Specifications

Control Specification SiBE04-624
70 Function and Control
3.10 Dew Prevention
Outline Cooling the air around us means that the air is dehumidified (condensation of water on the coil).
But because the air is cooled down, less water can be absorbed by the air and as a
consequence the relative humidity of the air rises. When the relative humidity of the outlet air
nears 100%, you will have water being blown in. To prevent this from happening, the unit will,
under certain circumstances, change its target evaporating temperature and the frequency of
the compressor. Normally speaking, even under these conditions (dew prevention safety
active), the room should still be cooled down, only slower. Of course, if the indoor unit is rather
on the small size in comparison to the heat load, this will not be the case and capacity shortage
complaints will follow.
Detail 1. Conditions for initiating the dew prevention function.
c
Operation mode is in cooling/dry.
d
Compressor is running.
z
When the temperature of indoor heat exchanger is lower than the target temperature of heat
exchanger, the compressor frequency will be pulled down by 2 Hz in every minute.
z
The target temperature of heat exchanger is calculated by the following formula with using
the room temperature and indoor humidity.
Target temp. of heat exchanger = 0.94 x room temp. + 0.27 x indoor humidity – 32.5
2. Conditions for ending the dew prevention function
c
Operation mode is not in cooling/dry.
d
Compressor is not running.