Windows that fog up in the morning, the lingering musty smell, dark stains in the corners behind furniture. Excess humidity is noticed first in your eyes before it affects your well-being, but meanwhile, it damages walls, furniture, and the air you breathe. The good news is that in most homes, it can be controlled with a few good habits and, when necessary, with the right device.
What is the right humidity
The ideal relative humidity in a home is between 40% and 60%. Below 40%, the air is too dry and irritates the throat and eyes; above 60%, it promotes mold, dust mites, and condensation. You don’t need to guess: a hygrometer costing just a few euros tells you the real-time value. If you consistently exceed 60%, especially in winter, it’s time to take action before mold appears.
Where does humidity come from
- Everyday activities. Cooking, showering, drying laundry indoors, and even breathing release liters of water vapor into the air every day.
- Poor ventilation. In a sealed and never aired-out home, vapor has no way out and accumulates.
- Thermal bridges. Cold corners and walls cause vapor to condense, and that’s where mold starts.
- Infiltrations and rising damp. Moisture rising from the ground or entering through cracks and the roof: this is structural and must be addressed at the source.
Habits that make a difference
Much can be solved without spending anything, just by changing a few habits.
- Air out every day. Just 5-10 minutes of wide-open windows in the morning is enough to get rid of the night’s vapor. A quick air exchange is better than windows left slightly open for a long time.
- Turn on the extractor fan in the bathroom and kitchen. During and after showering and cooking, to remove vapor right where it forms.
- Don’t dry laundry indoors. A single wet load releases several liters of water into the air as it dries.
- Keep furniture away from cold walls. A few centimeters allow air to circulate and prevent condensation behind them.
When a device is needed
If habits aren’t enough and the hygrometer stays above 60%, a dehumidifier is needed. A model that removes 10-12 liters per day covers a bedroom or a small apartment well; for larger spaces, 20 liters or more is recommended. In summer, an air conditioner in dehumidification mode does the same job while cooling, removing humidity without overcooling. Among the air conditioners and dehumidifiers, you’ll find both solutions, to choose based on the size of the space and the season.
When the problem is structural
If stains always return in the same spot, plaster crumbles, or you feel the wall cold and damp to the touch, it’s not humidity from habits but from the building itself. Thermal bridges, infiltrations, or rising damp cannot be solved with a dehumidifier. In that case, a technical inspection is needed, because just masking the symptoms without removing the cause lets mold return every winter.
Frequently Asked Questions
What humidity levels are normal in a home?
Between 40% and 60% relative humidity. Below 40%, the air is too dry; above 60%, you risk mold and condensation. A hygrometer costing just a few euros lets you monitor the value room by room.
Is a dehumidifier or an air conditioner in dehumidification mode better?
In summer, if you already have an air conditioner, the dehumidification function removes humidity while cooling, convenient and without extra cost. In shoulder seasons or rooms without an air conditioner, a dedicated dehumidifier works better and consumes less.
Is high humidity bad for health?
Above 60%, it promotes mold and dust mites, two common causes of allergies and respiratory problems. Too dry air, below 40%, also irritates the throat and eyes. Staying within the 40-60% range is the best choice for home well-being.