18
WARNING
!
• It is recommended that difference of piping length for pipes
connected to the Indoor Unit is minimized. Performance
difference between Indoor Units may occur.
• When the any one (or both ) of below conditions are satisfied,
the diameter of main pipe (A) must be increased according to
below table.
- The equivalent length between outdoor unit and the farthest
indoor unit is 90 m or more. (Liquid and Gas pipes are
increased.)
Refrigerant pipe diameter from outdoor unit to first branch. (A)
Outdoor unit
Liquid pipe [mm(inch)]
total capacity(HP)
6
Ø 9.52(3/8)
5
Ø 9.52(3/8)
4 / 3
Ø 9.52(3/8)
Refrigerant pipe diameter from branch to branch (B,C)
Downward Indoor
Unit total capacity
Liquid pipe [mm(inch)]
[kW(Btu/h)]
≤ 5.6(19 100)
Ø 6.35(1/4)
< 16.0(54 600)
Ø 9.52(3/8)
≤ 22.4(76 400)
Ø 9.52(3/8)
Outdoor unit Connection
WARNING
!
• In case of pipe diameter B connected after first branch is bigger
than the main pipe diameter A, B should be of the same size
with A.
Ex) In case indoor unit combination ratio 120 % is connected to
24 HP(67.2 kW) outdoor unit.
1) Outdoor unit main pipe diameter A : Ø 34.9(Gas pipe),
Ø 15.88(liquid pipe)
2) Pipe diameter B after first branch according to 120 %
indoor unit ombination(80.6kW) : Ø 34.9(gas pipe),
Ø 19.05(liquid pipe)
Therefore, pipe diameter B connected after first branch
would be Ø 34.9(gas pipe) / Ø 15.88(liquid pipe) which is
same with main pipe diameter.
[Example]
Do not choose the main pipe diameter by downward indoor unit
total capacity but its outdoor unit model name.
Do not let the connection pipe from branch to branch exceed the
main pipe diameter chosen by outdoor unit model name.
EX) Where connecting the indoor units to the 22 HP (61.6 kW)
outdoor unit to 130 % of its system capacity (80.1 kW) and
branching 7k (2.2 kW) indoor unit at the 1st branch.
1) Main pipe diameter(22 HP outdoor unit): Ø 28.58(gas pipe),
Ø 15.88(Liquid pipe)
2) Pipe diameter between 1st and 2nd branch (77.9 kW indoor
units) :
Ø 34.9(Gas pipe), Ø 19.05(Liquid pipe) in conformity with
downward indoor units.
Since the main pipe diameter of 22 HP outdoor unit is
Ø 28.58(gas pipe), Ø 15.88(Liquid pipe) is used as the main
pipe and the connection pipe between 1st and 2nd branch.
Indoor Unit Connection
Indoor Unit connecting pipe from branch (a,b,c,d,e,f)
Indoor Unit capacity
≤ 5.6(19 100)
< 16.0(54 600)
!
• Bending radius should be
at least twice the diameter
of the pipe.
• Bend pipe after 500 mm or
Gas pipe [mm(inch)]
more from branch(or
header).
Ø 19.05(3/4)
Do not bend U type.
Ø 15.88(5/8)
It may cause Performance
unsatisfactory or noise.
Ø 15.88(5/8)
• If want U type, bending R
is more than 200 mm.
Gas pipe [mm(inch)]
The amount of Refrigerant
Ø 12.7(1/2)
The calculation of the additional charge should take into account the
length of pipe and CF(correction Factor) value of indoor unit.
Ø 15.88(5/8)
Ø 19.05(3/4)
Additional charge(kg)
Amount refrigerant of Indoor units
Example) 4 Way Ceiling Cassette 14.5 kW -1 ea, Ceiling concealed
Attach the additional refrigerant table of IDU.
!
Use only 2-series of indoor unit. Ex) ARNU***2
The amount of Refrigerant (for R32)
The calculation of the additional charge should take into account the
length of pipe and CF(correction Factor) value of indoor unit.
Additional charge(kg)
Amount refrigerant of Indoor units
Example) 4 Way Ceiling Cassette 14.5 kW -1 ea, Ceiling concealed
Liquid pipe
[kW(Btu/h)]
[mm(inch)]
Ø 6.35(1/4)
Ø 9.52(3/8)
CAUTION
500 mm or more
=
Total liquid pipe : Ø 9.52 mm
+
Total liquid pipe : Ø 6.35 mm
+
CF value of indoor unit
Duct 7.3 kW-2 ea, Wall Mounted 2.3 kW-4 ea
CF = 0.64 × 1 + 0.26 × 2 + 0.24 × 4 = 2.12 kg
CAUTION
=
Total liquid pipe : Ø 9.52 mm
+
Total liquid pipe : Ø 6.35 mm
+
CF value of indoor unit
Duct 7.3 kW-2 ea, Wall Mounted 2.3 kW-4 ea
CF : 0.41 x 1 + 0.3 x 2 + 0.2 x 4 = 1.81 kg
Gas pipe [mm(inch)]
Ø 12.7(1/2)
Ø 15.88(5/8)
500 mm or more
x 0.053(kg/m)
x 0.022(kg/m)
x 0.035(kg/m)
x 0.019(kg/m)