5
W9
Smart
All rights to changes reserved.
2021-09-23
• The ventilation unit cannot cool the supply air with-
out an air cooler (duct coil), which is available as an
accessory.
In the Econo models, the setpoint can be set with
a thermostat inside the ventilation unit. You can
turn the thermostat dial to the minimum setting if
heating is not required.
W9’s intelligent summer function helps to maintain the
home’s indoor air comfort even during hot summer
days. Very economical comfort coolness can be pro-
duced almost free of charge by utilising the difference
between indoor and outdoor temperatures and the
heat exchanger intelligently. The heat exchanger takes
care of the cool indoor air during hot summer days and
cools the incoming outdoor air. At night the air passes
the heat exchanger and the home is cooled with fresh
outdoor air. This is managed by an advanced automatic
system.
1.6 Protective functions
The heat exchanger’s freeze protection
W9’s defrosting function guarantees continuous and
balanced ventilation in the home even during extreme
conditions. If there is a risk of the heat exchanger in
the ventilation unit freezing, the preheater is activated
and the speed of the fans is changed and in doing so
the heated extract air prevents freezing inside the heat
exchanger.
The fans’ overheating protection
The fans have thermal overload cut-outs, which stop
them if the temperature rises too high. The controller
also stops the fans if a serious malfunction occurs in the
ventilation unit. The protective function resets itself au-
tomatically when the temperature drops or the malfunc-
tion has been remedied.
Electric air heater
The electric air heater is equipped with overtemperature
protection. If the overtemperature protection trips, you
must not continue to use the ventilation unit until the
cause of the overtemperature protection tripping has
been established and the fault has been rectified.
An automatic overtemperature protection switches off
the air heater if a fault situation arises. This protective
device automatically resets itself when the air heater has
cooled down.
The thermal overload cut out with manual reset can be
reset by pressing a button inside the ventilation unit. The
acknowledgement buttons are located next to the air
heaters. The buttons are marked in the illustrations below.
When you press the reset buttons and feel a click, the
overtemperature protection (thermal overload cut out) has
then been reset.
Ventilation unit with water-heated air heater
The ventilation unit with water-heated air heater has a
temperature sensor that protects the air heater from freez-
ing. The air heater freezing warning alarm appears on the
screen if the temperature of the water heated air heater
drops too low, but the unit continues to operate normally.
If the air heater’s temperature drops further, the control-
ler will stop the ventilation unit to prevent the air heater
from freezing. An alarm is then shown on the cooker
hood.
When the temperature of the air heater has risen suf-
ficiently, the ventilation unit and panel show a so-called
remaining info-alarm, . The Info alarm can be reset
from “Alarm” on the main menu.
Cold supply air
The ventilation unit has built-in condensation protection
on the ventilation duct. If it is discovered that the supply
air is too cold, the ventilation unit stops and an alarm is
shown the cooker hood.
Temperature sensors
If a sensor fault is detected, the ventilation unit enters
restricted mode to prevent damage to the ventilation
unit. The functions related to the current sensor in ques-
tion are deactivated and the ventilation unit works as
well as possible. The ventilation unit’s function returns
to normal once the fault has been corrected.
