13
ENG
“optiMist” +0300065EN- rel. 1.1 - 29/01/2013
2.2 Type of supply water
optiMist can work with:
•
demineralised water
•
soft water
•
tap water
Following the evaporation process, the minerals dissolved in the
supply water will be partially transported by the air fl ow
as very fi ne powder and part of them will be deposited on the surfaces of
the separator and the fi ns of the heat exchanger.
The type and amount of minerals contained in the supply water
determine the frequency of regular maintenance operations needed to
remove these deposits from inside the AHU.
The main components of the system supplied by Carel which are aff ected
by any incrustations and which require regular periodic inspection and
maintenance are the nozzles and droplet separator.
In order to maintain system hygiene and to reduce system management
costs, Carel recommends supplying optiMist with water that has been
demineralised by reverse osmosis, as provided for in the principal norms
such as UNI 8884.
In particular, Norm UNI 8884 “Characteristics and treatment of water for
cooling and humidifi cation circuits” suggests that evaporative humidifi ers
be supplied with fresh water (as indicated in directive 98/83/EC) having
the following characteristics:
• electrical conductivity <100 S/cm;
• total hardness <5 °fH (50 ppm CaCO3);
• 6.5<pH< 8.5;
• chloride content <20 mg/l;
• silica content <5 mg/l;
Note 1:
If demineralised water is not available, softened water may be
used. In this case, in order to limit the aggressiveness of softened water, a
minimum hardness no less than 3°f should be ensured.
Note 2:
Carel recommends using mains water only if it has a hardness of
less than 16°f or a conductivity of less than 400μS/cm.
The use of mains water leads to ordinary maintenance operations (nozzle
and droplet separator cleaning) whose frequency depends on the
chemical composition of the water.
2.3 Water circuit installation: checklist
optiMist system name:
______________________________________
D
escription
N
otes
Cabinet level
Distance between cabinet-rack/water distribution system: ≤10 m.
Water supply connection
Water inlet pressure ≥2 bar (0.2 MPA, 29 PSI)
Filters fi lled with water
Drain connected to the water drain system
Supply water within the limit values. See section “Supply water
characteristics”
Calibration optional separator diff erential switch (if present)
Date: _______________
Signature: _______________________________________