Siemens Climatix S300 HRV Application Manual page 93

A6V10733786_en_c
De-icing modes
The de-icing mode can be configured as:
● No de-icing
● Reduce ERC speed to a fix value
● Reduce ERC and fan speed
● Reduce ERC speed and increase preheating
● Reduce ERC speed and fan speed and inrcease preheating
● ERC maintain minimum exhaust temperature
● Maintain exhaust temperature and reduce fan speed
● Maintain exhaust temperature and increase preheating
● Maintain exhaust temperature, reduce fan speed and increase preheating
De-icing with ERC and with preheater are running in parallel. De-icing with fan
speed is running in parallel or with 2 stage, see below.
Time based de-icing started by TEh or TOa
The sensor is not suitable for detecting the end of the de-icing phase. Therefore, a
fix de-icing time is used. After de-icing is finished, an off time is started until the
next de-icing phase can be started again. The duration of the off time depends on
the measured temperature at the start of a de-icing phase. De-icing time, maximum
off time with assigned temperature and minimum off time with assigned
temperature can be configured.
Humidity influence for TEh or TOa
If an extract air humidity sensor is available, the de-icing limit can be lowered,
because icing is reduced due to dry extract air. Configured de-icing limit refers to a
room / extract humidity value of 80% or higher. This value will be reduced
continuously by a configurable temperature drop until the room / extract humidity
value reaches 20% or lower.
De-icing with increased preheating
In case of possible de-icing, brine coil or ground collector are activated by the
outside air conditions. So they automatically assist the de-icing process.
Preheating with electric heater can be used to assist de-icing. This reduces the
efficiency of the heat recovery and uses electrical energy instead.
Especially when no reheating is available, it is recommended to use the electric
preheater, as otherwise reduced heat exchanger function will result in very low
supply air temperature.
As for normal preheating control, TSuAfPreHcl sensor is used. Electrical heater is
modulated to reach SpPreHDeicng setpoint. The preheater control runs in this
mode until de-icing is finished and switches back to normal operation running with
normal setpoint.
De-icing with reduced ERC speed
During de-icing, the speed of the ERC is reduced down to a configurable value.
De-icing with reduced fan speed started by differential pressure
switch
During de-icing fan speed for supply fan and exhaust fan are reduced to
configurable values. For faster de-icing, it is possible to set the supply fan speed
setpoint even to 0%. In this case electric heaters in the supply air are blocked.
Application functionalities
Energy Recovery
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