Daikin UWL040B5 - Water System Installation Procedures

21
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 ow and the performance of the water pump. Softened water must meet the following
requirements.
Note:
○
represents factors that may cause corrosion or scaling.
Connecting Water Pipes
■ No water pump is provided as an accessory. A proper water pump must be installed to overcome resistance of the
water pipes.
■ Water pressure gauges and thermometers must be installed at the water inlets and outlets to facilitate the reading of
unit operation status.
■ The heat exchanger at the water side is made of stainless steel. Water scale may accumulate depending on the water
quality and must be cleared using chemicals from time to time. Therefore, a chemical cleaning pipe connector needs
to be installed at the water pipes (see the following gure).
■ The water ow must be in the rated range. If the water ow is too small, scale may accumulate and degrade the
performance of the unit, cause the antifreeze device to activate, or cause rust points and refrigerant leakage. If the
water ow is too large, the unit may be corroded due to water impact.
■ A adiabatic water tank with a proper volume is suggested to installed. If the capacity is too small, the unit might
frequently restart, which causes wear and tear on the compressor.
■ An expansion water tank must be installed at the return water side of the water system to adapt to water pressure
variations in the water supply system caused by ambient temperature changes.
■ An auto relief valve must be installed at the highest point in the water system. A suitable water discharge valve must
be installed at the lowest point in the water system.
■ The water pipes must be adiabatic to avoid heat loss and condensate water.
■ Please follow the "Illustration for water system installation" and drawings from the design institute while installing the
water system.
■ Install the Y-shaped water lter inside the water inlet pipe and rinse the lter screen after commissioning.
■ Before injecting water, make sure that no sand, rubble, rust, soldering tin residue or other impurities exist in the pipe,
as these things might damage the heat exchanger.
■ While rinsing the water system, please bypass the unit and the terminal heat exchanger using by-pass valves.
Water quality requirements
Water System Installation Schematic Diagram
Water system installation
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
mg (SO
4
)/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 mg (S )/L 0 ○
NH
+
mg (NH
+
)/L < 1.0 ○
SiO
2
mg (SiO
2
)/L < 50 ○
-
-
2-
2- 2-
2-