valve at the top of the unit and suck in warm room air.
This warm room air is mixed with the sucked-in cold
outside air.
At the same time, the supply fan starts running faster so
that the amount of fresh outside air remains the same.
Thanks to this preheating of the cold outside air, the
warm air extracted from the dwelling does not have to
warm up the cold fresh air as much. As a result, the
temperature of the exhaust air in the heat exchanger
remains safely above the freezing point.
If the outside temperature drops even further, the supply
fan will slow down until it ultimately reaches a minimum
speed.
If the temperature drops even further, the exhaust fan
speed will be increased and the supply fan will continue
to run at minimum speed. If the outside temperature
becomes extremely low, the supply fan will be switched
off but the exhaust fan will continue running. The frost
valve is also closed in this case.
After a defined time, the supply fan will start running
again at minimum speed and the frost valve will be
opened again to check whether the frost risk has gone
away. If the outside temperature rises, the above actions
occur in the reverse order until the frost risk is gone. The
resident always determines the exhaust air volume.
2.4.3. Automatic ventilation based on
CO2 measurement
A wireless CO
2
sensor can be connected to the
ventilation unit.
To ensure a healthy indoor climate and to prevent the air
in the dwelling from becoming stale, it is important that
the the CO2-level is not too high.
The sensor can be placed in any room (except the
bathroom), but should preferably be placed in the living
room or bedroom.
The CO2-sensor measures the CO2-level in the room. It
translates the measured value into a ventilation demand
and communicates this via wireless to the ventilation unit
with which it is paired. This allows ventilation to be
continuously and automatically adjusted, and it ensures
that a good indoor climate is achieved in the most
effective and energy efficient manner.
When the the CO2-level has fallen sufficiently, the
capacity of the ventilation unit is automatically decreased.
Tip
It is possible to place several wireless sensors and
controls in the dwelling, up to a maximum of 20.
2.4.4. Automatic ventilation based on
RH measurement
A wireless RH sensor can be connected to the ventilation
unit.
To ensure a healthy indoor climate and to prevent
patches of damp and mould in the dwelling, it is
important that the relative humidity does not stay high for
too long.
The sensor can be placed in any room as desired, but
preferably in a room where a lot of moisture is produced,
such as a bathroom.
The RV-sensor measures the relative humidity in the
room. The sensor translates the measured value into a
ventilation demand and communicates this via wireless to
the ventilation unit paired with the sensor. This allows
ventilation to be continuously and automatically adjusted,
and ensures that a good indoor climate is achieved in the
most effective, energy-efficient manner.
When the relative humidity has fallen sufficiently, the
capacity is automatically decreased.
2.4.5. Automatic ventilation based on
occupancy
A wireless PIR sensor can be connected to the ventilation
unit.
To ensure a healthy indoor climate and to prevent
unpleasant odours in the dwelling, it is important that
there is enough ventilation when people are present.
The sensor can be placed in any room, for example in the
toilet or in a bathroom with a toilet.
The sensor detects the presence (or absence) of people
in the room and communicates this wirelessly to the
ventilation unit with which it is paired.
If the ventilation unit is in Auto mode, the capacity is
continuously and automatically adjusted.
If the sensor detects movement, the ventilation system
runs at increased capacity for a defined period. If the
sensor detects continuous occupancy of the room, the
capacity will be increased even more. If the motion
sensor does not detect any movement within a set
period, the capacity will automatically be decreased
again.
ä
Caution!
Control based on wireless sensors (CO
2
, RV and/or
PIR) only works when the ventilation unit is in Auto or
Auto-Night mode.
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