Fujitsu Airstage ASUB18TLAV1 - Page 589

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Selection of pipe size
*a b b1 c d e1 e2 f1 f2 f3
Liquid pipe
in. (m)
3/8"
(9.52)
3/8"
(9.52)
1/4" (6.35)
3/8"
(9.52)
3/8"
(9.52)
1/4" (6.35) 1/4" (6.35) 1/4" (6.35) 1/4" (6.35) 1/4" (6.35)
Gas pipe
in. (m)
3/4"
(19.05)
3/4"
(19.05)
1/2"
(12.70)
5/8"
(15.88)
5/8"
(15.88)
1/2"
(12.70)
1/2"
(12.70)
1/2"
(12.70)
1/2"
(12.70)
1/2"
(12.70)
Length ft. (m)
Example
196 (60) 49 (15) 32 (10) 49 (15) 16 (5) 32 (10) 16 (5) 32 (10) 16 (5) 32 (10)
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Pipe size "a" selection : The length that between outdoor unit and the farthest indoor unit.
a + b + c + f3 =326 ft. (100 m) > 295 ft. (90m)
Therefore Gas pipe must be size up from 5/8" (15.88 mm) to 3/4" (19.05 mm). (Refer 2-3. PIPE
SIZE)
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Limitation check
Diagram
Example
ft. (m)
Limitation
ft. (m)
Judge
Total pipe length Total 475 (145) 590 (180) or less OK
Between outdoor unit and farthest indoor unit a+b+c+f3 328 (100) 393 (120) or less OK
Between the rst separation tube and the farthest indoor unit b+c+f3 131 (40) 131 (40) or less OK
Between outdoor unit and the nearest indoor unit a+b1 229 (70) 16 (5) or more OK
Between outdoor unit and the rst separation tube a 196 (60) 9 (3) or more OK
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Calculation of additional charge refrigerant
1. Calculation of additional amount for pipe length
Liquid pipe size
in. (m)
3/8"
(9.52)
1/4"
(6.35)
Additional refrigerant
lbs./ft. (kg/m)
0.039
(0.058)
0.014
(0.021)
Liquid pipe length
ft. (m)
312 (95) 165 (50)
A = (0.039 x 311) + (0.014 x 164) = 14.48 (lbs.)
[(0.058 x 95) + (0.021 x 50) = 6.56 (kg)]
2. Factory charged amount
Model
Factory charged
amount lbs. (kg)
Outdoor unit AOU48 11.7 (5.30)
B = 11.7 (lbs.)
[
5.30 (kg)]
3. Total refrigerant amount check
C = A + B = 14.48 + 11.7 = 26.18 (lbs.) < 34.61 (lbs.) → OK
[6.56 + 5.30 = 11.86 (kg) < 15.70 (kg) → OK]
Check pipe length and height di󰀨erence between units by comparing with items shown in "2-2.PIPING
LIMITATION".
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