VALLOX DIGIT SE/SE VKL
6
INSTRUCTIONS FOR USE
Remember:
Switch post-heating off when it gets
too warm in the dwelling. Switch post-
heating on again when it gets cooler in
autumn.
2.9. Supply air constant temperature control
• In DIGIT SE, post-heating control is proportional: when the chosen temperature exceeds
supply air temperature by more than 2.5
°
C, the radiator is on 100% of the time; when the
temperature differential gets smaller, the on time of the radiator is reduced automatically in
two-minute sequences. The temperature range is 10…30
°
C.
• The heating radiator is on when the -sign is displayed.
• Temperature control is only active when post-heating has been switched on.
2.10. Supply air cascade control
• Supply air temperature control can be replaced with cascade control.
• Cascade control changes the mode of regulating the post-heating radiator: the temperature of
air blown to the ventilation zone is controlled on the basis of extract air.
• The program aims at keeping supply air temperature at the value that depends on the
difference between extract air and the setpoint as follows: if extract air is hotter than the
setpoint, the temperature of supply air is lower than the setpoint by the same amount. If extract
air is cooler than the setpoint, supply air is hotter by the same amount. For instance, if indoor
air temperature is 25
°
C and the setpoint is 24
°
C, the aim is to blow 23
°
C air to the ventilation
zone. If the temperature in the ventilation zone is 24
°
C and the setpoint is 25
°
C, the aim is to
blow 26
°
C air to the ventilation zone.
• The aim is to permanently keep the temperature of air blown to the ventilation zone within the
range 10...30
°
C.
• Cascade control can be chosen on the control panel, and it is active when post-heating has
been switched on.
• The heating radiator is on when the -sign is displayed.
2.11. Heat recovery bypass
• The aim of the heat recovery bypass function is to ensure that supply air coming to the
ventilation zone is as cool as possible. To do this, the heat recovery bypass function compares
the measurement data of the outdoor and extract air sensors.
• The heat recovery cell is bypassed, when the post-heating function is off, when outdoor air
temperature exceeds two degrees the setpoint and when extract air is hotter than outdoor air.
• The setpoint can be changed between 0…+25
°
C. (Factory setting 10
°
C).
2.12. Heat recovery defrost function and preheating
• Defrost prevents the heat recovery cell from freezing, thus ensuring proper ventilation even in
cold periods.
• In a standard ventilation unit, defrosting is implemented by intermittently stopping the supply
air fan. The stopping function is controlled on the basis of the measurement data given by the
temperature sensor that measures the temperature of exhaust air after the heat recovery cell.
• The supply air fan stops when exhaust air temperature falls to the setpoint (factory setting
+4
°
C) and starts when exhaust air temperature has risen to the value set (hysteresis setting,
factory s3
°
C).
Preheating
• The system can also be equipped with an optional preheating facility. The preheating radiator
(A) has been installed in the outdoor air duct (B). It is switched on before the supply air fan
stops. The operation is controlled by the same sensor that has been installed in exhaust air.
The heater is switched on at a temperature higher than the stopping temperature (factory
s6
°
C). If preheating cannot keep exhaust air temperature warmer than the stopping
temperature, the outdoor air fan stops. When the risk of freezing has passed, preheating is
switched off and the supply air fan starts automatically.
• Post-heating is on throughout the freezing risk period.
2.13. Maintenance reminder
• The maintenance reminder switches on the maintenance reminder symbol ( ) in the main
display of the control panel at defined intervals, the factory setting being 4 months.
• The maintenance reminder symbol is acknowledged at the control panel (see the instructions
for using the control panel, Section 3.3.10.).
• The interval can be set between 1...15 months at the control panel.
A
B
© VALLOX • We reserve the right to make changes without prior notification.
Preheating
