Eco Air CTBU-09HWFN1-M(C), Service Manual, Page: 96 / 219

93
intersection with other pipelines and ensure
slope is straight.
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
PVC50 40 1440
for confluence
pipe
PVC63 51 2760
PVC75 67 5710
PVC90 77 8280
Attention: Adopt PVC40 or bigger pipe to be the
main pipe.
3. Individual design of drainage pipe
system

The drainage pipe of air conditioner shall
be installed separately with other sewage
pipe, rainwater pipe and drainage pipe in
building.

The drainage pipe of the indoor unit with
water pump should be apart from the one
without water pump.
4. Supporter gap of drainage pipe

In general, the supporter gap of the
drainage pipe horizontal pipe and vertical
pipe is respectively 1m~1.5m (3.28~4.92ft)
and 1.5m~2.0m(4.95~6.56ft).

Each vertical pipe shall be equipped with
not less than two hangers.

Overlarge hanger gap for horizontal pipe
shall create bending, thus leading to air
block.
T o o lo n g d is ta n c e
G a s b a g
5. The horizontal pipe layout should avoid
converse flow or bad flow
D r a in a g e p ip e
W a t e r f lo w
D r a in a g e p ip e
D r a in a g e p ip e
D r a in te e
D r a in te e
W a te r flo w
W a te r flo w
W a te r flo w
W a te r flo w
W a te r flo w
W a te r flo w
W a te r flo w W a te r flo w
D r a in te e
B r a n c h p ip e
W a t e r f lo w
W a t e r f lo w
K e e p a c e r t a in d e g r e e
B r a n c h p ip e
G a s G a s
M a in p ip e
M a in p ip e

The correct installation will not cause
converse water flow and the slope of the
branch pipes can be adjusted freely