6. SYSTEM DESIGN
Limitation check
Diagram
Example
ft (m)
Limitation
ft (m)
Judge
Total pipe length Total
259
(80)
Less than 377 (115)
OK
Between outdoor unit and the farthest indoor unit a + b + c + m
115
(35)
Less than 230 (70)
OK
Between outdoor unit and branch boxes a + b + c + d + e
121
(37)
Less than 180 (55)
OK
Between branch box and indoor unit
Total f + g + h + i + j + k + l + m
138
(43)
Less than 197 (60)
OK
Each unit f, g, h, i, j, k, l, m
16 to 26
(5 to 8)
Between 10 to 49
(3 to 15)
OK
Between outdoor unit and the first separation tube a
23
(7)
Greater than 16 (5)
OK
Calculation of additional charge refrigerant
Liquid pipe size
in. (mm)
1/4
(6.35)
3/8
(9.52)
Additional refrigerant
oz./ft. (g/m)
0.224
(21)
0.624
(58)
Liquid pipe length
ft (m)
138
(43)
121
(37)
Additional charge = (0.224 x 138) + (0.624 x 121) = 106.42 oz. = 6.65 lbs.
[Additional charge = (21 x 43) + (58 x 37) = 3049 g = 3.05 kg]
- (06 - 19) -
SYSTEM
DESIGN
SYSTEM
DESIGN