Daikin R-410A Installation Manual page 28

indoor unit
1
REFNET joint
A
One outdoor
REFNET header unit installed
Multiple outdoor
units installed
∗ In case of multiple outdoor units installed, re-read to
the first outdoor branch as seen from the indoor unit.
Actual pipe length
Between outdoor
Maximum and indoor units
Equivalent length
allowable
Total extension length
length
Between outdoor branch and indoor unit
Actual pipe length
(Only for multiple outdoor units)
Between outdoor and indoor units Difference in height
Allowable
Difference in height
height Between indoor and indoor units
length
Between outdoor and outdoor units Difference in height
Allowable length after the branch Actual pipe length
Refrigerant branch kit selection
Refrigerant branch kits can only be
used with R-410A.
Example of downstream indoor units
Pipe size selection
Caution
The thickness and material shall be selected in accordance with local code.
For an outdoor unit multi installation, make the settings in accordance with the
following figure.
Oil-equalizing line (part C)
Piping between outdoor
branch and outdoor unit (part B)
Piping between outdoor units and refrigerant
branch kit (part A)
How to calculate the additional refrigerant
to be charged
Additional referigerant to be charged R (lb.)
R should be rounded off in units of 0.1 (lb.).
NOTE:
If a negative result is gotten for R from the formula at right, no refrigerant
needs to be added.
Branch with REFNET joint
REFNET joint ( -
Outdoor unit A G
g
a b c d e f
H1
A B C D E F G
P
h i j k l m n
1 2 3 4 5 6 7 H2
8
Indoor units ( - )
1 8
Outdoor unit
REFNET joint ( -
A G
First outdoor H3
branch
a b c d e f g
H1
A B C E F G P
D
h i j k l m n
1 2 3 4 5 6 7 H2
8
Indoor units ( - )
1 8
Pipe length between outdoor and indoor units ≤ 492ft.
Example unit 8: a + b + c + d + e + f + g + p ≤ 492ft.
Equivalent pipe length between outdoor and indoor units ≤ 575ft. (assume equivalent pipe length of REFNET joint to be 1.6ft., that of REFNET header to be 3.3ft. calculation purposes)
Total piping length from outdoor unit* to all indoor units ≤ 950ft.
≤ 33ft.
Piping length from outdoor branch to outdoor unit Approximately length: max 43ft.
Difference in height between outdoor and indoor units (H1) ≤ 164ft.
Difference in height between adjacent indoor units (H2) ≤ 49ft.
Difference in height between outdoor unit (main) and outdoor unit (sub) (H3) ≤ 16ft.
Pipe length from first refrigerant branch kit (either REFNET joint or REFNET header ) to indoor unit ≤130ft.
Example unit 8: b + c + d + e + f + g + p ≤ 130ft.
How to select the REFNET joint
• 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.
Outdoor unit capacity type Refrigerant branch kit name
RXYQ72/96 KHRP26M22T, KHRP26M33T
RXYQ144/168/192 KHRP26M22T, KHRP26M33T, KHRP26M72TU
• For REFNET joints other than the first branch, select the proper branch kit model based on the total capacity
index.
indoor capacity index Refrigerant branch kit name
< 72 KHRP26M22T
72 ≤ x < 111
KHRP26M33T
111 ≤
KHRP26M72TU
example in case of REFNET joint C; indoor units 3 + 4 + 5 + 6 + 7 + 8
Piping between outdoor units and refrigerant branch kit (part A)
• Match to the size of the connection piping on the outdoor unit.
Outdoor unit connection piping size
Piping size
Outdoor unit capacity type
Gas pipe Liquid pipe
φ3/4 φ3/8
RXYQ72
φ7/8 φ3/8
RXYQ96
φ1-1/8 φ5/8
RXYQ144/168/192
Total length (ft.) Total length (ft.) Total length (ft.)
R= of liquid piping + of liquid piping + of liquid piping
×0.235 ×0.168
size at φ7/8 size at φ3/4 size at φ5/8
Total length (ft.) Total length (ft.)
+ +
of liquid piping of liquid piping
×0.036
size at φ3/8 size at φ1/4
Branch with REFNET joint and REFNET header
) Outdoor unit
REFNET joint (
i
a
A
b
H1
REFNET header
g
c d e f
1 2 3 4 5
Indoor units (
1
Outdoor unit
)
REFNET joint (
H3
i
a
A
H1 b
REFNET header
g
c d e f
1 2 3 4 5
Indoor units (
1
Example unit 6: a + b + h ≤ 330ft., unit 8: a + i + k ≤ 492ft.
(Max 130ft. if the outdoor unit is below)
Example unit 6: b + h ≤ 130ft., unit 8:i + k ≤ 130ft.
How to select the REFNET header
• Choose from the following table in accordance with the total capacity of all the indoor units connected below the REFNET
header.
In case of multiple outdoor units installed, use outdoor branch kit.
example in case of REFNET joint B indoor units 7 + 8,
example in case of REFNET header; indoor units 1 + 2 + 3 + 4 + 5 + 6
Piping between refrigerant branch kits
• Choose from the following table in accordance with the total capacity of all the
indoor units connected below this.
(Unit: in.)
• Do not let the connection piping exceed the refrigerant piping size chosen by
general system model name.
indoor capacity index
Gas pipe
φ5/8
< 72
72 ≤ x < 111 φ7/8
111 ≤ x < 156
φ1-1/8
156 ≤
Total length (ft.)
+ of liquid piping
×0.114 ×0.074
size at φ1/2
Model name
Amount of refrigerant
_
×0.015 RXYQ72/96
RXYQ144/168/192 6.6 lb.
Branch with REFNET header
Outdoor unit
• )
A B
a
B
k
j
7 8
H2
h b c
1 2
6
- )
8
Outdoor unit
• )
A B
a
B
k
j
7 8
H2
h
b c
6 1 2
- )
8
Example unit 8: a + i ≤ 492ft.
Outdoor unit
r
Example unit 8: i ≤ 130ft.
indoor capacity index Refrigerant branch kit name
< 72 KHRP26M22H (Max. 4 kit)
KHRP26M33H (Max. 8 kit)
< 111
111 ≤
KHRP26M72H (Max. 8 kit)
Number of outdoor units
2 units
example in case of REFNET header; indoor units 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8
Between refrigerant branch kit and indoor unit
• Pipe size for direct connection to indoor unit must be the same as the
connection size of indoor unit.
indoor capacity type
(Unit: in.)
Piping size
07, 09, 12, 18 type
Liquid pipe
24, 30, 36, 48 type
φ3/8
φ1/2
Piping between outdoor branch and outdoor unit (part B)
φ5/8
outdoor capacity type
RXYQ72
RXYQ96
Oil-equalizing line (Only for multiple outdoor units installed) (part C)
Piping size
Example for refrigerant branch using REFNET joint and REFNET header for RXYQ192
If the outdoor unit is
a: φ3/4 × 100ft. d: φ3/8 × 30ft.
RXYQ192 units and the
b: φ5/8 × 30ft. e: φ3/8 × 30ft.
piping lengths are as at
c: φ3/8 × 30ft. f : φ3/8 × 30ft.
right
R= 100 0.168 + 30 0.014 + 30 0.074 + 120 0.036 + 155 0.015 - 6.6 =22.485
0 lb.
a b i c+d+e+f g+h+j+k
REFNET header
H1
g
d e f h
i
3 4 5 6 7
H2
8
Indoor units ( - )
1 8
REFNET header
H3
H1
g
d e f h
3 4 5 6 7 H2 i
Indoor units ( - ) 8
1 8
r ≤ 33ft. (Approximately length: max 43ft.)
t ≤ 33ft. (Approximately length: max 43ft.)
t
Branch kit name
BHFP22M90U
(Unit: in.)
Piping size
Gas pipe Liquid pipe
φ1/2 φ1/4
φ5/8 φ3/8
(Unit: in.)
Piping size
Gas pipe Liquid pipe
φ3/8
φ3/4
φ7/8 φ3/8
(Unit: in.)
φ1/4
g: φ1/4 × 30ft. j : φ1/4 × 30ft.
h: φ1/4 × 70ft. k: φ1/4 × 25ft.
i : φ1/2 × 30ft.
22.5