Daikin UHA075B5, Catalogue/Engineering Data

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Water in the water system must be softened to prevent scale in the heat exchanger and affecting the heat
exchanger performance. Water not softened can also cause scale in the water pipes and cause the water
resistance to increase. This affects the water flow and the performance of the water pump. Softened water
must meet the following requirements.
Besides, water should be meet the standard of domestic water.
Water quality requirements
Item
Benchmark
value
Tendencies
Corrosion Scaling
Benchmark
items
pH (25°C) 7.5 ~ 9.0 ○ ○
Conductivity (25°C) μS/cm < 800 ○ ○
Cl
-
mg (Cl
-
)/L < 200 ○
SO
4
2-
mg (SO
4
2-
)/L < 200 ○
Acid consumption
mg (CaCO
3
)/L < 100
○
(pH = 4.8)
Total hardness mg (CaCO
3
)/L < 200 ○
Reference
items
Fe mg (Fe)/L < 1.0 ○ ○
S
2-
mg (S
2-
)/L 0 ○
NH
+
mg (NH
+
)/L < 1.0 ○
SiO
2
mg (SiO
2
)/L < 50 ○
Note: ○ represents factors that may cause corrosion or scaling.