18
3
Refrigerant piping design
3-3. Selection of refrigerant piping
No.
Piping parts
Name
Selection of pipe size
Remarks
(1)
Outdoor unit
1st branching
section
Main pipe
Size of main pipe
Same as connecting pipe
size of the outdoor unit.
(2)
Branching section
Branching section
Branching pipe
Pipe size between branching sections
Pipe size differs based on the
total capacity code value of
indoor units at the
downstream side. If the total
value exceeds the capacity
code of the outdoor unit,
apply the capacity code of the
outdoor unit.
(3)
Branching section
Indoor unit
Indoor unit
connecting pipe
Connecting pipe size of indoor unit
(4) Branching section
Y-shaped
branching joint
Selection of branching section (Y-shaped branching joint)
(5) Branching section
Branching
header
Selection of branching section (Branching header)
(5)
(2)
(4)
(1)
(3)
(3)
(3)
(3)
(2)
(4)
(3)
(3)
Outdoor unit
Liquid pipe
Gas pipe
Main pipe
1st branching
section
Branching
pipe
Branching
header
Indoor
unit
Indoor
unit
Branching
pipe
Y-shaped
branching joint
→
Outdoor unit capacity type
Gas pipe
Liquid pipe
0404 type
15.88
9.52
0504 type
15.88
9.52
0604 type
19.05
9.52
→
Total capacity codes of indoor units at down
stream side
Gas pipe
Liquid pipe
Equivalent to HP
Equivalent to capacity
Below 2.4
Below 6.6
12.70
9.52
2.4 to below 6.4
6.6 to below 18.0
15.88
9.52
6.4 or more
18.0 or more
19.05
9.52
→
Capacity rank
Gas pipe
Liquid pipe
005 to 012 type
9.52
6.35
014 to 018 type
12.70
6.35
020 to 056 type
15.88
9.52
Model name
Y-shape branch joint
RBM-BY55E
Model name
Branching header
For 4 branches
RBM-HY1043E
For 8 branches
RBM-HY1083E
