20
ENGLISH
Pattern 8
A
A
• * : Maximum indoor units per a branch are 8 indoor units
HR1
48 k 48 k
1 2
HR2
*
B
12 k 12 k 12 k 12 k
3 4 5 6
24 k
7
24 k
8
• Pipe installation from outdoor units to HR units
  : 3 pipes(Low pressure Gas pipe, High pressure Gas pipe, Liquid pipe)
• Pipe installation from HR units to indoor units
  : 2 pipes(Gas pipe, Liquid pipe)
B
A
1
HR1
Outdoor
Unit
Indoor Unit Y Branch pipe
Low pressure Gas pipe
High pressure Gas pipe
Liquid pipe
Gas pipe
Liquid pipe
Head Branch pipe
Indoor
Unit
Keep the 40 m distance from the first branch to the farthest indoor.
5 m (16 ft)
15 m (49 ft)
1) under 40 m (131 ft)
Keep the sum of indoor capacity under 56.4 kW (192 kBtu/h).
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
Indoor
Unit
1) under 40 m (131 ft)
Y branch
Keep the sum of indoor capacity under 56.4 kW (192 kBtu/h).
Y branch method
Combination of Y
branch/header method
Header method
Ⓐ : Outdoor Unit
Ⓑ : 1st branch (Y branch)  
Ⓒ : Indoor Units
Ⓓ : Downward  Indoor Unit
Ⓐ : Outdoor Unit
Ⓑ : 1st branch (Y branch)  
Ⓒ : Y branch
Ⓓ : Indoor Unit
Ⓔ : Header
Ⓕ : Sealed piping
Ⓐ : Outdoor Unit
Ⓒ : Indoor Units
Ⓓ : Sealed piping
Ⓔ : Header
l 150 m(492 ft) (200 m(656 ft) : Conditional application)*
h 40 m(131 ft)
H 50m(164ft)
L150 m(492 ft) (200 m(656 ft) : Conditional application)*
Indoor 
Unit
l 150 m(492 ft) (200 m(656 ft) : Conditional application)*
h 40 m(13 1ft)
H 50m(164ft)
L150 m(492 ft) (200 m(656 ft) : Conditional application)*
l 40m(131ft) 
h 40m(131ft) 
H 50m(164ft)
L 150 m(492 ft)
Refrigerant piping system
1 Outdoor Unit
h * : See the Table 4
h * : See the Table 4
For Heat Pump System Installation
Piping length from outdoor branch to outdoor unit ≤ 10 m(33 ft),
equivalent length : max 13 m(43 ft) (for 14 Ton or more)
Additional Application
To satisfy below condition to make 40 m(131 ft) ~ 90 m(295 ft) of
pipe length after first branch.
• Diameter of pipes between first branch and the last branch
should be increased by one step, except pipe diameter B, C, D
is same as Diameter A
Ø 1/4(6.35 mm) ’ Ø 3/8(9.52 mm) ’ Ø 1/2(12.7 mm) ’
Ø 5/8(15.88 mm) ’ Ø 3/4(19.05 mm) ’ Ø 7/8(22.2 mm) ’
Ø 1(25.4)*, Ø 1-1/8(28.58 mm) ’ Ø 1-1/4(31.8 mm)*,
Ø 1-3/8(34.9 mm) ’ Ø 1-1/2(38.1 mm)* ’ Ø 1-5/8(41.3 mm)
* : It is not necessary to size up.
h If the step up size is not available, you can not select the next
higher size available.
• While calculating whole refrigerant pipe length, pipe B, C, D
length should be calculated twice.
A+Bx2+Cx2+Dx2+a+b+c+d+e ≤ 500 m(1 641 ft)
• Length of pipe from each indoor unit to the closest branch
(a,b,c,d,e) ≤ 40 m(131 ft)
• [Length of pipe from outdoor unit to the farthest indoor unit 5
(A+B+C+D+e)] 
- [Length of pipe from outdoor unit to the closest indoor unit 1
(A+a)] ≤ 40 m(131 ft)