Assembly Of Heat Wheel; Ahu Water Quality; Water Quality Requirements; Appendix - Daikin DM AHU Manual

9. Appendix

9.1 Assembly of heat wheel

1. Heat wheel unit bottom section has already assembled with heat wheel support assembly
and heat wheel baffle bottom when delivered.
2. Placed the baffle centre to the penta-post / centre-post or panel.
3. Placed the heat wheel on the heat wheel support assembly in the bottom section from
opening on top/side, depends on the design.
4. Screw the heat wheel to the heat wheel support assy. by using self-drilling screws.
5. screwed the heat wheel baffle left/right and centre
6. Assemble the top cabinet section to the bottom section. If required, remove some panel to
facilitate assembly work of heat wheel. Screw the baffle left/right and centre to top section
cabinet.
7. Assemble the heat wheel baffle top.
8. Assembled back the remaining panels.
9.2

AHU Water Quality

Water quality requirements: Water softening treatment must be given in advance to prevent
scaling in the heat exchanger which may affect heat exchange effect. Moreover, water
without softening treatment may form scale in the pipe to increase water resistance which
will affect water flow and pump work efficiency.
Benchmark pH (25°C)
items
Conductivity (25°C)
Chloride Ion Cl
Sulfate Ion SO
Acid Consumption (pH=4.8)
Total Harness
Reference Ferrum Fe
items
Sulphion S
Ammonium Ion NH
Silicon Oxide SiO
Note : O - factor related to the tendency of corrosion or scaling
9.3 AHU Commissioning Check Sheet
Table 6 – Water Quality Requirements
Item
- mg (Cl
2- mg(SO
4
mg(CaCO
mg(CaCO
mg(Fe) / L
2- mg(S
+ mg(NH
4
mg(SiO
2
- 18 -
Baseline
Value
- 7.5 ~ 9.0
µS / cm <800
- ) / L <200
2- ) / L <200
4
) / L <100
3
) / L <200
3
<1.0
2- ) / L 0
+ ) / L <1.0
4
) / L <50
2
Tendency
Corrosion Scaling
O O
O O
O
O
O
O
O O
O
O
O