Air always contains a certain amount of water in the air in the form of water vapour.
This amount of moisture is commonly known as the humidity.
The capacity of the air to hold water vapour increases with the temperature. This is why in our
homes, as soon as the temperature decreases, the vapour contained in the air condenses, as
is evident on the colder surfaces in the room, such as the windows, walls etc.
The purpose of a dehumidifier is to remove the excess moisture from the air, to control
condensation within the home.
Experts have established that the optimum environmental conditions for our well being and
preserve objects are obtained between 40% and 60% relative humidity. Below these levels the
air can feel too dry and may cause skin complaints and even static electric shocks.
If temperatures in the home are lower than 10°C for prolonged periods low level heating will
be necessary to allow the condensate to evaporate into the air before dehumidification can
take place. The air will however be slightly warmed by the dehumidifier as the dry air leaving
the dehumidifier is about 1°C higher than normal room temperature.
Brief notes on humidity