Configuration of the sectional defrosting


Available options & Selection


Sequence selection

Configuration > Functions > Function activation > Heating/Cooling sequence setup

Sequence for exchanger

...| SEQ-B Exchanger |…

Sequence settings

Configuration > Functions > Function activation > Heating/Cooling sequence setup > Exchanger

Type of sequence

... | Exchanger | …

Type of exchanger

| Rotary | Plate | Liquid |

Type of defrosting

...| Sectional defrosting | ...

Defrosting configuration

Configuration > Functions > Temperature control > Sectional defrosting

Temperature sensor

| Defrosting sensor | Exhaust air temperature |

Temperature to monitor

Defrosting constant (B)


Value describing the exchanger's properties

Allow fan stop defrosting if exchanger pressure > max limit

| No | Yes |

Activate fan defrosting (Stop Supply air fan)

Extract air fan speed when fan defrosting

| Auto | Low | Normal | High |

Switch level of the extract air fan if fan defrosting is active

Automatic calibration

| Off | Auto |


Max setpoint deviation extract air fan when auto calibration

[10] %

Manual calibration

| Off | On |

Actual calibration pressure exchanger extract

___ Pa

The latest values of the exchanger's pressure drop / airflow calibration

Calibration flow extract

___ m3/h

Allocate analog inputs

Configuration > I/O allocation settings > Analog inputs

Flow extract air

Any available I/O

Pressure exchanger extract air

PID Settings

Configuration > PID controllers > Defrosting


[16] oC

PID settings for defrosting controller


[240] s


[0] s

Defrost operational settings

Data & Settings > Temperature control > Exchanger > Defrosting pressure monitoring

Setpoint min limit

[-3] oC

Defrosting is enabled when the exhaust air

(or Defrosting) sensor is reading temperature below -3 oC. Defrosting is disabled once temperature exceeds +4 oC.

Hysteresis to end defrosting

[4] oC

Max allowed deviation exchanger pressure when defrosting

[100] %

Activate fan defrosting (Stop Supply air fan) if the pressure drop over exchanger increases more than 100 % of the calibrated value

Max deviation exchanger pressure to start defrosting (SPavf)

[25] %

Defrosting is activated if pressure drop over the heat exchanger is more than 25% higher (compared to the calibrated value) longer than delay time

Hysteresis to end defrosting (SPhys)

[60] %

Defrosting is deactivated at least 60% of the initial exchanger's air permeability is restored longer than the delay time

Delay for pressure limits

[10] s

Delay time for activation and deactivation of the defrosting

Max time in fan stop defrosting mode

[20] min

AL-66 Defrosting alarm is triggered if SAF stop defrosting is active for longer than 20 minutes