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EN/06.2016/i01 © STULZ S.p.A. – all rights reserved
WPA ExPlOrEr OrIGINAl INSTrUCTIONS
5.2 Chilled water quality
INFOrMATION
The following limits for the water circuit must not be exceeded
DANGEr
For outlet water temperatures lower or equal to +5°C and environments with temperatures
lower than 0°C, use non freezing mixture approved by STULZ
Feature
Minimum
value
Maximum
value
pH
(*)
7,0
8,0
Total hardness
(*)
°F
13
35
Conductivity
(*)
µS/cm
200
350
Alcalinity (HCO3)
(*)
mg/L
200
300
(*)
Considering water at tempe20°C
DANGEr
The chiller must not be used in conditions outside the limits specified in the nameplate
5.2.1 Glycol correction factors
INFOrMATION
In the case of addition of glycol in the fluid to be cooled, the technical data contained in this
paragraph shall be adjusted according to the coefficients shown in the following table.
Percentage of ethylene glycol
Percentage of propylene glycol
10%
20%
30%
40%
10%
20%
30%
40%
Freezing temperature
[°C]
-3.9
-8.9
-15.6
-23.4
-3.3
-7.8
-12.2
-20.6
Cooling capacity
Correction
factors on
the technical
data sheets
0.997
0.990
0.984
0.977
0.993
0.985
0.974
0.962
Power consumption
0.999
0.997
0.996
0.994
0.999
0.996
0.993
0.989
Flow of fluid to be cooled
1.014
1.033
1.068
1.117
0.989
1.009
1.017
1.040
Pressure drop on the fluid to be cooled side
1.07
1.16
1.30
1.48
1.04
1.14
1.23
1.37
5.3 Pressure Drops
With the following graphs you will find the pressure drops for different versions of the chiller.
