Water Quality - Hitachi YUTAKI S80 Series Installation And Operation Manual

WATER PIPING
Tank connections
The domestic hot water connections of the tank are located where
it is visible in the following images:
Water connections
Space heating
Connection be- Connection be-
tween indoor unit tween indoor unit
and tank (heating and tank (heating
coil inlet connec- coil outlet connec-
tion) tion)
DHW inlet
connection
Heating coil inlet
connection
Piping size
(mm (inches))
Heating coil
From
indoor
unit
DHWS-(195/260) Ø19.05
S-2.0H1E (3/4")
20
DHW space
DHW inlet con-
DHW outlet connec-
nection (Cold tion (Hot water from
water to the tank) the tank)
Heating coil outlet
connection
DHW outlet con-
nection
DHW
To
From DHW
indoor
installation installation
unit
Ø19.05 Ø19.05
(3/4") (3/4")
PMML0291A rev.2 - 09/2014

5.1.3 Water quality


Heating coil and DHW circuit
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 treat-
ment with chemicals before application as treated water.
• It is mandatory to do not add any kind of antifreeze product to
the water circuit.
• To avoid deposits of scale on the heating coil surface it is man-
datory to ensure a high water quality with low levels of CaCO
• It is also necessary to analyse the quality of water by checking
pH, electrical conductivity, ammonia ion content, sulphur con-
tent, and others. Should the results of the analysis be not
good, the use of industrial water would be recommended for
the heating coil circuit.

Recommendations for the DHW circuit
The following is the recommended standard water quality.
Item
Electrical Conductivity (mS/m)
(25°C) {µS/cm} (25 °C)
Chlorine Ion (mg CI¯/I)
Sulphate (mg/l)
Combination of chloride and
sulphate (mg/l)
Total Hardness (mg CaCO
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 showed in "{}" are for reference only according
to the former unit.
To DHW
• (3): Water range will be according s/UNE 112076:2004 IN.
Ø19.05
(3/4")
DHW
Tendency
space
Water
supplied Corrosion
(3)
100~2000
(2)
max. 250
max. 250
max. 300
/I) 60~150
3
.
3
(1)
Deposits
of scales