Allowable Length/Height Difference Of Refrigerant Piping - Toshiba MMU-AP0072H2UL Engineering Data Book

3
Refrigerant piping design
3-2. Allowable length/height difference of
refrigerant piping
3-2-1. Heat recovery
Header unit(A)
(a)
Branching joint
for outdoor units
Main
piping
L1
First branching
H1
section
Height difference
between outdoor
and indoor units:
H1
≤ 165 ft (50 m)
(If the outdoor unit is
L3
installed in a higher
position than indoor unit)
Indoor unit connecting pipe
System restrictions
Max. No. of combined outdoor units
Max. capacity of combined outdoor units
Max. No. of connected indoor units
Max. capacity of combined indoor units
Allowable length and height difference of refrigerant piping
Total extension of pipe (Liquid pipe)
Farthest piping length L (*2)(*4)
Main piping length
Pipe length
Farthest equivalent piping length from the first
branch Li (*2)
Farthest equivalent piping length between outdoor units LO (*2)
Maximum equivalent piping length of pipes connected to outdoor units
Maximum actual length of pipes connected to indoor units
Maximum actual length between FS unit and indoor unit
Maximum equivalent length between branching sections
Height between outdoor and indoor units H1
Height difference
Height between indoor units H2
Height between outdoor units H3
<In case of two or more indoor units are connected with FS unit>
Max. equivalent piping length in group of the FS unit
Maximum actual length between FS unit and the wired indoor unit (*3)
Height difference between indoor units in same FS unit H4
*1: If "Medium Static Ducted Type (MMD-AP***BH)" is included in the system: Total indoor capacity code must be between 80% and 120% of the capacity of the outdoor unit.
*2: Farthest outdoor unit from the first branching section: Follower unit (C). Farthest indoor unit from the first branching section: indoor unit (o).
*3: If FS unit is connected to multiple indoor units, connect wires of FS unit to one of the indoor unit with main remote control.
*4: Allowable values for length equivalent to furthest pipe are shown below and they vary according to capacity rank of outdoor unit.
072 to 120 type: Equivalent length 605 ft (185 m), Actual length: 540 ft (165 m)
144 to 240 type: Equivalent length 640 ft (195 m), Actual length: 575 ft (175 m)
288 to 336 type: Equivalent length 656 ft (200 m), Actual length: 591 ft (180 m)
Outdoor units
Follower unit(C)
Follower unit(B)
Height difference
between outdoor units
H3
(c)
(b)
H3
Lb
La Lc
LA
Farthest equivalent piping length
between outdoor units: LO ≤ 49 ft (15 m)
Branching pipe L2
FS unit connecting pipe
a
b
FS unit FS unit
g
f
Indoor unit
The longest piping length:
The longest piping length from the first branchi:
Max.equivalent piping length in group of the FS unit:
L5 L6
L4
d e
FS unit
FS unit
FS unit
j
i
Indoor unit
3 units
28 ton
48 units
H2 ≤ 49 ft (15 m) 125% (*1)
H2 > 49 ft (15 m)
Equivalent length
Equivalent length
H2 > 9.8 ft (3 m)
Equivalent length
H2 ≤ 9.8 ft (3 m)
H1 > 9.8 ft (3 m)
H1 ≤ 9.8 ft (3 m)
Upper outdoor units
Lower outdoor units
Upper outdoor units
Lower outdoor units
≤ 0.3ft (0.1 m)
Branching header
Y-shape branching joint
L8
c
FS unit k
h
(Cooling only)
L
≤ 656 ft (200 m)
Li ≤ 215 ft (65 m)
Ln
≤ 98 ft (30 m)
L7
m
n
(m) (n)
Caution for installation
Note 1) Install the outdoor units in order of their capacity codes. A (header unit) ≥ B ≥ C
Note 2) The header unit is connected to the branching joint for outdoor unit which is
directly connected to the main pipe.
Note 3) Y-shaped branching joint must be installed horizontally.
Note 4) Make sure to connect the T-shaped branching joint of liquid pipe as <Fig1>.
105%
Do not connect the T-shaped branching joint as <Fig2>.
Allowable value (ft (m))
Actual length 985 (300)
656 (200)
Actual length 591 (180)
330 (100)
Actual length 280 (85)
395 (120)
Actual length 330 (100)
165 (50)
215 (65)
49 (15)
33 (10)
98 (30)
49 (15)
165 (50)
165 (50)
98 (30)
130 (40)
9.8 (3)
0.3 (0.1)
98 (30)
49 (15)
1.6 (0.5)
24
l
(Cooling only)
H2
o
Height difference between indoor units:
Height difference
between indoor units H2
≤ 130 ft (40 m)
in same FS unit:
(If the outdoor unit is installed in
H4 ≤ 1.6 ft (0.5 m) a higher position than indoor unit)
(o)
H4
Pipes
La + Lb + Lc + LA + L1 + L2 +L3 + L4 + L5 + L6 + L7 + L8 +
a + b + c + d + e + f + g + h + i + j + k + l + m + n + o
Lc + LA + L1 + L3 + L4 + L5 + L6 + L7 + o
L1
L3 + L4 + L5 + L6 + L7 + o
Lc + LA (Lb + LA)
La, Lb, Lc
a + f, b + g, c + h, d + i, e + j, k, l
f, g, h, i, j
–
–
–
–
–
–
L5 + L6 + m, L5 + L6 + L7 + n, L5 + L6 + L7 + o
L6 + m, L6 + L7 + n, L6 + L7 + o
–