Hitachi AIR CORE 700 PPIM-B18UFA1DQ Manuel D'utilisation, D'installation Et D'entretien page 21

CAUTION
!
If a lower sound level is further required, install silencer (field-supplied).
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Design duct arrangement as "Unit External Static Pressure=Pressure Drop of Duct+Pressure Drop of
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Air Outlet and Air Inlet". If duct design is not appropriate, big sound and splash will occur.
Before unit starting up, ensure the setting ESP is almost same with field duct pressure. If are not
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appropriate, big sound and splash will occur.
4.3.6 Air Return Modification
Air supply at side and return at rear:
If there is enough installation space adopt side air supply and rear return, to reduce the noise effectively.
Set the maintenance port as per requirement to carry out the maintenance smoothly.
NOTICE
This duct unit return air outside need to be connected 39.3 inch (1m) duct at least in field.
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It is recommended to adopt the installation way of side supply and rear return that has lower noise.
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Air inlet and outlet of the units need to be connected with air duct, and insulation treatment need
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to be applied to the flange connection of the inlet and outlet and air duct of inlet & outlet so as to
prevent condensation.
If air duct is not installed, perform insulation treatment to the sheet metal part of the outlet.
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Use aluminum tape to seal the side air duct of inlet and outlet and connection part of the units, so
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a s to prevent air leakage.
Air filter must be installed inside the side duct of air inlet. (Select filter with dust collection
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efficiency (weighing method) of more than 50%).
Heat insulation material must be used to prevent condensation on the air duct. (Material: fiberglass
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or EPE, with thickness of more than 0.98 inch (25mm)).
Air resistance pressure reduction for the unit type air duct should be not more than the maximum
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ESP that can be selected.
Distance from the air outlet to the ground should be appropriate, and air flow from the outlet
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should not blow toward personnel for long term.
To reduce the vibration and noise and the condensation caused by the inappropriate connection
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method of the air outlet, it is suggested to adopt flexible connection for the air supply and return
duct and the units, and perform sealing and insulation work to air outlet and flexible connection.
Air outlet flange needs to be tightly sealed and well insulated.
It is suggested to use plastic material (PVC, ABS) or wooden outlet grill so as to prevent air outlet
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grill from being condensed. If metal air outlet grill is used, condensation may occur.
Duct
Air supply
Figure 4.9 Side Supply and Rear Return
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4. Indoor Unit Installation
Return air