Cassette Type Air Conditioner Unit
22
T-joint converging drain pipes
≥1
00
mm
(3
-7
/8i
nch
)
T-joint converging drain pipes
0~
280
mm
(0~
11
in
ch
)
Fig. 4.21
(4).
When the drain hose cannot keep a sufficient gradient, it is necessary to fit a riser
pipe (field supplied) to it.
(5).
If the air flow of indoor unit is high, this might cause negative pressure and result
in return suction of outdoor air. Therefore, U-type water trap shall be designed on
the drainage side of each indoor unit.(Fig. 4.22)
(6).
Install one water trap for each unit.
(7).
Installation of water trap shall consider easy cleaning in the future.
Indoor unit
Joint
Indoor unit
Indoor unit
H
H/2
Joint
Fig. 4.22 Fig. 4.23 Fig. 4.24
(8).
Connection of drainage branch pipe to the standpipe or horizontal pipe of drainage
main pipe
The horizontal pipe cannot be connected to the vertical pipe at a same height. It
can be connected in a manner as shown below:
NO.1: Attach the 3-way connection of the drainage pipe joint as shown in Fig. 4.25.
NO.2: Attach the drain elbow as shown in Fig. 4.26.
NO.3: Attach the horizontal pipe as shown in Fig. 4.27.
