32
PIPE CONNECTIONS BETWEEN INDOOR AND OUTDOOR UNIT
ENGLISH
No.
Piping parts
Name
Selection of pipe size
③
Branching section
↓
Indoor unit
Indoor unit
connecting pipe
Connecting pipe size of indoor unit
Indoor unit
capacity[kW(Btu/h)]
Liquid pipe
[mm(inch)]
Gas pipe
[mm(inch)]
≤
5.6(19 100)
Ø 6.35(1/4)
Ø 12.7(1/2)
< 16.0(54 600)
Ø 9.52(3/8) Ø 15.88(5/8)
≤
22.4(76 400)
Ø 9.52(3/8) Ø 19.05(3/4)
≤
28.0(95 900)
Ø 9.52(3/8)
Ø 22.2(7/8)
Y branch method
Example : 5 Indoor Units connected
Ⓐ
: Outdoor Unit
Ⓑ
: 1st branch (Y branch)
Ⓒ
: Indoor Units
L 150 m
H 50 m
15 m
l
40 m
Refrigerant piping system
Total pipe length = A+B+C+D+a+b+c+d+e
≤
300 m
L
Longest pipe length
Equivalent pipe length(*)
A+B+C+D+e
≤
150 m
A+B+C+D+e
≤
175 m
l
Longest pipe length after 1st branch
B+C+D+e
≤
40 m
H
Difference in height (Outdoor Unit
÷
Indoor Unit)
H
≤
50 m (40 m : Outdoor Unit is lower than Indoor Units)
h
Difference in height (Indoor Unit
÷
Indoor Unit)
h
≤
15 m
• * : Assume equivalent pipe length of Y branch to be 0.5 m, that of header to be 1 m,
calculation purpose.