14
REFRIGERANT LINES
General refrigerant line sizing:
1 The outdoor units are shipped with a full charge of R410A
refrigerant. All charges, line sizing, and capacities are based on
runs of 25 ft. (7.6 m) per number of zones. For runs over 25 ft.
(7.6 m), consult long−line section on this page for proper
charge adjustments.
2 Minimum refrigerant line length between the indoor and
outdoor units is 10 ft. (3 m).
3 Refrigerant lines should not be buried in the ground. If it is
necessary to bury the lines, not more than 36−in (914 mm)
should be buried. Provide a minimum 6−in (152 mm) vertical
rise to the service valves to prevent refrigerant migration.
4 Both lines must be insulated. Use a minimum of 1/2−in.
(12.7 mm) thick insulation. Closed−cell insulation is
recommended in all long−line applications.
5 Special consideration should be given to isolating
interconnecting tubing from the building structure. Isolate
the tubing so that vibration or noise is not transmitted into
the structure.
IMPORTANT: Both refrigerant lines must be insulated separately.
S Table 6 provides the maximum lengths allowed:
Table 6—Piping and Refrigerant
SYSTEM SIZE 36K 48K
PIPING
Min. Piping Length ft(m) 10(3) 10(3)
Standard Piping Length ft(m) 25(7.5) 25(7.5)
Max. outdoor-indoor height difference (OU higher than IU) ft(m) 98(30) 98(30)
Max. outdoor-indoor height difference (IU higher than OU) ft(m) 98(30) 98(30)
Max. Piping length with no additional refrigerant charge ft(m) 26(8) 26(8)
Max. Piping Length ft(m) 213(65) 213(65)
Additional refrigerant charge
(between Standard - Max piping length)
Oz/ft(g/m) 0.43(40) 0.43(40)
Gas Pipe (size-connection type) in(mm) 5/8(16) 5/8(16)
Liquid Pipe (size-connection type) in(mm) 3/8(9.52) 3/8(9.52)
REFRIGERANT
Refrigerant Type -- R410A R410A
Charge Amount Lbs(kg) 6.72(3.05) 9.26(4.2)
Long Line Applications,:
1 No change in line sizing is required.
2 Add refrigerant per Table 7.
Table 7—Additional Charge Table Per Zone
UNIT SIZE
TOTAL LINE
LENGHT ft
ADDITIONAL CHARGE, oz/ft. Ft (m)
Min Max
>10-25
(3-8)
>25-213
(8-65)
36
10 213 None 0.43
48