SPACE HEATING/COOLING AND DHW
9.4 WATER CONTROL
It is necessary to analyze the quality of water by checking
pH, electrical conductivity, ammonia ion content, sulphur
content, and others. The following is the recommended
standard water quality.
Chilled water system
Circulating
Item
water (20°C
less than)
Standard Quality pH
6.8 ~ 8.0
(25 °C)
Electrical Conductivity
Less than 40
(mS/m) (25 °C)
Less than 400
(2)
{µS/cm} (25 °C)
Chlorine Ion
Less than 50
(mg CI¯/L)
Sulphur Acid Ion
Less than 50
(mg H
SO¯/L)
4
The amount of Acid
consumption (pH
Less than 50
4.8) (mg CaCO
/L)
3
Total Hardness
Less than 70
(mg CaCO
/L)
3
Calcium Hardness
Less than 50
(mg CaCO
/L)
3
Silica L (mg SIO
/L)
Less than 30
2
Reference Quality
Less than 1.0 Less than 0.3
Total Iron (mg Fe/L)
Total Copper
Less than 1.0 Less than 0.1
(mg Cu/L)
2¯
Sulphur Ion (mg S
/L) It shall not be detected
Ammonium Ion
Less than 1.0 Less than 0.1
+
(mg NH
/L)
4
Remaining
Less than 0.3 Less than 0.3
Chlorine (mg CI/L)
Floating Carbonic
Less than 4.0 Less than 4.0
Acid (mg CO
/L)
2
Index of Stability
6.8 ~ 8.0
Item
Electrical Conductivity
(mS/m) (25°C)
100~2000
(2)
{μS/cm} (25 °C)
Chlorine Ion (mg CI¯/L)
Sulphate (mg/L)
Combination of chloride
and sulphate (mg/L)
Total Hardness
(mg CaCO
/L)
3
●
(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.
Tendency (1)
Depos-
Corro-
Supply water
sion
scales
6.8 ~ 8.0
●
Less than 30
Less than
●
300
Less than 50
●
Less than 50
●
Less than 50
Less than 70
Less than 50
Less than 30
●
●
●
●
●
●
-
●
DHW
Tendency
(1)
space
Water
Deposits
Corrosion
supplied
of scales
●
●
Max 250
●
Max 250
●
Max 300
●
●
60~150
●
●
Water should be subjected to filtration or to a softening
treatment with chemicals before application as treated water.
●
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
CaCO3.
●
To prevent the storage tank from corrosion, the electronic
its of
anode(optional accessory) can be installed.
●
9.5 DHW TANK SELECTION
●
●
DHW tank for heat pump type heating system shall be
selected according to the requirements in this instruction and
on-site use requirements.
●
If the selection, installation and wiring are not carried out
according to the requirements in this instruction, we would not
●
be responsible for the problems caused by the DHW tank.
●
Hot water may cause serious burns. Test water temperature
with hands. Use after the water is mixed till proper temperature.
●
●
Connecting of water pipe with tap water pipe should be
operated by qualified staff using proper piping material
●
according to local regulations and standards.
●
●
When the high domestic hot water temperature can be
a potential risk for human injuries, a mixing valve (field
●
supplied) shall be installed at the hot water outlet connection
of the DHW tank. This mixing valve shall secure that the
hot water temperature at the hot water tap never rise above
a set maximum value. This maximum allowable hot water
temperature shall be selected according to the applicable
legislation.
DHW tank selection (Storage capacity)
When selecting a tank for DHW operation, take into
consideration the following points:
●
- The volume of the tank has to meet with the daily
consumption in order to avoid stagnation of water.
- Fresh water must circulate inside the DHW tank water
circuit at least one time per day during the first days
after the installation has been performed. Additionally,
flush the system with fresh water when there is no
consumption of DHW during long periods of time.
- Try to avoid long runs of water piping between the tank
and the DHW installation in order to decrease possible
temperature losses.
- lf the domestic cold water entry pressure is higher than
the equipment's design pressure, an adequate pressure
reducer must be installed to ensure that the maximum
pressure is NOT exceeded.
22