Mitsubishi Heavy Industries FDC112KXEN6 Technical Manual page 217

(iii) Duct work
1 Supply air duct
¡ 1-spot, 2-spot, 3-spot and 4-spot with 200 type duct are the standard specifications. Determine the number of spots
based on following table.
Notes (1) Shield the central supply air port for 2-spot.
Notes (2) Shield the supply air port around the center for 3-spot.
¡ Limit the difference in length between spots at less than 2:1.
¡ Reduce the length of duct as much as possible.
¡ Reduce the number of bends as much as possible. (Corner R should be as larger as possible.)
¡ Use a band, etc. to connect the indoor unit and the supply air duct flange.
¡ Conduct the duct installation work before finshing the ceiling.
2 Access door
Access door must be provided without fail.
¡ Dimensions of access door and service space
(See exterior dimensions in page 51 to 54.)
3 Return air port
¡ When shipped, the return air port lies on the back.
¡ When connecting the duct to the return air port, remove the air filte if it is fitted to return air port.
¡ When placing the return air port to carry out suction from the bottom side, use the following procedure to replace the
return air duct joint and the bottom plate.
• Remove the screws which fasten
the bottom plate and the duct joint
on the return air port of the unit.
¡ Make sure to insulate the duct to prevent dewing on it.
4 Install the specitic supply air duct in a location where the air will circulate to the entire room.
¡ The duct connection is specific to the 200 circular duct.
¡ Conduct the installation of the specific supply air hole and the connection of
the duct before attaching them to the ceiling.
¡ Insulate the area where the duct is secured by a band for dew condensation
prevention.
FDUM22 FDUM28, 36, 45, 56
1-spot -spot
Bad example
• Replace the removed bottom plate
and duct joint.
213
- -
FDUM71, 90
~ 3-spot
(1)
Bad example Good example
• Fit the duct joint with a screw,
fit the bottom plate.
Secure with a band,etc.
FDUM112, 140
3 ~ 4-spot
( )
Supply air
duct