Branch Discharge Duct For 4-Way Cassette Type Indoor Units - Hitachi FSG1 Series Technical Catalogue

5. Attach an air filter on the air suction side of the duct for
fresh air intake at a position where servicing may be
carried out easily. (Air passing through the duct does not
pass through the filter of the main unit.)
6. Insulate the duct and the duct connection portion. In
addition, use only non-combustible materials for the duct
and insulation.
Duct (To be made of only
non-combustible materials)
Thermal Insulation
(Non-combustible materials)
Damper
Inspection Panel
Duct Fan
(Duct Fan Attachment Drawing)
?
NOTE:
All parts of the above figure be field-supplied.
7. The duct resistance of the fresh air intake portion will be
as shown in the figure below.
Use this as a guideline for selecting the duct fan.
8. In the case that a duct fan larger than the limit of fresh air
intake amount shown in the above figure is selected,
always use a damper and adjust the quantity of air.
9. Make an inspection panel for the servicing of the air filter
and damper below the duct fan.
Duct Resistance of Fresh Air Intake Portion
Static
Pressure
(mmAq)
RCI-1-0
RCI-2.0
RCI-2.5
RCI-3.0
Limit of Fresh
Air Intake
Amount
Air Filter
Fresh Air Intake Hood
with Gallery (Attached Drip-
Proof Hood Type)
RCI-4.0
RCI-5.0
Limit of
Fresh Air
Intake
Amount
Air Quantity (m³/min)
UNITS INSTALLATION
12.10.3 BRANCH DISCHARGE DUCT FOR 4-WAY
CASSETTE TYPE INDOOR UNITS.
In the cases shown in the figure below, branched ducts may
be employed to give uniform temperature air conditioning. In
the case that there are obstacles such as partitions inside
the room, and there are places where the air from the air
conditioner will not circulate well. A return air grille shall be
made as required, depending on the amount of return air. In
the case that an adjoining room is also air conditioned.
Always provide a return grille.
(Example of Branched Duct)
n
Fitting of Branched Duct
1. The branched duct connections are shown in the Fig. A.
There are Knockout holes. After cutting the insulation
material of the outside surface in a circular shape by
aligning the notches of the four corners, use a
screwdriver or the similar and remove it.
As for the connection duct, a flexible duct with a diameter
of Ø150 is standard, and the connection flange used in
this case shall be prepared at the site by referring to the
dimensions shown in Fig. B. After attaching the
connection flange to the indoor unit Knockout hole
portion, it must be thermally insulated by insulation
material the dimensions of which are shown in Fig. C.
12
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Flexible Duct
(Max. Length: 5m)
Small
Partition
Room
Return
Grille