Daikin VRV IV Q+ Series Installation And Operation Manual page 18

14 Piping installation
NOTICE
▪ Prepare a water drainage channel around the
foundation to drain waste water from around the unit.
During heating operation and when the outdoor
temperatures are negative, the drained water from the
outdoor unit will freeze up. If the water drainage is not
taken care of, the area around the unit might be very
slippery.
▪ When installed in a corrosive environment, use a nut
with plastic washer (a) to protect the nut tightening part
from rust.
a
14 Piping installation
14.1 Preparing refrigerant piping
14.1.1 Refrigerant piping requirements
NOTICE
Refrigerant R410A requires strict cautions for keeping the
system clean and dry. Foreign materials (including mineral
oils or moisture) should be prevented from getting mixed
into the system.
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant.
▪ 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
≥19.1 mm
▪ All piping lengths and distances have been taken into
consideration (see About the piping length in the installer
reference guide).
NOTICE
When existing field piping is re-used, the design pressure
of the piping has to be 33 bar (3.3 MPa) or higher.
NOTICE
Check also if the existing field piping (including branch
piping) is compatible with the unit in terms of materials and
thickness, and if the pipes and branch piping are not
corroded. If the existing field piping does not comply with
the above conditions, replace the existing field piping with
field piping that meets the specific conditions.
NOTICE
Check if there was no compressor malfunction or similar
issues that could contribute to piping problems in the past.
If there were such problems, check that the appropriate
repairs were made, and if not, perform such repairs.
Installation and operation manual
18
O (annealed)
1/2H (half hard)
INFORMATION
The RXYQQ unit will limit the pressure on the field piping
to 33 bar. Inside the outdoor unit, the design pressure is
40 bar.
14.1.2 To select the piping size
Determine the proper size using the following tables and reference
figure (only for indication).
A
a x
D
b c
E
1 2 3 4
1~4 VRV DX indoor unit
a,b,c 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 Piping outer diameter size (mm)
unit
Gas pipe
capacity
Standard
type (HP)
8 19.1
10 22.2
12~16 28.6
18~22 28.6
24 34.9
26~34 34.9
36~42 41.3
D: Piping between refrigerant branch kits
Choose from the following table in accordance with the indoor unit
total capacity type, connected downstream. Do not let the
connection piping exceed the refrigerant piping size chosen by the
general system model name.
Indoor unit Piping outer diameter size (mm)
capacity
Gas pipe
index
Standard
<150 15.9
150≤x<200 19.1
200≤x<290 22.2
(a)
290≤x<420 28.6
420≤x<640
640≤x<920 34.9
≥920 41.3
(a)
Ø25.4 applicable in case of 290≤x≤420, if available on the site.
Example:
▪ Downstream capacity for E=capacity index of unit 1
B B B
C
y
Liquid pipe
Max. Standard Max.
28.6 9.5 15.9
9.5
34.9 12.7
15.9 19.1
41.3 15.9
19.1 22.2
54.1 19.1
Liquid pipe
Max. Standard Max.
19.1 9.5 12.7
25.4
28.6 15.9
34.9 12.7
15.9 19.1
54.1 19.1 22.2
RXYQQ8~20U7Y1B
VRV IV Q+ series heat pump
4P546221-1B – 2020.10