. | For my utility room or small room, I’m looking for an appliance whose operating conditions suit the actual space. |
| Noise and settings | Check the dB(A) rating and which mode it applies to. Consider the humidistat, timer or automatic mode, depending on when you plan to use it. | In a bedroom or home office, I need to consider noise, not just the stated capacity. |
| Water and maintenance | Compare the tank capacity and how easy it is to access. For continuous drainage, check that there’s a suitable outlet and follow the instructions. Also check the recommended maintenance tasks. | If I can’t empty a tank regularly, I need a drainage option that suits where the appliance will be placed. |
A dehumidifier treats the air in a room but won’t establish why a wall is damp. France Rénov’ lists ventilation, insulation and rainwater drainage among the factors to investigate.
Have the cause of the marks investigated before considering an appliance for extra support.
Stated capacities aren’t necessarily measured under the same conditions. For example, De’Longhi gives a capacity of 16 L/24 h at 30 °C and 80 % relative humidity for the DEXD216RF.
Read the test conditions and recommended operating temperature before comparing two figures.
A tank needs to be emptied; a drainage hose needs a suitable outlet. A pump is only useful for a specific need if the water has to be lifted.
Check where the appliance will go and what drainage is available, then read the model’s instructions.
Without suitable drainage, allow time to empty the tank regularly.
In an occupied room, noise levels may affect when you use the appliance. Les Numériques includes noise among the criteria for comparing dehumidifiers.
For a bedroom or home office, check the noise level for the mode you plan to use, as well as the programming options.
These specifications apply to the models mentioned, not to every appliance made by each brand.
Wood’s presents the MDX20P as suitable for drying laundry in a heated room.
According to Duux, the Bora 20/30L range combines a humidistat with app control.
The French-language product information for the Tasciugo AriaDry Multi DEXD216RF gives useful test conditions for understanding its stated capacity.
Les Numériques includes the Comfee Aqua Dry 12 among its recommendations for small rooms.
This selection includes dehumidifiers for a specific room and a hygrometer for monitoring humidity. Whether you choose one of these appliances or have the property checked depends first on the possible cause of the problem.
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For a room where collected water needs to be drained away, this model offers a tank or hose option, which must be used with a suitable outlet. The title states 12 L/jour, a 25 m² coverage area, a 24-hour timer and automatic defrost. If you plan to use it in a bedroom, check the noise level for each mode.
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Auto, Dry and Sleep modes offer options for using the appliance at different times in a specific room. The title lists Wi-Fi, a 24 m² coverage area and a 1.8 L tank; check how often you’d need to empty it for your intended use. If you’re considering it for a bedroom, ask for clarification on the noise level in the mode you want to use: the 32 dB and 38 dB(A) figures given for this model don’t clearly refer to the same mode.
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If you’re comparing appliances for a larger room or for drying laundry, this model includes Auto and Dry modes. The title lists 20 L/jour, a 40 m² coverage area, Wi-Fi and a 2.5 L tank. Compare these claims with the test conditions and the room you’ll actually use it in. Before using it in a bedroom, ask which mode the 35 dB and 40 dB(A) noise figures refer to.
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This model lets you choose between the stated 3.1 L tank and drainage, if the room has a suitable outlet. The title lists 16 L/jour, four modes, automatic defrost and a 24-hour timer. Ask the retailer to confirm the coverage area for this model before deciding if it’s right for your space: the coverage figures given for the product differ.
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To monitor changes in a room before choosing a dehumidifier, this device displays temperature and humidity, with daily min-max readings and a comfort indicator. It measures humidity but doesn’t remove it or identify its cause. If your decision depends on precise readings, check the stated accuracy.
No. According to ADEME, mechanical ventilation continuously removes moisture from the home, alongside daily airing. A dehumidifier can provide extra support in a room, but it won’t fix faulty ventilation on its own.
If marks appear on the walls, France Rénov’ recommends having their cause investigated. This may involve looking at the walls, the ground, rainwater drainage, insulation and ventilation. A portable appliance isn’t a substitute for this investigation.
Check the litres per 24 h figure and the test conditions stated for each model, then check the operating temperature and intended room. Also compare noise, tank capacity, drainage and useful settings. Capacities measured under different conditions don’t guarantee the same results in your home.
A tank is suitable if you can empty it regularly. A hose for continuous drainage needs a suitable outlet nearby. A pump may be useful if the water needs to be lifted because gravity drainage isn’t suitable. Check the installation requirements in the instructions for your chosen model.