To Select Refrigerant Branch Kits; About The Piping Length - Daikin VRV IV+ RYYQ12U7Y1B Series Installer And User Manual

G: Piping between BP unit and RA DX indoor unit
Only in case RA DX indoor units are connected.
Indoor unit capacity Piping outer diameter size (mm)
index
Gas pipe
20, 25, 30
50
60
71
5.3.3

To select refrigerant branch kits

Refrigerant refnets
For piping example, refer to "5.3.2 To select the piping size" on
page 13.
▪ 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)
8~10
12~22
24~54
▪ 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
<200
200≤x<290
290≤x<640
≥640
▪ 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
<200
200≤x<290
290≤x<640
≥640
(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
2
3
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.
RYYQ+RYMQ+RXYQ8~20U7Y1B
VRV IV+ heat pump
4P546228-1 – 2018.09
Liquid pipe
9.5 6.4
12.7
9.5
15.9
2 pipes
KHRQ22M29T9
KHRQ22M64T
KHRQ22M75T
2 pipes
KHRQ22M20T
KHRQ22M29T9
KHRQ22M64T
KHRQ22M75T
2 pipes
KHRQ22M29H
(a)
KHRQ22M64H
KHRQ22M75H
Branch kit name
BHFQ22P1007
BHFQ22P1517
RYMQ Equalising pipe Ø (mm)
8
10~16
18~20
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)
RYMQ8+RYMQ12+RYMQ18.
(RYMQ18); Ø22.2 (RYMQ12) and Ø19.1 (RYMQ8). In figure below
only equalising pipe is shown.
Ø28.6 mm Ø22.2 mm
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. Three patterns
will be discussed, including VRV DX indoor units combined with
Hydrobox units or RA DX indoor units.
Definitions
Term
Actual piping length Pipe length between outdoor
units.
Equivalent piping Pipe length between outdoor
(b)
length units.
Total piping length Total piping length from the outdoor
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.
H4 Difference in height between outdoor and
BP unit.
H5 Difference in height between BP unit and
BP unit.
H6 Difference in height between BP unit and
RA DX indoor unit.
(a) If the system capacity is a multi outdoor installation, 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 Preparation
19.1
22.2
28.6
Largest connection is Ø28.6
Ø19.1 mm
Definition
(a)
and indoor
(a)
and indoor
(a)
to all
Installer and user reference guide
15