OPERATING AND INSTALLATION INSTRUCTIONS LG 250 A
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In principle: “Ventilate as much as
necessary”
Adjustment of air volume requires
relevant expertise and is performed by a
specialist during initial start-up.
If ventilation is too low, poor ambient air
quality or mould formation may result in
living areas.
If ventilation is too high, ambient air may
become too dry - particularly in the colder
months.
Superior air volume control
There are various configurations and op-
erating modes that result in your ventila-
tion unit being operated with air volumes
other than those set.
These include:
CO
2
concentration-based control (Figure1)
Acceptable room air should not exceed
a CO
2
value of 1000 ppm, meaning that
active ventilation should take place every
1 to 2 hours. A living room ventilation
unit with CO
2
concentration-based control
(CO
2
sensor module available as part of
the accessories) automatically ensures
that a defined CO
2
value of 900 ppm is not
exceeded.
Humidity concentration-based control
(Figure2)
The relative humidity is a factor that also
contributes significantly to a comfortable
living climate. Acceptable humidity is
defined by a comfort window.
In the case of a ventilation unit with
humidity concentration-based control
(RH sensor module available as part of
the accessories), a permanently defined
relative humidity setpoint of 65 %
is stored.
If this value is exceeded, the ventilation
unit switches to the
highest fan stage for
60 minutes.
Figure 1: Schematic diagram showing the increase in CO
2
concentration in a fl at/room with occupants with
and without mechanical ventilation.
Decreasing ability
to concentrate,
headache
Closed window
Mech. residential ventilation
Fresh ambient air: 400 ppm
Disruptive
Pleasant
Hours
CO
2
concentration in ppm
Figure 2: Representation of the comfort window as a function of the air temperature and relative humidity.
Constructional ceiling
(condensate, mould, etc.)
approx. 45 % to 55 %
Comfort level for human
beings 20 %
Ideal RH 35 % to 45 %
R
elativ
e humidity (RH) of the ambient air in %
Ambient temperature in °C
Uncomfortably dry
Uncomfortably dry
Comfortable
Still comfortable
