Evaporator De-Icing; Fan Control - Dantherm DanX 1 XD User Manual

4. CONTROLS
IMPORTANT
If the compressor does not start, even if the temperature in the pool hall is below the set
point there can be the following reasons:
•
The unit runs in night mode (Closed Pool High / Closed Pool Low or STOP)
•
The outdoor / exhaust air damper setting (Minimum_Fresh_Air) is <10%.
Temperature level in the swimming pool hall is higher than the set point:
•
The compressor will be stopped. If the compressor runs, the humidity control, or a
build in water cooled condenser has taken over.
•
The heating coil will be stopped.
•
The outdoor / exhaust air dampers will open more to get more cooled outdoor air to
the pool hall (overriding the set point Fresh air amount - Minimum_Fresh_Air).
Secondly the by-pass damper will slowly open to avoided heating the outdoor air in
the heat exchanger.
•
The controller will give a digital signal to an optional cooling unit.

4.8.3 Evaporator de-icing

If the evaporator sensor (B26) is measuring a temperature <+2°C for more than 20 minutes
the compressor will be stopped and the outdoor / exhaust air dampers closed. At the same
time the fan speed goes up to full speed. When the evaporator has been de-iced, all
functions are going back to normal.

4.8.4 Fan control

Normally the fans are running at the speed set in the Time Program, but if the speed is set to
low speed (Open Pool Low or Closed Pool Low) there can be the following reasons, why the
unit is running still on full speed.
•
If the calculated dehumidification demand is >50%, which means there is a larger
difference between the actual humidity and the set point, the fans will go to full speed,
until the calculated dehumidification is again <50%.
•
If
Room_Temperature) the fans will go over to full speed until the set point temperature
has been reached again.
•
If there is a larger difference between the actual hall temperature and the set point
than 2°C the fans will go to high speed, until the difference is lower than 2°C.
•
If the supply air temperature is above the set point (Max_Supply_Temperature).
•
If the evaporator is been de-iced. The de-icing stops when the evaporator temperature
(Evaporator_Temperature) is >+2°C.
there is a demand for free cooling
32
(Outdoor_Air_Temperature <