:
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
6
Piping Design
Case 1
A210229
Fig. 15 —Piping Design - Case 1
• Bends in piping cause pressure loss during transportation of the refrigerant, so fewer bends increase performance.
• The equivalent length of each bend is 1.64 feet.
• The equivalent length of each Y-Joint is 1.64 feet.
• Total “downstream indoor capacity” is the total capacity of all the indoor units connected downstream.
For example, Y-joint
⑤
is connected with IDU4 and IDU5 (40VMF009A--3 + 40VMM007A--3), which has a downstream indoor
capacity of 16k (Capacity index 9 + 7 = 16).
• The pipe length difference from the first branch to each indoor unit must not exceed 65 feet.
For example, the distance from IDU1 to the first branch is L3 + A, the distance from IDU6 to the first branch is L2, while the distance
from IDU5 to the first branch is L3 + L4 + L5 + L6 + E, so make sure that |L2 - (L3 + A)|, |L2 - (L3 + L4 + L5 + L6 + E)| and |(L3 + L4
+ L5 + L6 + E) - (L3 + A)| are all less than 65 feet.
Table 4 —Piping Length
*1 If only one IDU connects to the ODU, the total piping length must not exceed 328 feet.
Table 5 —Selection of “L1”
*When the length of L1 > 230 feet, the gas pipe should be increased from 5/8” to 3/4”, or from 3/4” to 7/8”. The pipe adapter must be
located as close as possible to the outdoor unit.
Table 6 —Selection of L2~L6, A, B, C, D, E
ITEM
PIPING in the FIGURES
MAXIMUM LENGTH
EQUIVALENT
Total piping length
L1 + L2 + L3 + L4 + L5 + L6 + A + B + C + D + E
492*1
-
Maximum distance from ODU to farthest IDU
L1 + L3 + L4 + L5 + L6 + E
296
328
First branch to farthest IDU
L3 + L4 + L5 + L6 + E
131
-
Height between ODU and IDU (ODU above IDU)
H
164
-
Height between ODU and IDU (ODU below IDU)
H’
131
-
Height between IDU and IDU
h1
49
-
Height between first branch to IDU
h2
49
-
Model
Gas Pipe
Liquid Pipe
38VMB036HDS3-1
5/8 *
3/8
38VMB048HDS3-1
38VMB060HDS3-1
3/4 *
Downstream Indoor Capacity (Kbtu/h)
Gas Pipe
Liquid Pipe
Capacity ≤ 15K
1/2
1/4
15K < Capacity ≤ 78K
5/8
3/8