2 Unit installation
Optional accessories
SMGB0099 rev.0 - 12/2016
85
2
The outdoor air inlet duct resistance increases as indicated in the following figure when using the T-duct connection. Use
it as a guide for fan selection.
0
2
4
6
50
100
150
200
0
Pass resistance of fresh air intake portion
Air flow volume (m
3
/min.)
Pass resistance (Pa)
6 HP
Limit of fresh
air intake
amount
?
N O T E
This chart shows the relationship between the air flow volume and the
pass resistance when the T-tube connecting kit is used with the fresh
air intake kit.
2.13.3.2 Branch pipe (PDF-71C, PDF-160CI)
If there are obstacles such as partitions inside the room that prevent the air from circulating correctly, branches can be
installed to provide an even air temperature.
Suitable return air grilles must be installed in line with the volume of return air. If air conditioning is provided in an
adjoining room, always install a return grille.
Partition
Small room return grille
Flexible duct (max. length: 5m)
Example of a branch pipe.
Branch duct flange
Example of branched duct
Branch pipe installation
The connections for the branch pipe are indicated in the following figure.
There are six knock-out holes. Cut the insulation material on the outer surface in a circle and line up the notches at the
four corners. Use a screwdriver or similar and remove.
