10T8Y1B
VRV-W IV System Air Conditioner
4P399208-1 – 2015.01
Installation and operation manual
13
9.6.
System containing VRV DX indoor units
System setup
Example of connection in case of heat recovery system
Connection to BS unit
Piping between outdoor unit and BS unit: thick line (3 pipe)
Piping between BS unit and indoor unit: thin line (2 pipe)
Example 3: with multi outdoor unit layout
Maximum allowable length
Between outdoor and indoor units
Between outdoor branch and outdoor unit (only in case >10 HP)
Maximum allowable height difference
Branch with Refnet joint
Branch with Refnet joint and
Refnet header
Branch with Refnet header
Single outdoor unit
system
Example 1.1
Example 1.2
Example 1.3
Multi outdoor unit
system
Example 2.1
Example 2.2
Example 2.3
Indoor unit
Refnet joint
Refnet header
Multi outdoor unit
connection piping
kit
a
b
k
i
j
c
d
e
s
r
q
o
m
n
p
Unit
REFNET joint (A-G)
BS units
( B1 - B4 )
Indoor units
( 1 - 8 )
Heat recovery system
( 1 - 6 )
Cooling only
( 7 · 8 )
l
f
g
h
H2
H1
1
2
3
4
5
6
7
8
B2
B3
B4
B1
A
B
C
D
E
F
G
c
Unit
REFNET joint (A·B)
REFNET header
BS units ( B1 - B5 )
Indoor units
( 1 - 8 )
H1
1
2
3
4
5
6
7
8
B1
B2
B3
B4
B5
d
e
f
g
h
i
j
k
l
m
a
b
Heat recovery system
( 1 - 4 , 7 · 8 )
Cooling only
( 5 · 6 )
n
p
o
H2
A
B
REFNET header
a
b
f
h
j
d
c
e
g
i
k
l
m
n
o
Unit
1
2
3
4
5
6
7
8
B1
B2
B3
B4
B5
B6
BS units
( B1 - B6 )
Indoor units
( 1 - 8 )
Heat recovery system
( 1 - 6 )
Cooling only
( 7 · 8 )
H1
H2
Unit 1
REFNET joint (A-G)
BS units
( B1 - B4 )
Indoor units
( 1 - 8 )
Heat recovery
system ( 1 - 6 )
Cooling only
( 7 · 8 )
a
b
c
d
e
1
2
3 4
5
6
7
8
First outdoor
branch
s
r
p
q
n
o
k
i
l
j
h
g
f
H3
H1
H2
m
B1
B2
B3
B4
A
B
C
D
E
F
G
a
m
b
Unit 1
REFNET joint (A·B)
REFNET header
BS units
( B1 - B5 )
Heat recovery system
( 1 - 4 , 7 · 8 )
Indoor units
( 1 - 8 )
Cooling only
( 5 · 6 )
1
2
3
4
5
6
7
8
B1
B2
B3
B4
B5
c
d
e
f
g
h
i
j
k
l
n
p
o
u
t
s
r
H3
H2
H1
A
B
REFNET header
a
b
d
f
c
e
g
Unit 1
1
2
3
4
5
6
7
8
B6
B5
B4
B3
B2
B1
BS units
( B1 - B6 )
Heat recovery
system ( 1 - 6 )
Indoor units
( 1 - 8 )
Cooling only
( 7 · 8 )
h
i
j
k
l
m
n
o
H3
H1
H2
Refnet joint
Refnet joint
BS units
BS units
Indoor units
Indoor units
Heat recovery system
Heat recovery system
Cooling only
Cooling only
Refnet header
Refnet header
First outdoor branch
First outdoor branch
3-pipe
2-pipe
Outdoor
unit side
HP/LP gas
Indoor
unit side
Suction
gas
Gas piping
Liquid
Liquid
piping
BS unit
Actual piping length
120 m
Example 1.1
unit 8: a+b+c+d+e+s
≤
120 m
Example 2.1
unit 8: a+b+c+d+e+s
≤
120 m
Example 1.2
unit 4: a+b+i+j
≤
120 m
unit 5: a+b+k
≤
120 m
unit 8: a+m+n+p
≤
120 m
Example 1.3
unit 8: a+o
≤
120 m
unit 4: a+h+i
≤
120 m
Equivalent length
140 m
—
—
—
Total piping length
300 m
Example 1.1
a+b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q+r+s
≤
300 m
Example 2.1
a+b+c+d+e+f+g+h+i+j+k+l+m+n+o+p+q+r+s
≤
300 m
—
—
r
s
u
t
Actual piping length
10 m
Example 3
r, s, t
≤
10 m; u
≤
5 m
Equivalent length
13 m
—
H1
≤
50 m (40 m) (if outdoor is located below indoor units)
H2
≤
15 m
H3
≤
2 m
