Refrigerant piping system
Installation Manual
27
ENGLISH
Refrigerant piping system
Y branch method
Ú
Refrigerant pipe diameter from
branch to branch (B,C,D)
Ú
Total pipe length =
A+B+C+D+a+b+c+d+e ≤ 300m(984ft)
Ú
Outside unit
Ⓐ
~ 1st branch
Ⓑ
:
Main pipe diameter (A)
L Below 150m(492ft)
Below H 50m(164ft)
l
Below 40m(131ft)
Below 15m(49ft)
Indoor unit
direction
1. When installing 1 outside unit
independently
Ex) 5 indoor units connected
Ⓐ
: Outside unit
Ⓑ
: 1st branch (Y branch)
Ⓒ
: Indoor units
Ⓓ
: Indoor unit
For the first branch pipe (B), use the branch pipe
that fits the main pipe diameter (A).
Outside unit
Liquid pipe
Gas pipe
capacity
[mm(inch)]
[mm(inch)]
8 HP
Ø9.52(3/8)
Ø22.2(7/8)
10 HP
Ø9.52(3/8)
Ø22.2(7/8)
16 HP
Ø12.7(1/2)
Ø28.58(1-1/8)
20 HP
Ø12.7(1/2)
Ø28.58(1-1/8)
Total capacity of indoor units connected
to after branching [kW(Btu/h]
≤ 5.6(19,100)
Ø6.35(1/4)
Ø12.7(1/2)
<16(54,600)
Ø9.52(3/8)
Ø15.88(5/8)
≤ 22.4(76,400)
Ø9.52(3/8)
Ø19.05(3/4)
< 33(112,600)
Ø9.52(3/8)
Ø22.2(7/8)
< 47(160,400)
Ø12.7(1/2)
Ø28.58(1-1/8)
< 71(242,300)
Ø15.88(5/8) Ø28.58(1-1/8)
< 104(354,900)
Ø19.05(3/4)
Ø34.9(1-3/8)
104(354,900) ≤
Ø19.05(3/4)
Ø41.3(1-5/8)
Liquid pipe
[mm(inch)]
Gas pipe
[mm(inch)]
Longest pipe length (Equivalent pipe length)
A + B + C + D + e
≤
150m(492ft)( 175m(574ft))
Longest pipe length after 1st branching
B + C + D + e
≤
40m(131ft)
High/Low difference (Outside unit
÷
Indoor unit)
H
≤
50m(164ft)
High/Low difference (Indoor unit
÷
Indoor unit)
h
≤
15m(49ft)
L
ℓ
H
h
• When the pipe diameter (B) connected after 1st branching is larger than the main pipe diameter (A), Install the pipe with the pipe
diameter (B) after 1st branching that is the same as the main pipe diameter (A).
Ex) When connecting with 120% of the indoor unit to 10 HP
1) Outside unit main pipe diameter: Ø22.2(7/8) (Gas pipe) / Ø9.52(3/8)(Liquid pipe)
2) Pipe diameter after 1st branching by 120% indoor unit combination : Ø28.58(1-1/8) (Gas pipe) / Ø12.7(1/2) (Liquid pipe)
Therefore set the pipe diameter (B) after 1st branching to Ø22.2(7/8) (Gas pipe) / Ø9.52(3/8) (Liquid pipe) of main pipe diameter (A).
• When the pipe distance corresponding to the farthest indoor unit from the outside unit is 90m(295ft) or above, you must change the
main pipe diameter according to the outside unit capacity in accordance with the following table. (This applies to both the liquid and
gas pipes.)
Gas Pipe
Liquid Pipe
8, 10 HP .........................................................................Ø22.2(7/8)
’
Ø25.4(1)
8, 10 HP.........................................................................Ø9.52(3/8)
’
Ø12.7(1/2)
16, 20 HP .......................................................................Ø28.58(1-1/8)
’
Ø31.8(1-1/4)
16, 20 HP.......................................................................Ø12.7(1/2)
’
Ø15.88(5/8)