An electric heater does not remove moisture from the air, but the relative humidity does drop as soon as the room gets warmer. This is because warm air can hold more moisture. As a result, the air feels drier, while the amount of water vapor in the room remains the same.
Direct answer: a heater does not remove moisture from the air, but lowers the relative humidity because the temperature rises.
What happens to the humidity when the room warms up?
Relative humidity indicates how much moisture is in the air compared to the maximum at that temperature. Warm air can hold more moisture than cold air. If you heat a room while the amount of water vapor remains the same, the percentage drops. So it is not a matter of a heater drying out the air: it is about what the meter shows and what you feel. You can find more about this connection in why the air in the house is dry in winter.
Why does the air still feel drier near a heater?
A heater blows warm air or radiates heat. You feel the direct heat, and the air near the device is warmer and therefore relatively drier. Even if you stay longer in a heated, closed room, the air can feel drier than in a room that is not heated. This difference is especially noticeable in winter, when the outside air already contains little moisture.
What can you do about it?
Start by measuring. With a hygrometer you can see how dry the air really is, so you do not have to guess by feel. Then ventilate in a way that does not cost too much heat; tips are available in how to ventilate in winter without losing much heat. A bowl of water near the heater is often recommended, but whether that really helps you can read in is a bowl of water near the heater effective. If you regularly suffer from dry air, you can consider using a humidifier; humidifier or dehumidifier: how to choose will help you with that.
Overview: what changes with a heater?
| What | Does it change? | Explanation |
|---|---|---|
| Amount of water vapor | Hardly | A heater does not remove moisture |
| Temperature | Rises | The room gets warmer |
| Relative humidity | Drops | Warm air can hold more moisture |
| Feeling of dryness | Can increase | Especially in a closed room |
Dynter HW2002 electric heater
The Dynter AirFlow HW2002 electric heater is suitable for spaces up to 40 m².
Power: 1500 - 2000 W adjustable
Temperature: 15°C to 45°C adjustable
Rotating function: for even heat distribution
Controls: LCD touchscreen and remote control
Timer: automatic shut-off
Safety: overheating protection and fall detection
If you prefer to choose another auxiliary heater, take a look at the Dynter heater collection. A properly set device helps to avoid heating your room unnecessarily hot, which also limits the relative dryness. If you want to know what the power consumption is, read what an electric heater costs per hour.
Frequently asked questions
Does a heater really dry out the air?
Not in the sense that moisture disappears. The relative humidity drops because the air gets warmer.
Is a lower setting better for the humidity?
A lower setting heats less, so the relative humidity drops less. Set the temperature to what you find comfortable.
Does a bowl of water next to the heater help?
The effect is usually limited. Never place a bowl of water on or right next to an electrical device.
How do I measure the humidity?
With a hygrometer, which you can buy for a few euros. Do not place it right next to the heater.
When is a humidifier useful?
If the meter consistently shows low humidity and you experience that as uncomfortable.