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2.4. Antifreeze and preheating
Water condensing from extract air may freeze in the heat recovery cell (4). Freezing can be
prevented by stopping the supply air fan (standard function) or by using a preheating resistor
(see Section 2.4.4.). Both functions are automatic.
Vallox 132 E VKL
Vallox 132 E VKL model includes a water radiator antifreeze thermostat (B). When there is
a risk of freezing in the radiator, the antifreeze thermostat stops both fans and the self-actuated
dampers (5) of the fans close.
2.4.1. Stopping of supply air fan
Antifreeze thermostat (A) of the heat recovery cell stops the supply air fan whenever the
temperature of extract air goes down to circa + 5
°
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.
2.4.2. Antifreeze of post-heating radiator of Vallox 132 E VKL
The VKL model has an antifreeze thermostat (B) for the water radiator and self-actuated
dampers (5) for the fans. When there is a risk of the radiator freezing, the thermostat (B) stops
all functions of the unit and the self-actuated dampers of the fans close at the same time. This
happens when the temperature of the water radiator is lower than the value set at the
thermostat. As soon as the temperature of the radiator has risen, the unit automatically restarts
and the dampers open. The thermostat has been factory set to stop at circa +5
°
C and to
restart at +10
°
C.
2.4.3. Preheating
Vallox 132 E comes standard with a preheating radiator (2).
The factory-preset setpoint of the
preheating radiator thermostat is 0
°
C, i.e. it is not used.
A separate thermostat (C) for preheating
measures the temperature of exhaust air. The preheating radiator switches on when exhaust
air temperature goes below the setpoint of the thermostat. If exhaust air temperature continues
to go down, the antifreeze thermostat (A) of the HR cell of Vallox 132 E stops the supply air
fan. The preheating resistor (2) switches off when exhaust air temperature is by circa 3
°
C
higher than the value set for the thermostat.
Note! You can adjust the antifreeze thermostats (C and A) for Vallox 132 E preheating radiator and
HR cell. However, observe the following things:
Taking preheating into use and adjusting it
If you wish to use the preheating radiator, the recommended setting for the thermostat (C)
is circa +5
°
C...+ 10
°
C, but in any case a little higher than the setting for the HR cell
antifreeze thermostat (A) of Vallox 132 E. In this case the preheating resistor will become
active before the fan stops, which means that preheating is truly beneficial.
Instructions for antifreeze thermostat adjustment
• You may check how antifreeze works by comparing the functioning of the supply air fan
and the preheating radiator. If the fan stops before the preheating radiator (2) switches
on to heat, you have to adjust the HR cell antifreeze thermostat (A) somewhat lower, from
+5
°
C to +3
°
C for example. Alternatively, you may increase the setting for the thermostat
(C) of the preheating radiator.
• Observe the difference in how the thermostats function. The scales in the thermostats
indicate the temperature in which they switch on. In other words, the supply air fan of
Vallox 132 E stops at a temperature that is circa 3 … 5
°
C cooler than the scale indicates.
• The preheating radiator heats even if the supply air fan is stopped. Consequently,
underpressure causes air coming from the outside to become warmer before the cell,
shortening the time during which the fan is stopped.
VALLOX 132 E/VKL
A
C
B
6
INSTRUCTIONS FOR USE
© VALLOX • We reserve the right to make changes without prior notification
Connection box cover plate
1
2
Vallox 132E R
Vallox 132 E VKL R
4
5
3
Thermostats (behind cover plate)
Vallox 132 E thermostats
(electric post-heating radiator)
A Antifreeze thermostat of heat
recovery cell
B Post-heating
thermostat
(regulation of supply air
temperature)
C Preheating
thermostat
Vallox 132 E VKL thermostats
(water-circulating post-heating
radiator)
A Antifreeze thermostat of heat
recovery cell
B Post-heating
antifreeze
thermostat
C Preheating
thermostat
Summary of Contents for 132 E Series
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