FRÄNKISCHE profi-air 250/360 flex, Installation And Operating Instructions Manual

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Installation and operating instructions profi-air 250/360 flex
72
A frost protection strategy is integrated into
the control in order to prevent ice formation
in the heat exchanger. The following meas-
ures will be taken if the fresh air tempera-
ture (T1) falls below –4 °C and the exhaust
air temperature (T4) is below 8 °C:
n
The speed of the supply air fan decreases by 3 rev./second until the mini-
mum speed is reached.
n
After 10 seconds in minimum speed, the supply air fan stops completely
while the exhaust air fan feeds warm air into the heat exchanger to
defrost potential icing.
n
When the exhaust air temperature (T4) increases to above 8 °C again, the
supply air fan increases its speed by 3 rev./second until the original value
is reached.
n
If the exhaust air temperature (T4) falls below 2 °C, the supply air fan will
again reduce its speed.
n
If the fresh air temperature (T1) falls below –13 °C for more than 5 min-
utes, even in case of activated defrosting mode, the device will stop
operation for 30 minutes. This sleep mode will be deactivated if an elec-
tric defroster heater is used.
6.4 Frost protection of the heat exchanger
6.4.1 Frost protection of the heat exchanger without defroster heater
If the profi-air flex ventilation unit and a fireplace are operated at the same time, this frost protection
strategy cannot be selected, since negative pressure may occur in the installation room in the event of
frost protection.
If the profi-air flex ventilation unit and a room air-dependent fireplace are operated at the same time, it
is recommended to use defroster heater. In addition to this, the operation with a fireplace shall be set
with the help of profi-air cockpit pro software.
If the profi-air flex ventilation unit and a fireplace are operated at the same time, the district master
chimney sweep should always be contacted in advance in order to decide if safety pressure monitoring
must be installed. This system is then connected to the network supply line of the ventilation unit.
6.4.2 Frost protection of the heat exchanger with defroster heater
If a profi-air defroster heater has been
installed, it adds electric heat to the inflow-
ing fresh air (T1) to ensure frost protection
and increase the supply air temperature (T2).
The defroster heater is controlled as follows:
n
If the fresh air temperature (T1) is below –3 °C or the supply air is below
16.5 °C, the ventilation unit will engage the defroster heater with 10 %
performance.
n
This increases or decreases by 10 % every 60 seconds depending on the
fresh air (T1) and supply air temperature (T2).
The defroster heater must be activated using the profi-air cockpit pro software or the wireless remote
control since the ventilation unit otherwise remains in frost protection mode without defroster heater.
If the profi-air flex ventilation unit and a room air-dependent fireplace are operated at the same time, it
is recommended to use defroster heater. In addition to this, the operation with a fireplace shall be set
with the help of profi-air cockpit pro software.
If the profi-air flex ventilation unit and a fireplace are operated at the same time, the district master
chimney sweep should always be contacted in advance in order to decide if safety pressure monitoring
must be installed. This system is then connected to the network supply line of the ventilation unit.