14 Piping installation
Installation and operation manual
20
RK RKXYQ8T7Y1B
VRV IV compressor unit for indoor installation
4P499900-1B – 2021.12
Indoor unit capacity
index
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
63~140
15.9
9.5
200
19.1
250
22.2
14.1.4
To select refrigerant branch kits
"14.1.3 To select the piping size"
19].
Refnet joint at first branch (counting from the compressor unit)
When using refnet joints at the first branch counted from the
compressor unit side, choose from the following table in accordance
with the capacity of the compressor unit.
Example:
Refnet joint c
(B→C/D).
Compressor unit capacity type
Refrigerant branch kit
5 HP
KHRQ22M20TA
8 HP
KHRQ22M29T9
Refnet joints at other branches
For refnet joints other than the first branch, select the proper branch
kit model based on the total capacity index of all indoor units
connected after the refrigerant branch.
Example:
Refnet joint c
(C→D/D).
Indoor unit capacity index
Refrigerant branch kit
<200
KHRQ22M20TA
200≤x<260
KHRQ22M29T9
Refnet headers
Concerning refnet headers, choose from the following table in
accordance with the total capacity of all the indoor units connected
below the refnet header.
Indoor unit capacity index
Refrigerant branch kit
<260
KHRQ22M29H
INFORMATION
Maximum 8 branches can be connected to a header.
14.1.5
Refrigerant piping length and height
difference
The piping lengths and height differences must comply with the
following requirements.
H1
H2
H3
H5
L1
a
L2
L3
L4
L5
L6
L7
H4
b
EKEXV
AHU
VRV DX
VRV DX
c
c
a
Heat exchanger unit
b
Compressor unit
c
Refrigerant branch kit
VRV DX
VRV DX indoor unit
EKEXV
Expansion valve kit
AHU
Air handling unit
H1~H5
Height differences
L1~L7
Piping lengths
Minimum and maximum piping lengths
1
Heat exchanger unit →
Compressor unit
L1≤30 m
2
Actual piping length (equivalent
piping length)
(a)
L2+L3+L4≤70 m (90 m)
L2+L5+L6≤70 m (90 m)
L2+L5+L7≤70 m (90 m)
3
Total piping length (x=L1+L2+L3+L4+L5+L6+L7)
Minimum
10 m≤x
Maximum in case of
8 HP
x≤300 m
Maximum in case of
5 HP
If
Then
L1≤30 m
x≤115 m
L1≤25 m
x≤120 m
L1≤20 m
x≤125 m
L1≤15 m
x≤130 m
L1≤10 m
x≤135 m
L1≤5 m
x≤140 m
4
EKEXV →
AHU
L4≤5 m
5
First branch kit → Indoor unit/
AHU
L3+L4≤40 m
L5+L6≤40 m
L5+L7≤40 m
Maximum height differences
(b)
1
Heat exchanger unit ↔
Compressor unit
H1≤10 m
2
Compressor unit ↔ Indoor unit H2≤30 m
H3≤30 m
3
EKEXV ↔
AHU
H4≤5 m
4
Indoor unit ↔ Indoor unit
H5≤15 m
(a)
Assume equivalent piping length of refnet joint=0.5 m and
refnet header=1 m (for calculation purposes of equivalent
piping length, not for refrigerant charge calculations).
(b)
Either unit can be the highest unit.
14.2
Connecting the refrigerant piping
DANGER: RISK OF BURNING/SCALDING
14.2.1
Using the stop valve and service port
To handle the stop valve
Take the following guidelines into account:
▪ Make sure to keep all stop valves open during operation.
▪ The gas and liquid stop valves are factory closed.
▪ Do NOT apply excessive force to the stop valve. Doing so may
break the valve body.
To handle the service port
▪ Always use a charge hose equipped with a valve depressor pin,
since the service port is a Schrader type valve.
▪ After handling the service port, make sure to tighten the service
port cover securely. For the tightening torque, refer to the table
below.
▪ Check for refrigerant leaks after tightening the service port cover.
