10
4 Water connections
3.7 Laying the condensate hose
It is advisable to lay the condensate hose as near to the ver-
tical as possible and to feed the condensate either directly
into an open funnel or below the siphon.
If the steam-distribution pipe is fitted above the humidifier, the
condensate can be fed back to the unit by placing the end of the
hose in the filling cup. In this case a small siphon should be for-
med with the condensate hose.
If the condensate is drained off directly, it is advisable to feed
back the condensate hose separately. The end of the condensate
hose should be in the open air, if the end of the hose is submer-
ged in water, the condensate is prevented from draining away
freely.
4.1 Water quality
NORDMANN humidifiers use ordinary tap water for the production of pure steam. The electrical conductivity should
be between 125 and max. 1250 microSiemens per cm.
The hardness of water is measured in accordance with the international unit millimol calcium and magnesium ions
per litre (mmol/l), previously in degrees of German hardness (DH).
Soft water:
up to 1.3 mmol/l up to 7 ° DH
Fairly hard water:
1.3 bis 2.5 mmol/l 7-14 ° DH
Hard water:
2.5 bis 3.8 mmol/l 14-21 ° DH
Very hard water:
over 3.8 mmol/l over 21 ° DH
Other international units:
1° DH = 1.79° French hardness
1° DH = 1.25° English hardness
1° DH = 1.05° US hardness
1° DH = 10 mg/l CaO
1° DH = 17.9 mg/l CaCO
3
(ppm)
NORDMANN's electrode steam humidifiers function with water ranging from soft to very hard, without the need for
prior treatment.
However, for fairly hard water and above, we recommend the use of the SC System (NORDMANN’s patented self
cleaning system), which greatly reduces the amount of maintenance required for the cylinder. The SC System is
available as option built-in ex works or as a retrofit option.
Fig. 3.29
Condensate
fed back to
the unit
Condensate
drained off
separately
