5 Preparation
Installer and user reference guide
12
RXYTQ8~16T7YF
VRV IV system air conditioner
4P388989-1B – 2016.02
D
Where there are no smaller room divisions:
E
Where there is a room division, but there is an opening
between the rooms sufficiently large to permit a free
flow of air back and forth.
a
b
a
Opening between the rooms
b
Partition (Where there is an opening without a door
or where there are openings above and below the door
which are each equivalent in size to 0.15% or more of
the floor area.)
3
Calculate the refrigerant density using the results of the
calculations in steps 1 and 2 above. If the result of the above
calculation exceeds the maximum concentration level, a
ventilation opening to the adjacent room shall be made.
Formula
F/G≤H
F
Total volume of refrigerant in the refrigerant
system
G
Size (m
3
) of smallest room in which there is
an indoor unit installed
H
Maximum concentration level (kg/m
3
)
4
Calculate the refrigerant density taking the volume of the room
where the indoor unit is installed and the adjacent room. Install
ventilation openings in the door of adjacent rooms until the
refrigerant density is smaller than the maximum concentration
level.
5.3
Preparing refrigerant piping
5.3.1
Refrigerant piping requirements
NOTICE
The refrigerant R410A requires strict cautions for keeping
the system clean, dry and tight.
▪ Clean and dry: foreign materials (including mineral oils
or moisture) should be prevented from getting mixed
into the system.
▪ Tight: R410A does not contain any chlorine, does not
destroy the ozone layer, and does not reduce earth's
protection against harmful ultraviolet radiation. R410A
can contribute slightly to the greenhouse effect if it is
released. Therefore we should take special attention to
check the tightness of the installation.
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant.
▪ 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 (mm)
Temper grade of piping material
≤15.9
O (annealed)
≥19.1
1/2H (half hard)
▪ All piping lengths and distances have been taken into
consideration (see
"5.3.4 About the piping length" on page 14
).
5.3.2
To select the piping size
Determine the proper size referring to 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
12~16
28.6
12.7
18~22
28.6
15.9
24
34.9
15.9
26~34
34.9
19.1
36~48
41.3
19.1
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 capacity
index
Piping outer diameter size (mm)
Gas pipe
Liquid pipe
<150
15.9
9.5
150≤x<200
19.1
200≤x<290
22.2
290≤x<420
28.6
12.7
420≤x<640
15.9
640≤x<920
34.9
19.1
≥920
41.3
Summary of Contents for RXYTQ8T7YF
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