6-1 Selection of Piping Material
• Make sure that the inner side and outer side of the piping used is clean and free of contaminants, such as sulphur, oxide, dust, chips, oil and fat, and water.
It is desirable that the maximum oil adhesion in the piping is 30 mg per 10 m.
• Use the following type of refrigerant piping.
Material: Seamless phosphorus deoxidized copper tube (C1220T-O for a maximum outer diameter of 15.9 mm and C1220T-1/2H for a mini-
mum outer diameter of 19.1 mm)
Refrigerant piping size and wall thickness: Decide the size and thickness from the following table.
(This product uses R410A. The withstand pressure of O type may be insufficient if it is used for piping with a minimum diameter of
19.1 mm. Therefore, be sure to use 1/2 H type with a minimum thickness of 1.0 mm.
If O type is used for piping with a minimum diameter of 19.1 mm, a minimum thickness of 1.2 mm will be required. In that case, be
sure to perform the blazing of each joint.)
• Be sure to perform piping work within the range specified in the following table.
〈Refrigerant piping length〉
Max. permissible
LRMEQ5~20AY1
one-way piping length
(equivalent length)
LRLEQ5~20AY1
Max. branch piping length (actual length)
Max. difference in
unit below outdoor unit
height between indoor
and outdoor units
unit above outdoor unit
Difference in height between indoor units
〈Refrigerant piping size〉
(MT (Medium Temperature)) LRMEQ5~20AY1
Outdoor unit side
5A · 6A type
8A · 10A · 12A type
15A · 20A type
Piping between branching areas
(B, b, C, c)
Piping between branching areas and each unit Adjust the size of the piping so that it will coincide with the size of piping connecting to the indoor unit.
(LT (Low Temperature)) LRLEQ5~20AY1
Outdoor unit side
5A · 6A type
8A · 10A · 12A type
15A · 20A type
Piping between branching areas
(B, b, C, c)
Piping between branching areas and each unit Adjust the size of the piping so that it will coincide with the size of piping connecting to the indoor unit.
6
a + b + c + d ≤ 130m (d is d1 or d2 whichever is longer)
a + b + c + d ≤ 70m (d is d1 or d2 whichever is longer)
b + c + d ≤ 30m (d is d1 or d2 whichever is longer)
H ≤ 35m (Note)
H ≤ 10m
H1 ≤ 0.5m
Note: A trap is required at 5 m intervals from outdoor unit.
Piping size
Liquid pipe
50m or less
50~130m
φ9.5 × 0.8 (O type)
φ12.7 × 0.8 (O type)
φ9.5 × 0.8 (O type)
φ12.7 × 0.8 (O type)
φ12.7 × 0.8 (O type)
φ15.9 × 0.8 (O type)
Select the piping from the following table in accordance with the total capacity of indoor units
connected downstream.
Total capacity of indoor units after branching
Less than 6.0 kW
6.0 kW or over and less than 9.9 kW
9.9 kW or over and less than 14.5 kW
14.5 kW or over and less than 18.5 kW
18.5 kW or over and less than 25.0 kW
25.0 kW or over and less than 31.0 kW
31.0 kW or over
No size after branching can exceed the size of any upstream piping.
Piping size
Liquid pipe
50m or less
50~70m
φ9.5 × 0.8 (O type)
φ12.7 × 0.8 (O type)
φ9.5 × 0.8 (O type)
φ12.7 × 0.8 (O type)
φ12.7 × 0.8 (O type)
φ15.9 × 0.8 (O type)
Select the piping from the following table in accordance with the total capacity of indoor units
connected downstream.
Total capacity of indoor units after branching
Less than 2.3 kW
2.3 kW or over and less than 4.4 kW
4.4 kW or over and less than 6.4 kW
6.4 kW or over and less than 7.8 kW
7.8 kW or over and less than 10.8 kW
10.8 kW or over and less than 13.4 kW
13.4 kW or over
No size after branching can exceed the size of any upstream piping.
Outdoor unit
Liquid piping
A
B
H
F
E
Showcase
H1
e
f
a
b
Gas pipe
50m or less
50~130m
φ19.1 × 1.0 (1/2H type)
φ22.2 × 1.0 (1/2H type)
φ25.4 × 1.0 (1/2H type)
φ28.6 × 1.0 (1/2H type)
φ31.8 × 1.1 (1/2H type)
φ34.9 × 1.1 (1/2H type)
Gas pipe size
Liquid pipe size
φ12.7 × 0.8 (O type)
φ6.4 × 0.8 (O type)
φ15.9 × 1.0 (1/2H type)
φ19.1 × 1.0 (1/2H type)
φ9.5 × 0.8 (O type)
φ22.2 × 1.0 (1/2H type)
φ25.4 × 1.0 (1/2H type)
φ28.6 × 1.0 (1/2H type)
φ12.7 × 0.8 (O type)
φ31.8 × 1.1 (1/2H type)
Gas pipe
25m or less
25~70mm
φ19.1 × 1.0 (1/2H type)
φ22.2 × 1.0 (1/2H type)
φ25.4 × 1.0 (1/2H type)
φ28.6 × 1.0 (1/2H type)
φ31.8 × 1.1 (1/2H type)
φ34.9 × 1.1 (1/2H type)
Gas pipe size
Liquid pipe size
φ12.7 × 0.8 (O type)
φ6.4 × 0.8 (O type)
φ15.9 × 1.0 (1/2H type)
φ19.1 × 1.0 (1/2H type)
φ9.5 × 0.8 (O type)
φ22.2 × 1.0 (1/2H type)
φ25.4 × 1.0 (1/2H type)
φ28.6 × 1.0 (1/2H type)
φ12.7 × 0.8 (O type)
φ31.8 × 1.1 (1/2H type)
C
D2
D1
Unit
cooler
d1
c
d2
(Unit : mm)
(Unit : mm)
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