Refrigerant pipe diameter from branch to branch (B,C,D)
Downward indoorunit total
capacity [kW(Btu/h)]
Liquid pipe
[mm(inch)]
Low Pressure Gas pipe
[mm(inch)]
High Pressure Gas pipe
[mm(inch)]
≤ 5.6(19,100) Ø6.35(1/4) Ø12.7(1/2) Ø9.52(3/8)
< 16.0 (54,600) Ø9.52(3/8) Ø15.88(5/8) Ø12.7(1/2)
< 22.4 (76,400) Ø9.52(3/8) Ø19.05(3/4) Ø15.88(5/8)
< 33.6(114,700) Ø9.52(3/8) Ø22.2(7/8) Ø19.05(3/4)
< 50.4(172,000) Ø12.7(1/2) Ø28.58(1-1/8) Ø22.2(7/8)
< 67.2(229,300) Ø15.88(5/8) Ø28.58(1-1/8) Ø22.2(7/8)
< 72.8(248,400) Ø15.88(5/8) Ø34.9(1-3/8) Ø28.58(1-1/8)
< 100.8(344,000) Ø19.05(3/4) Ø34.9(1-3/8) Ø28.58(1-1/8)
< 173.6(592,500) Ø19.05(3/4) Ø41.3(1-5/8) Ø34.9(1-3/8)
< 184.8(630,700) Ø22.2(7/8) Ø41.3(1-5/8) Ø34.9(1-3/8)
≤ 291.2(993,600) Ø22.2(7/8) Ø53.98(2-1/8) Ø41.3(1-5/8)
Guide for Conditional Application(**)
If the below conditions are satisfied, limit of longest pipe length after 1st branch( l) could be extended
by 40m(131ft) → 90m(295ft).
• Pipe diameter Size Up
Pipe diameter(only Liquid/low pressure gas pipes) between 1st branch and last branch(HR unit) is increased byone step.
If the pipe diameter of B, C3 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 increase
.
• Correction for calculating the total pipe length
When calculating total pipe length, pipe B,C,D length should be calculated twice.
: A + B x 2 + C3 x 2 + D x 2 + C1 + C2 + a + b + c + d + e + f + g + i + j + k + l + m + n ≤ Overall Pipe Length
• Indoor unit pipe length
Length of pipe from each indoor unit to the closest HR unit (a, b, c, d, e, f, g, i, j, k, l, m, n) ≤ 40m (131ft).
• Difference in length between outdoor unit and the farthest or closest indoor unit
[Length of pipe from outdoor unit to the farthest indoor unit 12 (B + C3 + D + k)] - [Length of pipe from outdoor unit to the
closest indoor unit 1 (C1 + a)] ≤ 40m (131ft)
• After 1st branch directly connected indoor unit(Heat Pump System Only)
When installing pipe of indoor unit directly connected after 1st branch more than 40m and less than 90m,
-Pipe diameter is increased by one step.
Ø 6.35 → Ø 9.52 → Ø 12.7 → Ø 15.88 → Ø 19.05 → Ø 22.2 → ...
-Pipe length should be calculated twice.
Cautions for Y branch pipe
• In case of pipe diameter connected after first branch(B) is bigger than the main pipe diameter(A), B should be of the same
size with A.
• Do not choose the main pipe diameter by downward indoor unit total capacity, but its outdoor/outside unit model name.
• Do not let the connection pipe from branch to branch exceed the main pipe diameter chosen by outdoor unit model name.
[Example 1] In case indoor unit combination ratio 120% is connected to 24HP(67.2 kW) outdoor unit.
- Outdoor unit main pipe diameter A : Ø34.9(Gas pipe), Ø15.88(liquid pipe)
- Pipe diameter B after first branch according to 120% indoor unit ombination(80.6kW): Ø34.9(gas pipe),Ø19.05(liquid pipe)
▷ Therefore, pipe diameter B connected after first branch would be Ø34.9(gas pipe) / Ø15.88(liquid pipe)
which is same with main pipe diameter.
[Example 2] Where connecting the indoor units to the 22HP (61.6kW) outdoor unit to 130% of its system capacity (80.1kW)
and branching 7k (2.2kW) indoor unit at the 1st branch.
- Main pipe diameter(22 HP outdoor unit): Ø28.58(gas pipe), Ø15.88(Liquid pipe)
- Pipe diameter between 1st and 2nd branch (77.9kW indoor units) :
Ø34.9(Gas pipe), Ø19.05(Liquid pipe) in conformity with downward indoor units.
▷ Since the main pipe diameter of 22HP outdoor unit is Ø28.58 (gas pipe), Ø15.88(Liquid pipe) is used
as the main pipe and the connection pipe between 1st and 2nd branch.
Cautions for header branch pipe
• It is recommended to install the difference between the length of the pipe after header branch(a~f) and the length of the
pipe connected to indoor unit to be the minimum.
• As the pipe length difference increases, there may be performance differences between indoor units.
Installation of Outdoor Unit
4. Refrigerant Piping System
Installation
10
To Next Page
Loading...
Need help?
General