14 Piping installation
Installation and operation manual
19
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ heat pump
4P546220-1C – 2020.10
Size up
HP class
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
12+14
28.6
(b)
12.7 → 15.9
16
28.6 → 31.8
(a)
18~22
15.9 → 19.1
24
34.9
(b)
26~34
34.9 → 38.1
(a)
19.1 → 22.2
36~54
41.3
(b)
(a)
If the size-up size is NOT available, you must use the standard
size. Sizes bigger than the size-up size are NOT allowed. But
even if you use the standard size, the equivalent piping length is
allowed to be more than 90 m.
(b)
Pipe size-up is NOT allowed.
▪ The pipe thickness of the refrigerant piping shall comply with the
applicable legislation. The minimal pipe thickness for R410A
piping must be in accordance with the table below.
Pipe Ø (mm)
Minimal thickness t (mm)
6.4/9.5/12.7
0.80
15.9
0.99
19.1/22.2
0.80
28.6
0.99
34.9
1.21
41.3
1.43
▪ In case the required pipe sizes (inch sizes) are not available, it is
also allowed to use other diameters (mm sizes), taken the
following into account:
▪ Select the pipe size nearest to the required size.
▪ Use the suitable adapters for the change-over from inch to mm
pipes (field supply).
▪ The additional refrigerant calculation has to be adjusted as
mentioned in
"To determine the additional refrigerant
F: Piping between refrigerant branch kit and
branch selector box (BP box)
Pipe size for direct connection on branch selector box (BP*) 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 branch selector box (BP box)
and RA DX indoor 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
14.1.3
To select refrigerant branch kits
Refrigerant refnets
▪ 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
8+10
KHRQ22M29T9
12~22
KHRQ22M64T
24~54
KHRQ22M75T
▪ 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
<200
KHRQ22M20T
200≤x<290
KHRQ22M29T9
290≤x<640
KHRQ22M64T
≥640
KHRQ22M75T
▪ 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
<200
KHRQ22M29H
200≤x<290
290≤x<640
KHRQ22M64H
(a)
≥640
KHRQ22M75H
(a)
If the pipe size above the refnet header is Ø34.9 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
The RYYQ22~54 models, consisting of two or three RYMQ modules,
require a 3-pipe system. There is an additional equalising pipe for
such modules (in addition to the conventional gas and liquid piping).
This equalising pipe does not exist for RYYQ8~20 or RXYQ8~54
units.
The equalising pipe connections for the different RYMQ modules are
mentioned in below table.
RYMQ
Equalising pipe Ø (mm)
8
19.1
10~16
22.2
18+20
28.6
Deciding the equalising pipe diameter:
▪ In case of 3 multi units: the connection diameter of outdoor to
T‑joint has to be kept.
▪ In case of 2 multi units: the connection pipe has to have the
largest diameter.
There is never a connection of the equalising pipe with the indoor
units.
Example:
(free multi combination)
