Kaisai KOU-12HFN1-QRC8, Service Manual

Page: 103 / 170

Drainage pipe installation
Installation 99
6. Drainage pipe installation
Install the drainage pipe as shown below and take measures against condensation. Improperly installation
could lead to leakage and eventually wet furniture and belongings.
6.1 Installation principle

Ensure at least 1/100 slope of the drainage pipe

Adopt suitable pipe diameter

Adopt nearby condensate water discharge
6.2 Key points of drainage water pipe installation
6.2.1 Considering the pipeline route and elevation

Before installing condensate water pipeline, determine its route and elevation to avoid intersection with
other pipelines and ensure slope is straight.
6.2.2 Drainage pipe selection

The drainage pipe diameter shall not small than the drain hose of indoor unit

According to the water flowrate and drainage pipe slope to choose the suitable pipe, the water flowrate
is decided by the capacity of indoor unit.
Relationship between water flowrate and capacity of indoor unit
Capacity (x1000Btu) Water flowrate (l/h)
12 2.4
18 4
24 6
30 7
36 8
42 10
48 12
60 14
According to the above table to calculate the total water flowrate for the confluence pipe selection.
For horizontal drainage pipe (The following table is for reference)
PVC pipe
Reference value of inner
diameter of pipe (mm)
Allowable maximum water flowrate (l/h)
Remark
Slope 1/50 Slope 1/100
PVC25 20 39 27
For branch pipe
PVC32 25 70 50
PVC40 31 125 88
Could be used for confluence pipe PVC50 40 247 175
PVC63 51 473 334
Attention: Adopt PVC40 or bigger pipe to be the main pipe.
For Vertical drainage pipe (The following table is for reference)
PVC pipe
Reference value of inner
diameter of pipe (mm)
Allowable maximum water flowrate (l/h) Remark
PVC25 20 220
For branch pipe
PVC32 25 410
PVC40 31 730
Could be used for confluence pipe
PVC50 40 1440
PVC63 51 2760
PVC75 67 5710
PVC90 77 8280
Attention: Adopt PVC40 or bigger pipe to be the main pipe.