17
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Piping installation
Installer and user reference guide
61
RXYTQ
VRV IV+ heat pump for high ambient temperatures
4P561157-1B – 2021.11
▪
Only use phosphoric acid deoxidised seamless copper.
▪
Foreign materials inside pipes (including oils for fabrication) must be
≤30 mg/10 m.
▪
Temper grade: use piping with temper grade in function of the pipe diameter as
listed in table below.
Pipe Ø
Temper grade of piping material
≤15.9 mm
O (annealed)
≥19.1 mm
1/2H (half hard)
▪
All piping lengths and distances have been taken into consideration (see
"17.1.5 About the piping length"
64]).
17.1.2 Refrigerant piping insulation
▪
Use polyethylene foam as insulation material:
-
with a heat transfer rate between 0.041 and 0.052 W/mK (0.035 and
0.045 kcal/mh°C)
-
with a heat resistance of at least 120°C
▪
Insulation thickness
Ambient temperature
Humidity
Minimum thickness
≤30°C
75% to 80% RH
15 mm
>30°C
≥80% RH
20 mm
17.1.3 To select the piping size
Determine the proper size using the following tables and reference figure (only for
indication).
A
B
B
B
C
D
E
x
y
b
a
1
2
3
4
b
1,2,3,4
VRV DX indoor unit
a,b
Indoor branch kit
x,y
Outdoor multi connection kit
A, B, C: Piping between outdoor unit and (first) refrigerant branch kit
Choose from the following table in accordance with the outdoor unit total capacity
type, connected downstream.
Outdoor unit capacity
type (HP)
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
8
19.1
9.5
10
22.2
9.5
