Dimensions of the Air Supply Outlet and Return Air Inlet
21
A
B
D
C
Air Supply Outlet Return Air Inlet
Models
Air Supply Outlet
Return Air Inlet
A
B
C
D
4MXD8509A
6.1
(156)
26.1
(662)
22.8
(580)
6.4
(162)
4MXD8512A
4MXD8518A
6.1
(156)
33.9
(862)
30.7
(780)
6.4
(162)
4MXD8521A
6.1
(156)
41.8
(1062)
38.6
(980)
6.4
(162)
4MXD8524A
Unit: Inch (mm)
Installation of the Return Air Connection
Return Air Cover Plate
Downward Return Air
Backward Return Air
Rectangular Flange
12
Ceiling Concealed Unit
1.
The default installation location of the rectangular flange is in the back and the return air cover
plate is in the bottom.
2.
If downward return air is desired, exchange the location of the rectangular flange and the
return air cover plate.
3. Connect one end of the return air duct to the return air outlet of the unit by rivets and the other
to the return air louver. For convenience you may adjust the height with a section of flexible
connection material.
4. More noise is likely to be produced in the downward return air mode than the backward return
air mode. It is suggested to install sound insulation and a plenum box to minimize the noise.
5. The installation method can be chosen when considering the installation location available in
the building and maintenance access, etc.
