SYSVRF2 IM

16
Fig.5-3
N1
(140)
N4(140)
N9
(112)
N10
(140)
N12
(28)
N13
(140)
N16
(56)
N15
(140)
N3(71)
N7(28)
N6
(140)
N8(140)
N14
(56)
N17
(140)
A
B
I
J
N
K
O
C
F
H
E
L1
L2
L3
L5
L7
L8
L11
L12
L13
L15
L14
L16
L9
a
c
d
f
g
h
j
l
m
n
o
p
q
k
S
R
g1
g2
g3
G1
D
N
2
(140)
b
L4
N5
(112)
G
L6
e
N
11
(71)
i
L
L10
M
P
W3
(12)
W2
(22)
W1
(32)
CAUTION
The equivalent length of each branch join is 0.5m.
The indoor units should be as equal as possible for installing on
both sides of the U-shape branch joint.
If the outdoor unit is above and the level difference is greater
than 20m, it is recommended that an oil return bend with
dimensions as specified in Figure 5-2 is set every 10m in the gas
pipe of the main pipe.
If the outdoor unit is below and the level difference is more than
40m, the liquid pipe of the main pipe (L1) should be increased
one size.
The piping between the farthest indoor unit and first indoor
branch joint should not exceed 40m in length unless the following
conditions are met, in which case the permitted length is up to
90m.
1.
2.
3.
4.
5.
The piping length and level difference requirements that apply are
summarized in Table 5-1 and are fully described as follows (refer to
Figure 5-1):
Requirement 1: The total length of piping in one refrigerant system
should not exceed 1000m. When calculating the total length of
piping, the actual length of the indoor main pipes (the piping
between the first indoor branch joint and all other indoor branch
joints, L2 to L16) should be doubled.
Requirement 2: The piping between the farthest indoor unit (N11)
and the first outdoor branch joint (R) should not exceed 175m
(actual length) and 200m (equivalent length). (The equivalent
length of each branch joint is 0.5m.)
Requirement 3: The piping between the farthest indoor unit (N11)
and first indoor branch joint (A) should not exceed 40m in length
(Ʃ{L9 to L13} + k ≤ 40m) unless the following conditions are met
and the following measures are taken, in which case the permitted
length is up to 90m:
Conditions:
Each indoor auxiliary pipe (from each indoor unit to its nearest
branch joint) joint does not exceed 20 m in length (a to m each ≤
20m).
The difference in length between {the piping from first indoor
branch joint (A) to the farthest indoor unit (N11)} and {the piping
from the first indoor branch joint (A) to the nearest indoor unit
(N1)} does not exceed 40m. That is: (Ʃ{L9 to L13} +
k) - (Ʃ{L2
to L3} + a) ≤ 40m.
Measures:
Increase the diameter of the indoor main pipes (the piping
between the first indoor branch joint and all other indoor branch
joints, L2 to L16) as follows, except for indoor main pipes which
are already the same size as the main pipe (L1), for which no
diameter increases are required.
Requirement 4: The largest level difference between indoor unit
and outdoor unit should not exceed 90m (if the outdoor unit is
above) or 110m (if the outdoor unit is below). Additionally: (i) If the
outdoor unit is above and the level difference is greater than 20m, it
is recommended that an oil return bend with dimensions as
specified in Figure 5-2 is set every 10m in the gas pipe of the main
pipe; and (ii) if the outdoor unit is below and the level difference is
more than 40m, the liquid pipe of the main pipe (L1) should be
increased one size.
Requirement 5: The largest level difference between indoor units
should not exceed 30m.
1.
2.
3.
4
5
a)
b)
a)
φ9.5→φ12.7 φ12.7→φ15.9 φ15.9→φ19.1
φ19.1→φ22.2 φ22.2→φ25.4 φ25.4→φ28.6
φ28.6→φ31.8 φ31.8→φ38.1 φ38.1→φ41.3
φ41.3→φ44.5 φ44.5→φ54.0
5.2 Selecting piping diameters