enervent Svea eAir - Functional Description

23Installation instructions for professionals
rst rotating heat exchanger. This procedure signicantly
reduces the energy need foor cooling in hot and humid
conditions.
Fans
When electricity is connected to the ventilation unit, the
damper control relay activates and heat recovery starts
at maximum eciency. Extract air fan will turn on in a
moment, after which the supply air fan will turn on after
a small delay. After this the ventilation unit will function
based on the congured settings.
Fans operate at speeds set by the active mode. Fan speeds
(or duct pressures) are congured for each mode during
commissioning. Supply and extract fans both have their
separate speed settings.
The modes aecting the fan speeds are:
• At home (Oce)
• RH%, CO2, or temperature boost
• Away
• Summer night cooling
• Manual boost
• Overpressure, cooking hood and central vacuum
cleaner modes
• Alarm modes A and AB
• Silent mode
• Max. heating/cooling
The speed of supply and exhaust fans are set for each
mode, except for alarm modes, in which the fans are
always stopped or operating at minimum fan speed.
Constant duct pressure control
Constant duct pressure control is an alternative for xed
fan speeds. When using constant duct pressure control,
instead of a xed fan speed, each mode is given a xed
pressure dierence that the automation will try to
maintain.
The ventilation unit motherboard need to have two 0–10
V / 24 V dierential pressure transmitters (accessory)
connected. They measure the dierential pressure of the
supply and extract duct in comparison to the surrounding
air. Dierential pressures are maintained at target values
by changing fan speeds. Constant air volume is controlled
if dierential pressure is measured over an iris damper.
Functional description
Operating environments
The operating environments for the ventilation unit are
Home, Oce, VAK1, VAK2, and VAK3.
The functions available dier based on the operating
environment.
• The unit operates constantly in the Home operating
environment. This is the default setting
• In the Oce operating environment, the unit operates
based on a timer program or an external control. The
Oce mode can be activated from the control panel.
• VAK1, 2, and 3 operating environments are meant for
large properties, where the unit is operating as a part
of a SCADA control system. The unit operates only on
external commands. VAK operation environment can
be preset at the factory in advance, if necessary.
TCG units
TCG ventilation units are ventilation units intended for
special use. Their cooling and dehumidifying capabilities
are more ecient. The cooling and dehumidifying
capabilities of the TCG units are accomplished by
circulating cool liquid, either plain water or water solution
containing antifreeze. The unit is used in the same way
as CG (Cooling Geo) ventilation units. The same liquid
can be used, but the eectiveness of the TCG unit’s
cooling and dehumidifying is better than in ventilation
units with regular cooling. In TCG-units the rotating heat
exchanger is used for both cooling and dehumidifying.
eAir automation controls cooling and dehumidifying fully
automatically based on the temperature and humidity
limits set by the user.
Twin Tropic units
Twin Tropic ventilation units are ventilation units
designed for special use. Their twin rotating heat
exchangers guarantee very ecient dehumidifying and
cooling. The rst rotating heat exchanger pre-cools and
dehumidies the incoming air before cooling and further
dehumidifying the incoming air in the cooling coil. After
this the supply air is heated to the desired temperature
with another rotating heat exchanger, which gets its
heating energy from the warm extract air, which in turn
pre-cools and pre-dehumidies the outdoor air in the