5 Preparation
Installer and user reference guide
14
RXYTQ8~16U7YF
VRV IV+ heat pump for high ambient temperatures
4P561157-1 – 2018.09
a
Outdoor unit
b
Main pipes
c
Increase if the equivalent piping length is ≥90 m
d
First refrigerant branch kit
e
Indoor unit
Size up
HP class
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
8
19.1 → 22.2
9.5 → 12.7
10
22.2 → 25.4
(a)
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
36~48
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
"6.7.3 To determine the additional refrigerant
.
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
8+10
KHRQ22M29T9
12~22
KHRQ22M64T
24~48
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
Indoor unit capacity index
2 pipes
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
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 to perform the piping installation within the range of the
maximum allowable pipe length, allowable level difference and
allowable length after branching as indicated below.
Definitions
Term
Definition
Actual piping length
Pipe length between outdoor
(a)
and indoor
units.
Equivalent piping
length
(b)
Pipe length between outdoor
(a)
and indoor
units.
Total piping length
Total piping length from the outdoor
(a)
to all
indoor units.
H1
Difference in height between outdoor and
indoor units.
H2
Difference in height between indoor and
indoor units.
H3
Difference in height between outdoor and
outdoor units.
(a)
If the system capacity is >16 HP, re-read "the first outdoor
branch as seen from the indoor unit".
(b)
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).
5.3.5
Piping length: VRV DX only
For system only containing VRV DX indoor units:
