4
Connect Refrigerant Lines
Refrigerant lines must be connected by a licensed, EPA certified
refrigerant technician in accordance with established procedures.
IMPORTANT:
■
Connecting refrigerant lines must be clean, dehydrated,
refrigerant-grade copper lines. Heat pumps should be
installed only with specified line sizes for approved system
combinations with elevation differences up to 15 ft (4.6 m)
and total length of up to 50 ft (15.2 m). See the Suction Line
Sizes and Liquid Line Sizes charts.
■
Sharp bends or possible kinking in the lines will cause a
reduction in performance.
■
To avoid contamination of the refrigerant system, do not
remove the caps from the lines or system connection points
until connections are ready to be completed.
1. Route the suction and liquid lines from the fittings on the
indoor coil to the fittings on the heat pump. Run the lines in
as direct a path as possible, avoiding unnecessary turns and
bends.
2. For product efficiency, be sure that the suction line is
insulated over the entire exposed length and that both
suction and liquid lines are not in direct contact with floors,
walls, ductwork, floor joists, or other piping.
3. Remove valve cores.
4. Wrap the service valves with a wet rag.
5. Connect the suction and liquid lines, using a brazing
compound. Braze with an alloy of silver or copper and
phosphorus with a melting point above 1,100°F (593ºC).
NOTE: Do not use soft solder.
6. Make sure indoor coil has been put in place according to the
Installation Instructions and is connected to the refrigerant
lines.
7. Replace valve cores.
8. Pressurize the lines and indoor coil with a pressure not to
exceed 20 psi.
9. Leak test the lines with a pressure not to exceed 20 psig.
10. Evacuate the indoor coil and lines to a minimum of
500 microns to remove contamination and moisture, then
disconnect the vacuum pump.
11. Open the suction and liquid service valves fully.
12. Insulate the suction line with refrigerant line insulation
material of
¹⁄₄
" (6.4 mm) or more wall thickness.
13. Pack insulating material around refrigerant lines where they
penetrate the structure to protect the lines and to minimize
vibration transmission.
Suction Line Sizes
Installations exceeding 100 ft (30.5 m) are not recommended.
Liquid Line Sizes
Installations exceeding 100 ft (30.5 m) are not recommended.
A. Insulating material around refrigerant lines
Btu/h
Line Set Size—in. (cm) OD
18,000
³⁄₄
(1.9)
³⁄₄
(1.9)
³⁄₄
(1.9)
24,000
³⁄₄
(1.9)
³⁄₄
(1.9)
³⁄₄
(1.9)
30,000
³⁄₄
(1.9)
³⁄₄
(1.9)
³⁄₄
(1.9)
36,000
⁷⁄₈
(2.2)
⁷⁄₈
(2.2)
⁷⁄₈
(2.2)
42,000
⁷⁄₈
(2.2)
⁷⁄₈
(2.2)
⁷⁄₈
(2.2)
48,000
⁷⁄₈
(2.2)
⁷⁄₈
(2.2)
⁷⁄₈
(2.2)
60,000
1
¹⁄₈
(2.9)
1
¹⁄₈
(2.9)
1
¹⁄₈
(2.9)
Line Set
Length
Less than 25 ft
(7.6 m)
25 ft
(7.6 m)
Over 25 ft (7.6 m) and up
to 50 ft (15.2 m)
Btu/h
Line Set Size—in. (cm) OD
18,000
³⁄₈
(1)
³⁄₈
(1)
³⁄₈
(1)
24,000
³⁄₈
(1)
³⁄₈
(1)
³⁄₈
(1)
30,000
³⁄₈
(1)
³⁄₈
(1)
³⁄₈
(1)
36,000
³⁄₈
(1)
³⁄₈
(1)
³⁄₈
(1)
42,000
³⁄₈
(1)
³⁄₈
(1)
³⁄₈
(1)
48,000
³⁄₈
(1)
³⁄₈
(1)
³⁄₈
(1)
60,000
³⁄₈
(1)
³⁄₈
(1)
³⁄₈
(1)
Line Set
Length
Less than 25 ft
(7.6 m)
25 ft
(7.6 m)
Over 25 ft (7.6 m) and up
to 50 ft (15.2 m)
A
