Refrigerant Line Considerations; Service Valve Connection Sizes; Refrigerant Line Sizes; Refrigerant Piping Limits And Required Refrigerant Line Length - ComfortStar 18 Installation Manual

5 REFRIGERANT LINE
CONSIDERATIONS

5.1 Service Valve Connection Sizes

Suction line
Models
connection
18/24/30/36 3/4
42/48/60/61 7/8
Table 5-1
Figure 5-1

5.2 Refrigerant Line Sizes

Suction Line
Models
optional standard
18/24/30/36 5/8 3/4
42/48
3/4 7/8
7/8 1-1/8
60/61
Table 5-2
5.3 Refrigerant Piping Limits And
Required Refrigerant Line
Length
Total equivalent length(Feet)
Liquid line
25 50
Model
(inches)
Maximum vertical length(Feet)
5/16 25 50
18
3/8 25 50
5/16 25 40
24
3/8 25 50
5/16 25 40
30
3/8 25 50
5/16 25 50
36
3/8 25 50
5/16 25 23
42
3/8 25 50
1/2 25 50
48
3/8 25 46
1/2 25 50
60/61
3/8 25 50
Table 5-3
Liquid line
connection
3/8
Liquid Line
optional standard
5/16
3/8
1/2
1/2
75 100 125 150
40 30 NA NA
45 40 NA NA
30 20 NA NA
45 40 NA NA
40 30 NA NA
50 50 NA NA
40 30 10 NA
60 60 40 30
4 N/A NA NA
43 36 30 24
56 55 40 30
38 30 22 15
60 60 40 30
56 44 32 20
04
Total suction line length
Suction
Model 25
(inches)
5/8 1.00 0.97
18
3/4 1.00 0.98
0.97
5/8 1.00
24
3/4 1.00 0.98
5/8 1.00 0.97
30
3/4 1.00 0.98
5/8 1.00 0.97
36
3/4 1.00 0.99
3/4 1.00 0.98
42
7/8 1.00 0.98
3/4 1.00 0.98
48
7/8 1.00 0.98
7/8 1.00 0.98
60/61
1 1/8 1.00 0.99
Table 5-4 Suction line length/size VS capacity multiplier
NOTE
Using suction line larger than shown in chart will
result in poor oil return and is not recommended.
For example: the system capacity published in
AHRI is 17800 Btu/h. This data is based on the
AHRI test condition and 25 feet line set with
standard suction tube size (3/4" tube). If you
need to add the line set more than 25 feet or use
the optional suction tube size, you need to
recalculate the capacity with the coefficient in the
table. For 50 feet line and 5/8" suction tube, the
capacity will be 17800*0.97=17266 Btu/h.
Determine required line length and lift. You will need this
later in Section 14.
Total Line Length = __________ Feet.
Total vertical Change(Lift) = __________ Feet.
Line Length
Figure 5-2

5.4 Refrigerant Line Insulation

NOTE
The suction line must always be insulated. DO
NOT allow the Liquid Line and Suction Line to
come in direct (metal to metal) contact.
50 100 150
Coefficient
0.94 N/A
0.95 N/A
0.94 N/A
0.95 N/A
0.94 N/A
0.96 N/A
0.94 0.90
0.97 0.96
0.95 0.93
0.97 0.96
0.95 0.92
0.97 0.96
0.94 0.9
0.97
0.98