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HUMIDITY-CONTROLLED OPERATION OF THE UNIT
If the humidity sensor detects the indoor humidity above the set point, the unit automatically switches to the extract mode.
The humidity sensor for the ventilation unit with the control panel A11 and A19 is integrated in the control panel. Optionally
the humidity sensor may be integrated into the extract air duct. The duct humidity sensor is not included in the delivery set and
is available as a specially ordered accessory. It must be installed independently.
To select the main humidity sensor for the ventilation unit with A11 or A19 control panels, please refer to the user's
ma nual fo r th e re spec t i ve co nt ro l pa nel, open "Engineering me nu ", s el ec t " E x tra options" a nd go to "HUM ID IT Y SE NSOR SELEC TION".
Select 1 for the room humidity sensor integrated in the control panel.
Select 2 for the humidity sensor in the air duct.
Activate AUTO mode to enable automatic operation of the unit on feedback from the set humidity sensor. In AUTO mode the
unit switches to the higher speed if the extract air humidity reaches the set humidity point.The unit switches to lower speed after
indoor humidity drops down below the set point. The maximum speed is 100% and the minimum speed is 25% in the AUTO mode.
The ventilation unit with A14 control panel switches to the higher speed up to 100 % if the extract air humidity reaches the
set humidity point. The unit switches to lower speed after indoor humidity drops down below the set point.
UNIT OPERATION MODES
Some modifications of the unit are equipped with a bypass duct and bypass air damper. The electrically actuated bypass air
damper opens or closes the bypass duct, depending on operation modes. The air flowing through the bypass damper does not
come in contact with the heat exchanger. When the bypass damper is closed, the intake air flows through the heat exchanger.
Heat recovery mode
Warm extract air from the room flows into the unit and is cleaned in the extract filter. Then the air is moved through the heat
exchanger and is exhausted outside with the extract fan.
Cold fresh air from outside flows into the unit, where it is cleaned in the supply filter. Then the air flows through the heat
exchanger and is moved to the room with the supply fan.
Supply air is heated in the heat exchanger by transferring the heat energy of warm and humid extract air to the cold fresh air.
The air flows are fully separated while flowing through the heat exchanger. Heat recovery minimizes heat losses, which reduces
the cost of space heating in the cold season.
Freeze protection mode
Defrosting mode is actuated on feedback from the freeze protection temperature sensor to enable the heat exchanger freeze
protection in the cold season. The freeze protection temperature sensor is located in the exhaust air duct. The freeze protection
operation mode is activated when the exhaust air temperature falls down to +3 °C. The unit reverts to the previous operation
mode after the temperature increase.
To activate the freeze protection mode for the ventilation unit with A11 or A19 control panel, please refer to the user's
manual for the respective control panel, open "Engineering menu", select "Extra options". To activate the freeze protection mode
select the required option, suitable for the ventilation unit model and edit its current status:
• For the ventilation units with a bypass damper select "BYPASS OPERATION MODES" and select "ON".
• For the ventilation units without a heater select "SUPPLY FAN OFF" and select "ON".
• For the ventilation units with integrated heater(s) select "HEATING CONTROL" and select "ON".
For the ventilation units with A14 control panel the freeze protection mode is activated automatically by turning off the
supply fan, hence no activation is required.
Summer cooling mode
The extract air flows through the bypass duct and does not come in contact with the heat exchanger. The bypass duct is
opened with a bypass damper. The temperature of the air is not changed after passing through the heat exchanger.
