Installation Manual
31
Refrigerant piping system
Refrigerant piping installation
◆
Y branch method
Longest piping length
**Equivalent piping length
A+B+C+D+e
≤
120m
A+B+C+D+e
≤
140m
Longest piping length after 1st branch
B+C+D+e
≤
30m
Difference in height(Outdoor Unit
↔
Indoor Unit)
H
≤
50m ( 40m : Outdoor Unit is lower than Indoor Units)
Difference in height (Indoor Unit
↔
Indoor Unit)
h
≤
15m
*L
l
H
h
1 Outdoor Unit(Half size)
L 120m
h 15m
H 50m
Example : 5 Indoor Units connected
: Outdoor Unit
: 1st branch (Y branch)
: Indoor Units
: Downward Indoor Unit
➲
Main pipe diameter (A)
➲
Total piping length = A+B+C+D+a+b+c+d+e
≤
220m
➲
Refrigerant pipe diameter from branch to branch (B,C,D)
Downward Indoor Unit total capacity
[kW(Btu/h)]
~8.3(28,300)
Ø9.52(3/8 inch)
Ø15.88(5/8 inch)
~17.8(60,700)
Ø12.7(1/2 inch) / 9.52(3/8 inch)
Ø19.05(3/4 inch)
~27.9(95,200)
Ø12.7(1/2 inch)
Ø25.4(1 inch)
~42.4(144,700)
Ø12.7(1/2 inch)
Ø28.58(1
1
/
8
inch)
~58.5(199,600)
Ø15.88(5/8 inch)
Ø31.8(1
1
/
4
inch)
~75.4(257,300)
Ø19.05(3/4 inch)
Ø38.1(1
1
/
2
inch)
75.5(257,600)~
Ø22.2(7/8 inch)
Ø44.5(1
3
/
4
inch)
Liquid pipe
(mm)
Gas pipe
(mm)
WARNING
Install the same main pipe diameter as those connected after the initial branch where the pipe diameter
connected after the initial branch.
Ex) Where connecting the Indoor Unit to 24HP (67.2kW) to the 120%.
Main pipe diameter of Outdoor Unit: Ø 38.1 (Gas pipe) Ø 19.05(Liquid pipe)
Main pipe diameter of Outdoor Unit: Ø 44.5 (Gas pipe) Ø 22.2 (Liquid pipe)
depending on 120% Indoor Unit combination
Since main pipe diameter of Outdoor Unit Ø 38.1 (Gas pipe) Ø 19.05(Liquid pipe),
Ø 38.1 (Gas pipe) Ø 19.05(Liquid pipe) is used as the main pipe.
*: Must be satisfied both conditions
**: Assume equivalent pipe length
of Y branch to be 0.5m, that of
header to be 1m, calculation
purpose.
Apply 5, 6HP model only
Liguid pipe
Ø9.52(3/8 inch)
Gas pipe
Ø19.05(3/4 inch)
-
Liguid pipe
Ø9.52(3/8 inch)
Gas pipe
Ø22.2(7/8 inch)
Liguid pipe
Ø12.7(1/2 inch)
Gas pipe
Ø28.58(1
1
/
8
inch)
PIPE
1 Outdoor Unit
(Half Size)
1 Outdoor Unit
(Full Size)
5HP
6HP
OVER
8HP