102
Drain Piping
(a) Drain piping should always be in a downhill grade (1/50-1/100) and avoid riding across an elevation or making 
traps.
(b) When connecting the drain pipe to unit pay suffcient attention not 
to apply excess force to the piping on the unit side. Also x the piping 
at a point as close as possible to the unit.
(c) For unit without water pump please refer to the digram and select 
drain pipe size according to drain opening inner diameter size. 
The drain pipe shall be slant downwards (greater than 1/100). The 
horizontal length of the drain pipe shall be less than 20m. In case of 
long pipe supports shall be provided every 1.5-2m to prevent wavy 
form.Central piping shall be laid out according to the right gure. Take 
care not to apply external force onto the drain pipe connection part.
(d) For unit with water pump drain pipeuse hard PVC general purpose 
pipe VP which can be purchased locally. When connecting insert 
a PVC pipe end securely into the drain socket before tightening 
securely using the attached drain hose and clamp. Adhesive must not 
be used for connection of the drain socket and drain hose (accessory).
(e) When constructing drain piping for several units  position the 
common pipe about 100 mm below the drain outlet of each unit 
as shown in the sketch. Use VP-30(11/4") or thicker pipe for this 
purpose.
(f) The hard PVC pipe put indoor side should be heat insulated. Do 
not ever provide an air vent.
(g) The height of the drain head can be elevated up to a point 500 
mm above the ceiling and when an obstacle exists in the ceiling 
space elevate the piping to avoid the obstacle using an elbow or 
corresponding gadget. When doing this if the stretch for the needed 
height is higher than 500 mm the back-ow quantity of drain at the 
event of interruption of the operation gets too much and it may cause 
overow at the drain pan. Therefore make the height of the drain pipe 
within the distance given in the sketch below.
(h) Avoid positioning the drain piping outlet at a place where 
generation of odor may be stimulated. Do not lead the drain piping 
direct into a sewer from where sulfur gas may generate.
Unit model The size of drain opening
AD90S2SM3FA AD90S2SM4FA
AD105S2SM3FA AD105S2SM4FA
AD125S2SM3FA AD125S2SM4FA
AD140S2SM3FA AD140S2SM4FA
 Φ25mm