VALLOX 90 SE
© VALLOX • We reserve the right to make changes without prior notification.
9
HEATING OF OUTDOOR AIR
Preheating
The automatic antifrost function of the heat recovery cells intermittently stops the supply air
fan when the temperature of exhaust air goes under the set threshold value. To avoid or to
decrease the stopping of the supply air fans, supply air can be heated with the preheating
radiator of the unit.
If you wish to use preheating, you must change the setpoint of preheating for the VALLOX 90 SE unit
(see Instructions for use and maintenance, page 10, section 3.3.21).
The preheating radiator is a tubeheater and it is burning hot, when it is in operation.
Using the unit without filters is forbidden. Filters prevent the fans and tubeheaters from getting dirty.
Post-heating radiator
(option)
The post-heating radiator of the VALLOX 90 SE unit is a resistor, which aims at heating the
air blown to the rooms to the preset temperature.
The preheating radiator is a tubeheater and it is burning hot, when it is in operation.
Post-heating adjustment
There are two methods of post-heating
1. Supply air constant temperature control
• Post-heating control used in VALLOX 90 SE is relative; when the temperature selected
exceeds supply air temperature by more than 2.5
°
C, the radiator is on 100 %, and
when the temperature difference gets smaller, the period of active operation is
automatically reduced in two-minute sequences. The adjustment range of heating is
+10...+ 30
°
C.
• The heating radiator is on when the ( ) sign is displayed in the main display of the
control panel.
• The main display of the control panel shows the temperature of supply air.
• Temperature control is only active when post-heating has been switched on.
2. Supply air cascade control
• Supply air temperature control can be changed into cascade control.
• Changes the controlling principle of the post-heating radiator; the temperature of air
blown to the ventilation zone is controlled on the basis of extract air.
• The programme tries to keep supply air temperature at a value determined by the
difference between extract air and the setpoint as follows: If extract air is warmer than
the setpoint, supply air temperature is lower than the setpoint by the difference. If extract
air is colder, supply air is higher than the setpoint by the difference.
If the temperature in the ventilation zone 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 keep the temperature of air blown to the ventilation zone always between
+10...+30
°
C.
• Cascade control can be selected at the control panel, and it is active when post-heating
has been switched on.
• The heating radiator is on when the ( ) sign is displayed in the main display of the
control panel.
