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SPACE HEATING AND DHW
●
DHW tank supplies hot water from tap water. Domestic hot
water is only used when tap water is connected.
●
For safety, do not add ethylene glycol into water circulation. If
added, water will be contaminated when heat exchanger coil
leaks.
●
When water hardness is more than 250-300 ppm, recommend
using softened water to reduce DHW tank scale.
●
Immediately flush DHW tank with fresh water after installation.
Flush once every day in first five days of installation.
●
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
DHW tank's design pressure, a pressure reducer must be
fitted.
●
After used for a while (depend on local water quality and use
frequency), clean DHW tank and remove scales.
a.
Power off and close water inlet valve.
b.
Open water outlet valve and drainage valve to empty
DHW tank.
When scales are removed, temperature in DHW tank
may be a little high, it should prevent burns or drainage
equipment damaged.
c.
Close drainage valve after cleaning several minutes with
water inlet valve opened. Ensure effluent water is closed
after DHW tank is full of water. Power on and get back to
work.
●
Always check DHW tank and its surroundings has accumulated
water or not. If leak, contact local dealer.
8.5 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.
Item
Standard Quality pH
(25 °C)
Electrical Conductivity
(mS/m) (25 °C)
Less than 400
{µS/cm} (25 °C)
(2)
Chlorine Ion
-
(mg CI
/L)
Sulphur Acid Ion
-
(mg H
SO
/L)
4
The amount of Acid
consumption (pH 4.8)
(mg CaCO
/L)
3
Total Hardness
(mg CaCO
/L)
3
Calcium Hardness
(mg CaCO
/L)
3
Silica L (mg SIO
/L)
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)
-
Sulphur Ion (mg S
2
/L)
Ammonium Ion (mg
Less than 1.0 Less than 0.1
+
NH
/L)
4
Remaining Chlorine
Less than 0.3 Less than 0.3
(mg CI/L)
Floating Carbonic Acid
Less than 4.0 Less than 4.0
(mg CO
/L)
2
Index of Stability
Item
Electrical Conductivity
(mS/m) (25°C)
(2)
{μS/cm} (25 °C)
-
Chlorine Ion (mg CI
/L)
Sulphate (mg/L)
Combination of chloride
and sulphate (mg/L)
Total Hardness (mg
CaCO3 /L)
●
(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.
●
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
anode(optional accessory) can be installed.
22
Chilled water system
Circulating
water (20°C
Supply water
less than)
6.8 ~ 8.0
6.8 ~ 8.0
Less than 30
Less than 40
Less than
300
Less than 50 Less than 50
Less than 50 Less than 50
Less than 50 Less than 50
Less than 70 Less than 70
Less than 50 Less than 50
Less than 30 Less than 30
It shall not be detected
6.8 ~ 8.0
-
DHW
Tendency
space
Water
Corrosion
supplied
100~2000
●
Max 250
●
Max 250
●
Max 300
●
60~150
Tendency (1)
Depos-
Corro-
its of
sion
scales
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
(1)
Deposits
of scales
●
●
●
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