7. Refrigerant Piping System
17
Multi V S Outdoor Unit
Installation of Outdoor Units
■ Refrigerant pipe diameter from outdoor unit to first branch. (A)
• * : If available on site, select pipe size from the pipe diameter table according to capacity. Otherwise it doesn’t
need to be increased.
• Model line up could be different in accordance with target region.
■ Refrigerant pipe diameter from branch to branch (B,C,D)
■ Conditional Application (only for Y Branch method)
If the below conditions are satisfied, limit of longest pipe length after 1st branch(ℓ) could be extended by
40m → 90m.
1. Pipe diameter Size Up
Pipe diameter(Liquid/Gas pipes) between 1st branch ↔ last branch(B,C,D) is increased by on step.
If the pipe diameter of B,C,D is same as A, it is not necessary.
: Ø 6.35 → Ø 9.52 → Ø 12.7 → Ø 15.88 → Ø 19.05 → Ø 22.2 → ...
If available on site, select pipe size from the pipe diameter table according to capacity.Otherwise it doesn’t need
to be increased.
2. Correction for calculating the total pipe length
When calculating total pipe length, pipe B,C,D length should be calculated twice.
: A+Bx2+Cx2+Dx2+a+b+c+d+e ≤ 300 m
3. Indoor unit pipe length
Length of pipe from each indoor unit to the closest branch (a,b,c,d,e) ≤ 40 m.
4. Difference in length between outdoor unit and the farthest or closest indoor unit
[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
Upward
Outdoor unit
total capacity
Standard Pipe Diameter
Increased Pipe Diameter
When equivalent pipe length is 90m or more from ODU to farthest IDU
HP
Liquid pipe
[mm(inch)]
Gas pipe
[mm(inch)]
Liquid pipe
[mm(inch)]
Gas pipe
[mm(inch)]
3, 4 Ø 9.52(3/8) Ø 15.88(5/8) Ø 12.7(1/2) Ø 19.05(3/4)
5 Ø 9.52(3/8) Ø 15.88(5/8) Ø 12.7(1/2) Ø 19.05(3/4)
6 Ø 9.52(3/8) Ø 19.05(3/4) Ø 12.7(1/2) Ø 22.2(7/8)
8 Ø 9.52(3/8) Ø 19.05(3/4) Ø 12.7(1/2) Ø 22.2(7/8)
10 Ø 9.52(3/8) Ø 22.2(7/8) Ø 12.7(1/2) Ø 25.4(1) *
12, 14 Ø 12.7(1/2) Ø 28.58(1-1/8) Ø 15.88(5/8) not increased
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(229,300) Ø15.88(5/8) Ø28.58(1-1/8 )