Heat Exchanger Parameters; Exchanger Defrost - Ventair CU24V1 Operation Instruction Manual

4.2.7 H
EAT EXCHANGER PARAMETERS
The ELIM parameter specifies the minimum allowed temperature on the heat exchanger outlet. When
the temperature is below this threshold, the heat exchanger alarm is switched on, the air supply fan is
switched off and the system starts the heat exchanger defrosting cycle.
Default
Name
value
ELIM 5C
4.2.8 E
XCHANGER DEFROST
Defrosting the exchanger is done by running the extract fan at the highest speed for a period of two to
five minutes (depending on the outside temperature), while the inlet fan is stopped. After the defrost
time has elapsed, the extract fan returns to the programmed speed for 20 minutes and the inlet fan
remains off unless the frost alarm goes off.
If after 20 minutes the heat exchanger temperature is still lower than the alarm level, the defrost
procedure will be restarted.
The defrosting procedure ends when the temperature at the exchanger outlet rises above the alarm
level.
The curve representing the defrost time as a function of the outdoor temperature:
Defrost time
5 min
2 min
-10C
Range Description
-10 ÷ +10C Alarm temperature for the heat exchanger
-5C Outdoor temperature
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