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© Airflow • We reserve the right to make changes without prior notice.
What the units include can vary depending on the sales area.
OPERATING INSTRUCTIONS
Adjustment of supply air temperature
and summer/winter function
The temperature of air coming to the dwelling can be adjusted
between circa +10 °C and +30 °C. When there is a light on the
post-heating indicator, post-heating is activated and the unit heats air
as needed. The need for heating depends on the setpoint of supply
air temperature.
When there is no light on the post-heating indicator, post-heating is
off. This means that the summer function is activated for the ventilation
unit. The unit has a motorised summer/winter function. When the
summer function is on, the heat recovery cell is bypassed as soon
as outdoor air temperature has risen above the setpoint. See the
setpoint for cell bypass, factory s12 ºC. When outdoor air
temperature goes below the setpoint (factory s12 °C), the
unit starts to recover heat.
Two different kinds of supply air temperature adjustment can be
chosen at the unit: constant temperature control or cascade control.
In constant temperature control, the unit controls the temperature of
supply air directly in accordance with the measurement information
on the temperature of supply air blown to the ventilation area. In
cascade control, the unit controls supply air temperature according
to the temperature of air extracted from the ventilation area. The unit
calculates the difference between the air extracted and the setpoint
for supply air and uses this difference to control the need for post-
heating.
Winter function of ventilation unit
A set of parameters has been set at the factory for the freezing of
the heat recovery cell (3.21 and 3.22).When these parameters are
undercut, the ventilation unit melts the heat recovery cell utilising the
heat of extract air.
Melting is done by stopping the supply air fan (3.20. Choosing
melting mode) or by bypassing the heat recovery cell on the supply
air side (factory setting).
If the bypassing the heat recovery cell is chosen as the melting
mode, the relationship between the supply and extract air fl ows
does not change. This prevents the formation of a vacuum inside,
which may be harmful in some cases. In this case the electric resistor
heats the cold air coming from outside during the melting period to
Remember!
Switch post-heating off when it starts to get too warm in the
dwelling because of warm weathers.
Switch post-heating on again when it gets cooler in autumn.
Post-heating indicator light
Maintenance reminder
symbol
Maintenance reminder
• The maintenance reminder switches on the maintenance
reminder symbol( ) on the main display of the control panel
at defi ned intervals, the factory setting being 4 months.
• The maintenance reminder symbol is acknowledged at
the main display of the control panel. (See the operating
instructions for control panel, Section 3.1.)
• The interval can be set between 1 and 15 months at the
control panel.
Fireplace switch function/booster
Fireplace switch function
(See the operating instructions for control panel, Section 3.12.)
• The fi replace switch stops the extract air fan for 15 minutes and
produces overpressure in the ventilation zone. This makes it
easier to light a fi replace.
The function is started on the main display of the control panel
by simultaneously pressing and holding down the + and –
buttons for 2 seconds.
• The function can also be started at a separate auto-reset push-
button switch, wired from the connection box of the unit for
example to a wall in the fi replace room. Upon each pressing,
the stopping function continues for 15 minutes (the switch is not
included in the delivery).
• During the function, the fi replace/booster switch symbol ( ) is
visible on the main display of the control panel.
NOTE! The starting of the extract air fan may weaken draught in the
fi replace! In winter, this situation may disturb the winter function of the
unit. The situation will normalise in a while, after the fi replace function
stops.
Booster switch function
(See the operating instructions for control panel, Section 3.12.)
• The booster switch function raises fan speed to the set maximum
fan speed for 45 minutes.
The function is started on the main display of the control panel
by simultaneously pressing and holding down the + and –
buttons for 2 seconds.
• The function can also be started at a separate auto-reset
push-button switch, wired from the connection box of the unit
to for instance a wall in a classroom. Upon each pressing, the
boosting function continues for 45 minutes.
• During the function, the fi replace/booster switch symbol ( ) is
visible in the main display of the control panel.
• The function is chosen at the control panel.
Fireplace/booster switch symbol
Fault signal relay (remote monitoring)
• The fault signal relay has potential-free contacts
(24 VDC, 1 A).
• The contacts provide information on various failure modes
of the unit.
• Alarm of high carbon dioxide content switches the relay at
1-second intervals.
• In other fault situations, the contacts are closed.
the temperature desired (2.6. Setting supply air temperature). If the
temperature desired is high compared to outdoor air temperature,
the unit decreases the supply and extract air fl ows in order to attain
the desired supply air temperature.
A normal melting period varies from 15 to 45 minutes depending on
the amount of ice and the volume of the extract air fl ow.
The unit operates optimally on the factory settings in normal operation
in dwellings and detached houses. The parameters only need to be
touched in extreme problem situations. Examples of such situations
are high humidity loads such as a swimming pool or if there is a
detrimental amount of ice in the exhaust air duct.
DV145SE
