5 Preparation
Installer and user reference guide
15
RWEYQ8~1 RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452191-1 – 2017.04
Size up
HP class
Liquid piping outer diameter size (mm)
18~22
15.9 → 19.1
24
26~34
19.1 → 22.2
36~42
F: Piping between refrigerant branch kit and BP
unit
Heat pump mode in case of single outdoor unit
Pipe size for direct connection on BP unit must be based on the total
capacity of the connected indoor units (only in case RA DX indoor
units are connected).
Total capacity index
of connected indoor
units
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
20~62
12.7
6.4
63~149
15.9
9.5
150~208
19.1
Example:
Downstream capacity for F=[capacity index of unit 4]+[capacity index
of unit 5]
G: Piping between BP unit and RA DX indoor unit
Heat pump mode in case of single outdoor unit
Only in case RA DX indoor units are connected.
Indoor unit capacity
index
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
20, 25, 30
9.5
6.4
50
12.7
60
9.5
71
15.9
5.3.3
To select refrigerant branch kits
Refrigerant refnets
For piping example, refer to
"5.3.2 To select the piping size" on
▪ When using refnet joints at the first branch counted from the
outdoor unit side, choose from the following table in accordance
with the capacity of the outdoor unit (example: refnet joint a).
Outdoor unit
capacity type (HP)
2 pipes
3 pipes
8~10
KHRQ22M29T9
KHRQ23M29T9
12~22
KHRQ22M64T
KHRQ23M64T
24~42
KHRQ22M75T
KHRQ23M75T
▪ For refnet joints other than the first branch (example refnet joint b),
select the proper branch kit model based on the total capacity
index of all indoor units connected after the refrigerant branch.
Indoor unit capacity
index
2 pipes
3 pipes
<200
KHRQ22M20T
KHRQ23M20T
200≤x<290
KHRQ22M29T9
KHRQ23M29T9
290≤x<640
KHRQ22M64T
KHRQ23M64T
≥640
KHRQ22M75T
KHRQ23M75T
▪ 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
2 pipes
3 pipes
<200
KHRQ22M29H
KHRQ23M29H
200≤x<290
290≤x<640
KHRQ22M64H
(a)
KHRQ23M64H
(a)
≥640
KHRQ22M75H
KHRQ23M75H
(a)
If the pipe size above the refnet header is Ø34.9 mm or
more, KHRQ22M75H is required.
INFORMATION
Maximum 8 branches can be connected to a header.
▪ How to choose an outdoor multi connection piping kit. Choose
from the following table in accordance with the number of outdoor
units.
Number of outdoor units
Branch kit name
2
BHFQ22P1007
3
BHFQ22P1517
INFORMATION
Reducers or T-joints are field supplied.
NOTICE
Refrigerant branch kits can only be used with R410A.
5.3.4
About the piping length
Make sure the piping installation does not exceed the maximum
allowable pipe length, the allowable level difference, and the
allowable length after branching. To illustrate the piping length
requirements, 6 cases are discussed in the chapters below. They
describe both standard and non-standard outdoor unit combinations.
Definitions
Term
Definition
Actual piping length
Pipe length between outdoor
(a)
and indoor
units
Equivalent piping
length
Pipe length between outdoor
(a)
and indoor
units, including the equivalent length of the
piping accessories
Total piping length
Total piping length, from the outdoor to all
indoor units
(a)
If the system is a multi outdoor installation, re-read "the first
outdoor unit branch as seen from the indoor unit".
Equivalent length of the piping accessories
Accessory
Equivalent length
Refnet joint
0.5 m
Refnet header
1 m
Single BS1Q100~160
4 m
Single BS1Q25
6 m
Multi BS4~16Q14
4 m
Allowable height difference
Term
Definition
Distance
Actual piping length Pipe length between
outdoor
(a)
and indoor units
165 m
Equivalent piping
length
(b)
Pipe length between
outdoor
(a)
and indoor units
190 m
Total piping length Total piping length from the
outdoor
(a)
to all indoor units
300 m
