VALLOX DIGIT2 SE
INSTRUCTIONS FOR USE
5
© VALLOX • We reserve the right to make changes without prior notice.
2.3.4.
Liquid-circulating preheating and precooling
• Setting the control temperature (-6
°
C... +15
°
C, outdoor air) for the heating function in a
liquid-circulating preheating unit (MLV model). The function is on when outdoor air
temperature goes below the set temperature and post-heating has been switched on (see
the instructions for using the control panel, Section 3.3.24.).
When the temperature value is lower than the temperature of the liquid coming from the
ground collector, the liquid is used to heat outdoor air. If preheating cannot keep exhaust
air temperature warmer than the stopping temperature is, the outdoor air fan stops.
• Setting the control temperature (+10
°
C... +30
°
C, supply air) for cooling in the liquid-
circulating preheating unit (MLV model). The cooling function starts whe the post-heating
radiator has been switched off and the temperature of air coming from the unit to the
dwelling exceeds the setpoint temperature of supply air (see the instructions for using the
control panel, Section 3.2.6.).
When choosing the setpoint temperature for supply air, care must be taken so as not to
bring too cold air into the duct, which may cause humidity damage. The risk is small when
the ground collectors of the heat pump are situated in the ground or in a water system and
the liquid received from them is warmer in summer than the liquid circulating in the drilled
well.
If the duct is not insulated against condensation indoors, the temperature of air travelling
in it must be confined to below the dew point, which depends on the ambient temperature
and relative humidity. In hot weather, supply air temperature should not go below
+16…+20
°
C.
2.4. Ventilation control with carbon dioxide sensor (option)
• In carbon dioxide control, VALLOX DIGIT2 SE adjusts fan speed so as to keep carbon
dioxide content in the ventilation zone below the setpoint. When two or more sensors are
used, fan speed is adjusted according to the highest measuring result.
• Carbon dioxide control is anticipatory. When carbon dioxide content is on the rise, it
raises speed up to speed 4 even if the setpoint were not exceeded.
• 1...5 carbon dioxide sensors can be connected as options to the VALLOX DIGIT2 SE unit.
• The adjustment is switched on/off and, if needed, the setpoint (500...2000 ppm) is set at
the control panel. The factory setting is 900 ppm. The recommended maximum carbon
dioxide content in good indoor air is 1,000 ppm.
• When control is on, the control panel may be used to raise fan speed to the maximum fan
speed and to decrease it to the base fan speed. In carbon dioxide control, maximum fan
speed limitation is enabled.
2.5. Ventilation control with humidity sensor (option)
There are two methods for adjusting fan speed.
1
Automatic humidity setting
, which is suitable for controlling humidity in washing rooms, for
instance. The program records current humidity level and selects it as the setpoint, which it
then uses as the target for drying air in a bathroom e.g. after a shower. The setpoint
automatically varies according to season, for instance, and is always at the right level.
This setting is factory selected.
2 Humidity level can also be set
fixed
. The setting can range between 1...99 %RH and is set
at the control panel. This can be used in public saunas and swimming pools, for instance.
The program aims at keeping humidity at the setpoint. The setpoint can be changed if
needed.
Mode of adjustment is selected at the controller (see the Settings menu, Section 3.3.19.).
Recommended humidity content of good indoor air is approximately 45%.
• When this control is on, the control panel may be used to raise fan speed to the maximum
fan speed and to decrease it to the base fan speed.
• In humidity control, fan speed varies between the basic and maximum fan speeds
selected.
• When the unit is first taken into use with
automatic setpoint search enabled
(factory setting),
it
takes 3 to 10 hours for the program to define the value
. During this time, humidity adjustment is not
enabled (because the first value, selected at the factory, is 100%).
• Automatic search is enabled even if humidity control is not selected.
Carbon dioxide sensor (CO
2
)
Humidity sensor (RH)
2.4.
2.5.
