13
Tubing
Table 6B: Refrigerant Line Sizing Chart (Metric Units)
18 SEER2 Variable Speed Outdoor Units
Unit Size
Allowable
Liquid Line
Size
mm [in.]
Allowable
Vapor Line
Size
mm [in.]
Outdoor Unit ABOVE or BELOW Indoor Unit
Equivalent Length (Feet)
< 8 8-15 16-23 24-30 31-38 39-46
Maximum Vertical Separation / Capacity Multiplier
7.0 K W
[2.0 Ton]
*SEE
NOTE 3
6.35 [1/4] 15.88 [5/8] 8 / 1.00 15 / 0.99 10 / 0.98 2 / 0.97 NR NR
7.94 [5/16] 15.88 [5/8] 8 / 1.00 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96 15 / 0.95
9.53 [3/8] 15.88 [5/8] 8 / 1.00 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96 15 / 0.95
6.35 [1/4] 19.05 [3/4] * 8 / 1.00 15 / 0.99 10 / 0.99 2 / 0.99 NR NR
7.94 [5/16] 19.05 [3/4] * 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.98
9.53 [3/8] 19.05 [3/4] * 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.99 15 / 0.98
10.6 KW
[3 Ton]
7.94 [5/16] 15.88 [5/8] 8 / 0.99 15 / 0.97 15 / 0.95 15 / 0.93 11 / 0.91 NR
9.53 [3/8] 15.88 [5/8] 8 / 0.99 15 / 0.97 15 / 0.95 15 / 0.93 15 / 0.91 NR
7.94 [5/16] 19.05 [3/4] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 11 / 0.97 6 / 0.96
9.53 [3/8] 19.05 [3/4] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96
12.7 [1/2] 19.05 [3/4] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96
14.1 K W
[4 Ton]
9.53 [3/8] 19.05 [3/4] 8 / 0.99 15 / 0.98 15 / 0.96 15 / 0.95 15 / 0.93 15 / 0.92
12.7 [1/2] 19.05 [3/4] 8 / 0.99 15 / 0.98 15 / 0.96 15 / 0.95 15 / 0.93 15 / 0.92
9.53 [3/8] 22.23 [7/8] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.98 15 / 0.97
12.7 [1/2] 22.23 [7/8] 8 / 1.00 15 / 0.99 15 / 0.99 15 / 0.98 15 / 0.98 15 / 0.97
17.6 K W
[5 Ton]
**SEE
NOTE 4
9.53 [3/8] 19.05 [3/4] 8 / 0.98 15 / 0.97 15 / 0.95 15 / 0.93 14 / 0.91 NR
12.7 [1/2] 19.05 [3/4] 8 / 0.98 15 / 0.97 15 / 0.95 15 / 0.93 15 / 0.91 NR
9.53 [3/8] 22.23 [7/8] 8 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 / 0.96 12 / 0.95
12.7 [1/2] 22.23 [7/8] 8 / 0.99 15 / 0.99 15 / 0.98 15 / 0.97 15 /0.96 15 / 0.95
9.53 [3/8] 28.58 [1-1/8] ** 8 / 1.00 15 / 1.00 15 / 1.00 15 / 0.99 15 / 0.99 12 / 0.99
12.7 [1/2] 28.58 [1-1/8] ** 8 / 1.00 15 / 1.00 15 / 1.00 15 / 0.99 15 / 0.99 15 / 0.99
Notes:
1) Do not exceed 46 meters linear line length.
2) Do not exceed 15 meters vertical separation between indoor and outdoor units.
3) * 19.05mm [3/4 in.] vapor line should only be used for 2 ton systems if outdoor unit is below or at same level
as indoor unit to assure proper oil return.
4) ** 28.58mm [1-1/8 in.] vapor line should only be used for 5 ton systems if outdoor unit is below or at same
level as indoor unit to assure proper oil return.
5) Always use the smallest liquid line allowable to minimize refrigerant charge.
6) Applications shaded in light gray indicate capacity multipliers between 0.90 and 0.96 which are not
recommended, but are allowed.
7) Applications shaded in dark gray are not recommended due to excessive liquid or suction pressure drop.