15
ENGLISH
A
ir in nature always contains a certain quantity of moisture in form of water vapour, and
such quantity determined the humidity level of the air. Nonetheless, the capacity of the air to
hold water vapour is quite limited, and depends on the temperature: the higher the tempera-
ture, the more water can be held in the air.
Absolute humidity (AH)
indicates the quantity of
water vapour contained in 1 kg of air, and is expressed in grams.
Relative humidity (RH)
is the ratio,
in percentage terms, between the quantity of moisture contained in 1 kg of air and the maximum
quantity that the air can hold at such conditions.
Experts have established that the best environmental conditions, both for the human organism
and the conservation of objects, involves a relative humidity of between 45% and 60%.
Consequently, the ambient relative humidity should be maintained within this range. A dehu-
midifier is an appliance that eliminates any excess moisture present in the air
There is also another method used to lower relative humidity, that is, increase the ambient tem-
perature. It is like increasing the capacity of the tank. Therefore, air at 20°C acts like a 10 litre
tank, while air at 30°C acts like a 20 litre tank.
Certainly, increasing the room temperature alone does not provide a solution to the humidity
problem. Heating the air simply maintains the same humidity level suspended in the air in the
form of water vapour. As soon as the temperature decreases again, this water vapour will start
to condense. On the other hand, heating combined with dehumidification (such as in the
combined operation of this dehumidifier) is very useful. Especially at low temperatures, or to dry
the washing. In fact, the heating function transforms the moisture into water vapour that can
be collected by the dehumidifier in an extremely rapid and effective manner. The dehumidi-
fier is therefore the best response to the problems involving excess humidity.
S o m e n o t i o n s o n h u m i d i t y
20°C
5 l
30°C
5 l
U.R. = 50%
U.A. = 5 l
U.R. = 25%
U.A. = 2,5 l
U.R. = 50%
U.A. = 5 l
U.R. = 25%
U.A. = 5 l
2,5 l of moisture
removed
No moisture remo-
ved
20°C
5 l
20°C
2,5 l
5748011200DE350E/GB 21-01-2004 10:49 Pagina 15
