Cooling Via Geothermal Heat Exchanger - Viessmann VITOTRONIC 200 Service Instructions Manual

Mechanical ventilation with Vitovent...

Cooling via geothermal heat exchanger

The outdoor air can be routed through a geothermal
heat exchanger (on site), regardless of the position of
the bypass damper integrated into the ventilation unit.
This causes the outdoor air to cool down in the ground
during the warmer months.
If the outdoor air exceeds "Max. temperature, geo-
thermal heat exchanger C1AB", the 3-way diverter
damper (on site) opens up the path through the geo-
thermal heat exchanger. Below this temperature the
outdoor air flows directly into the ventilation unit
uncooled.
Frost protection with factory-fitted electric preheating coil
The ventilation units are factory-fitted with an electric
preheating coil.
The factory-fitted electric preheating coil is switched on
if the outside temperature falls below
than 5 min. With the Vitovent 300-W, the pressure in
the exhaust air duct is also monitored as an additional
activation condition.
The output of the factory-fitted electric preheating coil
is controlled so that the following outside air tempera-
tures are achieved:
■ Vitovent 200-W: 0 °C
■ Vitovent 300-C: 4 °C
■ Vitovent 300-W: 1.5 °C
–
If the relevant outdoor air temperature is not reached
with max. heating output, the air flow rate is addition-
ally reduced to protect the heat exchanger.
■ Pressure imbalance is permitted ("Specified imbal-
ance C1A3" set to "1"):
Only the supply air flow rate is reduced.
Pressure imbalance is not permitted ("Specified
■
imbalance C1A3" set to "0"):
Supply air and extract air flow rate are reduced.
Frost protection with additional electric preheating coil
The additional electric preheating coil (accessories) is
installed in the outdoor air duct.
If the output of the factory-fitted preheating coil is not
sufficient for reaching the relevant outdoor air tempera-
ture ( 1.5 °C, 0 °C, 4 °C) , the additional electric pre-
–
heating coil is switched on. The air flow rate is only
reduced if the heating output of both preheating coils
combined is insufficient.
Frost protection with geothermal heat exchanger
For preheating, the outdoor air can be routed through
a geothermal heat exchanger (on site).
(cont.)
Required enable, 3-way diverter damper (on site)
Parameter
"Preheating coil C101"
Requirement: No additional electric preheating coil is
installed in the outdoor air duct: See the following
chapter.
1.5 °C for more
–
End of frost protection function
If outdoor air temperatures are above
flow rate is initially raised back up to the original value
in increments. Subsequently the output of the electric
preheating coil is reduced, and if no longer required
the preheating coil is switched off.
Enable required
Parameter
"Preheating coil C101"
End of frost protection function
See chapter "Frost protection with factory-fitted electric
preheating coil".
Function description
Setting
"65" or "81"
1.5 °C the air
–
Setting
"17" or "81"
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