Hitachi YUTAKI S Series Technical Catalogue page 113

8 Refrigerant and water piping
Space heating and DHW
8.3.7 Water quality
!
C A U T I O N
• Water quality must be according to EU council directive 98/83 EC.
• Water should be subjected to filtration or to a softening treatment with chemicals before application as treated water.
• It is also necessary to analyse the quality of water by checking pH, electrical conductivity, ammonia ion content, sulphur content, and
others. Should the results of the analysis be not good, the use of industrial water would be recommended.
• No antifreeze agent shall be added to the water circuit.
• To avoid deposits of scale on the heat exchangers surface it is mandatory to ensure a high water quality with low levels of CaCO
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Recommendations for the DHW circuit
The following is the recommended standard water quality.
Item
Electrical Conductivity (mS/m) (25°C)
{µS/cm} (25 °C)
(2)
Chlorine Ion (mg CI¯/I)
Sulphate (mg/l)
Combination of chloride and sulphate (mg/l)
Total Hardness (mg CaCO /I)
3
?
N O T E
• (1): The mark " " in the table means the factor concerned with the tendency of corrosion or deposits of scales.
• (2): The value shown in "{}" are for reference only according to the former unit.
• (3): Water range will be according s/UNE 112076:2004 IN.
105 TCGB0123 rev.2 - 10/2019
DHW space
Water supplied Corrosion
(3)
100~2000
max. 250
max. 250
max. 300
60~150
.
3
Tendency
(1)
Deposits of scales
8