Level Difference
(Outdoor unit ↔ Outdoor unit)
5 m [16.4 ft]
Max length from first branch to
each outdoor unit (L1, L2, L3)
Less than 10 m [32.8 ft]
(equivalent length of piping 13 m
[42.7 ft])
h * : See Table 4
WARNING
Increased Pipe Diameter(table 2)
- When pipe length is 90m [295 ft] or more from ODU to 1st
branch
- When level difference is 50 m [164 ft] or more
!
WARNING
• Branch pipe can not be used after header.
• It is recommended that difference in length of the pipes con-
nected to the indoor units (a~f) is minimized. Performance dif-
ference between indoor units may occur.
!
Y branch
Method
Combination of Y
branch/header
Method
Header
Method
Max pipe
length
Outdoor Unit
↔
Indoor Unit
Longest
pipe
length(L)
A+B+C+D+e ≤ 150 m
[492 ft]
(200 m [656 ft] : Condi-
tional application)*
A+B+b ≤ 150 m [492 ft]
A+C+e ≤ 150 m [492 ft]
(200 m [656 ft] : Condi-
tional application)*
A+f ≤ 200 m
[656 ft]
Equivalent
pipe length
175 m [574 ft]
(225 m [738 ft] : Condi-
tional application)*
175 m [574 ft]
(225 m [738 ft] : Condi-
tional application)*
225 m
[738 ft]
Total pipe
length
1000 m [3281 ft] 1000 m [3281 ft]
1000 m
[3281 ft]
Max
difference
in height
Outdoor Unit
↔ Indoor Unit
Difference in
height(H)
110 m [361 ft] 110 m [361 ft] 110 m [361 ft]
Indoor Unit
↔ Indoor Unit
Difference in
height(h)
40 m [131 ft] 40 m [131 ft] 40 m [131 ft]
Longest pipe
length after
1st branch
Pipe
length(ℓ)
40 m [131 ft]
(90 m [295 ft] : Condi-
tional application)*
40 m [131 ft]
(90 m [295 ft] : Condi-
tional application)*
40 m [131 ft]
(Table 1) Limit Pipe length
(Table 2) Refrigerant pipe diameter from outdoor unit to first branch. (A)
ODU
capacity
(hp)
Pipe diameter when pipe
length is < 90m (295ft)
(Standard)
Pipe diameter when pipe
length is ≥ 90m (295ft)
Pipe diameter when height differ-
ential (ODU↔IDU) is > 50m (164ft)
Liquid Pipe
mm (inch)
Gas Pipe
mm (inch)
Liquid Pipe
mm (inch)
Gas Pipe
mm (inch)
Liquid Pipe
mm (inch)
Gas Pipe
mm (inch)
8
Ø9.52 (3/8) Ø19.05 (3/4) Ø12.7 (1/2) Ø22.2 (7/8) Ø12.7 (1/2) Not increased
10
Ø9.52 (3/8) Ø22.2 (7/8) Ø12.7 (1/2) Ø28.58 (1-1/8) Ø12.7 (1/2) Not increased
12~16
Ø12.7 (1/2) Ø28.58 (1-1/8) Ø15.88 (5/8) Ø34.9 (1-3/8) Ø15.88 (5/8) Not increased
18~22
Ø15.88 (5/8) Ø28.58 (1-1/8) Ø19.05 (3/4) Ø34.9 (1-3/8) Ø19.05 (3/4) Not increased
24
Ø15.88 (5/8) Ø34.9 (1-3/8) Ø19.05 (3/4) Ø41.3 (1-5/8) Ø19.05 (3/4) Not increased
26~34
Ø19.05 (3/4) Ø34.9 (1-3/8) Ø22.2 (7/8) Ø41.3 (1-5/8) Ø22.2 (7/8) Not increased
36~60
Ø19.05 (3/4) Ø41.3 (1-5/8) Ø22.2 (7/8) Ø44.5 (1-3/4) Ø22.2 (7/8) Not increased
62~64
Ø22.2 (7/8) Ø44.5 (1-3/4) Ø25.4 (1) Ø53.98 (2-1/8) Ø25.4 (1) Not increased
66~96
Ø22.2 (7/8) Ø53.98 (2-1/8) Ø25.4 (1) Ø53.98 (2-1/8) Ø25.4 (1) Not increased
(Table 3) Refrigerant pipe diameter from first branch to last branch (B,C,D)
Downward indoor unit
total capacity [kW(Btu/h)]
Liquid pipe
[mm(inch)]
Gas pipe
[mm(inch)]
≤ 5.6(19,100)
Ø6.35(1/4) Ø12.7(1/2)
< 16.0 (54,600) Ø9.52(3/8) Ø15.88(5/8)
≤ 22.4 (76,400)
Ø9.52(3/8) Ø19.05(3/4)
< 33.6 (114,700) Ø9.52(3/8) Ø22.2(7/8)
< 50.4 (172,000) Ø12.7(1/2) Ø28.58(1-1/8)
< 67.2 (229,400) Ø15.88(5/8) Ø28.58(1-1/8)
< 72.8(248,500) Ø15.88(5/8) Ø34.9(1-3/8)
< 100.8(344,000) Ø19.05(3/4) Ø34.9(1-3/8)
< 173.6(592,500) Ø19.05(3/4) Ø41.3(1-5/8)
< 184.8(630,700) Ø22.2(7/8) Ø44.5(1-3/4)
≤ 224.0(764,400)
Ø22.2(7/8) Ø53.98(2-1/8)
(Table 4) Conditional Application
Condition Example
1
Diameter of pipes be-
tween first branch and the
last branch should be in-
creased by one step, ex-
cept pipe diameter B,C,D
is same as Diameter A
40 m [131 ft] <
B+C+D+e
90 m [295 ft]
’
B, C, D
Change a diameter
2
While calculating whole re-
frigerant pipe length, pipe
B,C,D length should be cal-
culated twice.
A+Bx2+Cx2+Dx2
+a+b+c+d+e
≤
1 000 m [3 281 ft]
3
Length of pipe from each
indoor unit to the closest
branch
a,b,c,d,e
≤
40 m
[131 ft]
4
Length of pipe from out-
door unit to the farthest
indoor unit 5
(A+B+C+D+e)] - [Length
of pipe outdoor unit to the
closest indoor unit 1
(A+a)]
≤
40 m [131 ft]
(A+B+C+D+e)-
(A+a) ≤ 40 m
[131 ft]
• To satisfy below condition to make 40 m ~ 90 m of pipe length after first branch.
Ø6.35(1/4) ’ Ø9.52(3/8), Ø9.52(3/8) ’
Ø12.7(1/2), Ø12.7(1/2) ’ Ø15.88(5/8),
Ø15.88(5/8) ’ Ø19.05(3/4), Ø19.05(3/4) ’
Ø22.2(7/8), Ø22.2(7/8) ’ Ø25.4(1),
Ø25.4(1) ’ Ø28.58(1-1/8), Ø28.58(1-1/8) ’
Ø31.8(1-1/4), Ø31.8(1-1/4) ’ Ø34.9(1-3/8),
Ø34.9(1-3/8) ’ Ø38.1(1-1/2)
1,MFL67221438,영영 2018. 10. 4. 영영 11:29 Page 14