VALLOX 70
6
INSTRUCTIONS FOR USE
2.4. Air Filtration
VALLOX 70 features both discharge and supply air filtration before the fans and the heat
recovery cell. The unit comes standard with an EU7 fine filter that filters fine dust, pollen and
dust not discernible to the eye, as well as an EU1 coarse filter for insects, coarse pollen and
dust. The filters have to be in the unit whenever ventilation is operating.
2.5. Defrosting
Water condensing from discharge air may freeze in the heat recovery cell. Defrosting can
be prevented by stopping the supply air fan (standard), or by turning on the preheating
resistor (optional). Both functions are automatic.
2.5.1. Stopping the Supply Air Fan
The defrosting thermostat (item 13 in the parts list on page 3) stops the supply air fan when
discharge air temperature falls to approxi5
°
C. The fan restarts when temperature
has risen by three degrees, i.e. to +8
°
C. The threshold value of the thermostat can be adjusted.
2.5.2. Outdoor Air Preheating (optional)
VALLOX 70 can be equipped with an optional preheater (installed at the factory). The
defrosting thermostat turns the heater on instead of stopping the outdoor air fan. The heater
heats outdoor air before it reaches the cell, preventing it from freezing. At very low temperatures,
the 1000W radiator is not enough for heating maximum air flow (at -30 ˚C, max air flow
is 30dm
3
/s, corresponding to speed 2 or 3).
The threshold values of the defrosting thermostat can be adjusted inside the unit.
2.5.3. Post-heating of Outdoor Air
The operation of the radiator is controlled inside VALLOX 70. The adjustment
range is +10...+25
°
C.
2.5.4. Heat Recovery Bypass (optional)
VALLOX 70 can be equipped with an optional summer cell that is installed in place of the
heat recovery cell for the summer. The summer cell lets in fresh outdoor air without
discharge air heating outdoor air.
Summer cell for VALLOX 70 units
2
1
Defrosting starts to work
Temperature of supply air going to the
house from VALLOX 70
Temperature of outdoor air coming to VALLOX 70
˚C
max
25
20
10
0
-30
-20
-10
-0
10
20
˚C
1. Supply air heated by
discharge air
2. Maximum temperature
• 500W post-heating radiator
can heat air flowing at 50
dm
3
/s by approximately
8 ˚C.
• The temperature of outdoor air
coming to the unit is 20 ˚C.
The effect of outdoor air flow
and temperature on supply air
Figure 2.5.3. Operation of the
post-heating radiator
