22
The unit is equipped with an automatic defrost function that is activated when there is risk of icing in the area around
the heat exchanger.
• Select defrosting mode. Default setting is
Normal
.
Soft
Dry areas, such as warehouse buildings with few people or industrial
buildings that don’t use water in their production process.
Normal
Apartments or houses with normal humidity
1
Hard
Buildings with very high humidity level.
1
In newly constructed houses it might be necessary with a higher defrost level during the first winter period.
• Set by-pass location. Default setting is based on unit configuration.
Supply
/
Extract
.
• Set if secondary air is allowed. Default setting is
Off
.
Off
/
On
.
Cooling Control
• If the outdoor air is warmer than the extract air and the supply air is above the setpoint, cooling recovery occurs. This
condition blocks the heat regulation process. Activate or deactivate cooling recovery. Default setting is
On
.
Set cooling limit. Cooling recovery is allowed if extract air temperature is lower than outdoor air temperature by a set
limit (default setting is 2K) and cooling demand is present.
• Configure status, temperature and duration of free cooling. Activate or deactivate free cooling . Default setting is
Off
.
Set supply and extract air fan levels during free cooling. Default setting is
Normal
. Range:
Normal
/
High
/
Maximum
.
Set start condition. Outdoor daytime temperature for activation, default setting is 22°C. Range: 12–30°C.
Stat stop conditions. Extract/Room temperature, default setting is 18°C. Outdoor high temperature limit, default set-
ting is 23°C. Outdoor low temperature limit is 12°C. Start and stop time.
4.7.6.4.1Finding RPM for desired airflow
It is necessary to set fan RPM (revolutions per minute) for each airflow level to control airflow by changing fan speed.
Fan speed differ for each household because of different unit size, duct system and system pressure. In order to find
correct fan speed, external tool must be used at Systemair website.
1. Go to Systemair website and find your unit.
2. Go to Diagram tab and type in desired airflow values in l/s, m
3
/h, m
3
/s or cfm for supply and extract air. Input pres-
sure drop in duct system (if this value is not know, type in 100 Pa for both supply and extract air)
Fig. 4 Example of airflow and external pressure selection
3. See calculated speed values in revolutions per minute (rpm) for both supply and extract air in the table bellow
diagrams.
Fig. 5 Example speed for supply and extract air
4. Use this procedure to find fan speed for all airflow levels:
MINIMUM LEVEL
,
LOW LEVEL
,
NORMAL LEVEL
,
HIGH LEV-
EL
,
MAXIMUM LEVEL
.
5. Finally in the control panel go to
Service
menu, enter the password, then go to
Control Regulation
→
Fan
Control
. Choose
RPM
as airflow type and in sub-menu
Airflow Level Settings
enter calculated fan speed val-
ues for each level.
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