It is evident that the corrosion
rate below 50
%
relative
humidity
(
RH
)
is low
,
and
below
40
%
is negligible
.
The corrosion
rate
increases
significantly above 60
%
RH
.
This
threshold
for
damage
as
the result
of humidity also applies to other
materials
,
such as powdery
substances
,
packaging
,
wood
and electronic
units
.
Buildings may be dried in a variety
of
1
.
By
heating
and air
exchange
:
The air in the room
is
heated in order
for
moisture
to be removed
and
drained
outside
.
All of the energy
that
is involved is lost together with
the moist air that is released
.
2
.
By
air
dehumidification
:
The moist air that is present
within an enclosed space
is continuously dehumidified
according
to
the
condensation
principle
.
The correlations
occurring
when
air is dehumidified are
based
on physical laws
.
These are
depicted
here
in graphical form in order
to provide
you
with
a
brief
overview of the principles of air
dehumidification
.
The use of
AQUA air dehumidifiers
Even if Windows
and
doors
are
well
insulated
,
water
and moisture
are
capable
of penetrating even thick
concrete
walls
.
The water required
for setting in the production
of concrete
,
mortar
and
plaster
etc
.
may only be diffused
after
1
-
2 months
.
Even moisture
trapped
in the masonry after high
-
water or a food is released
very
slowly
.
The same
is
also
true
of moisture
contained in for example stored
materials
.
The moisture
(
water
vapour
)
released
from
parts
of
a building
or materials is absorbed
by the surrounding
air
.
As
a
result
,
the moisture
content
increases
,
which ultimately gives rise
to corrosion
,
mould
,
rot
,
peeling
of paint and other unwanted damage
.
By way of example
,
the diagram
shows the corrosion
rate
of
metal
in different
levels
of
humidity
.
Air dehumidification
With
regard
to
energy
consumption
,
air dehumidification
has one distinct advantage
:
Energy
expenditure
is
limited
exclusively to the air volumes
present
.,
The
mechanical
heat
that
is released
by
the
dehumidification
process
is
fed
back
into
the
room
.
Under
normal
use
,
the
air
dehumidifier
uses
approximately
25
%
of
the
energy
that
is
required
for
the
"
heating
and
ventilating
"
principle
.
Relative humidity
Our ambient air is a gaseous
mixture
which
always
contains
a certain volume of water
in the form of water vapour
.
This volume of water is specified
in g per kg of dry air
(
absolute
moisture
content
).
1m
3
of air weighs approx. 1.2 kg
at 20
°
C
Depending on the temperature
,
each kg of air is only capable
of absorbing a certain volume
of water vapour
.
Once
this
capacity has been reached
,
the
air is referred
to
as
"
saturated
"
and has a relative
humidity
(
RH
)
of 100
%.
Relative humidity is understood
to mean the ratio between
the current
volume
of
water
vapour in
the
air
and
the
maximum
possible volume of water vapour
at the same temperature
.
The ability of the air to absorb
water vapour increases
as the temperature
rises
.
I
.
e
.
the maximum possible
(
absolute
)
water content becomes
greater
as
the
temperature
rises
.
4
Air dehumidifIers
■
■
■
■
c
o
rr
o
si
o
n
r
a
te
Relative humidity%
