18
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Piping installation
Installer and user reference guide
73
RXYLQ10~14T7Y1B*
VRV IV system air conditioner
4P543427-1A – 2020.10
Indoor unit capacity index
2 pipes
≥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.
18.1.5 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
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.
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).
