Capacity Multipliers As A Function Of Suction Line Size & Equivalent Length; Losses From Suction Line Elbows (Equivalent Length, Ft.); Evaporator Unit With Inverted Vapor Loop - Goodman GSH Series Service Instructions Manual

SERVICING
• The distance between the condenser and evaporator in
a completely horizontal installation in which the indoor
and outdoor unit do not differ more than 10 feet in
vertical distance from each other can approach 150
feet, as long as the equivalent length does not exceed
150 feet.
4. Two-Stage Condensing Unit: The maximum length of
tubing must not exceed 75 feet here indoor coil is located
above the outdoor unit.
NOTE: When the outdoor unit is located above the
indoor coil, the maximum vertical rise must not exceed
25 feet. If the maximum vertical rise exceeds 25 feet,
premature compressor failure will occur due to inad-
equate oil return.
5. Vibration and Noise: In long line applications, refrigerant
tubing is highly prone to transmit noise and vibration to the
structure it is fastened to. Use adequate vibration-isolat-
ing hardware when mounting line set to adjacent struc-
ture.
Most refrigerant tubing kits are supplied with 3/8"-thick
insulation on the vapor line. For long line installations over 50
feet, especially if the line set passes through a high ambient
temperature, ½"-thick suction line insulation is recommended
to reduce loss of capacity. The liquid line should be insulated
if passing through an area of 120°F or greater. Do not attach
the liquid line to any non-insulated portion of the suction line.
Table 9 lists multiplier values to recalculate system-cooling
capacity as a function of a system's equivalent line length (as
calculated from the suction line) and the selected suction
tube size. Table 10 lists the equivalent length gained from
adding bends to the suction line. Properly size the suction
line to minimize capacity loss.
REFRIGERANT LINE LENGTH (Ft)
0-24
Cond
Unit
Tons Suct Liq
1 1/2 5/8 1/4
2 5/8 1/4
2 1/2 3/4 3/8
3 3/4 3/8
3 1/2 3/4 3/8
4 7/8 3/8
5 7/8 3/8
*7/8" required for full ratings
**1 1/8" required for full ratings
***Lines greater than 74 feet in length or vertical elevation changes more than 50 feet, refer to the long
line set.
TABLE 10. CAPACITY MULTIPLIERS AS A FUNCTION OF
SUCTION LINE SIZE & EQUIVALENT LENGTH
58
25-49 50-74***
Line Diameter (In. OD)
Suct Liq Suct
3/4 3/8 3/4
3/4 3/8 3/4
3/4* 3/8 7/8
3/4** 3/8 7/8**
7/8** 3/8 1 1/8
1 1/8 3/8 1 1/8
1 1/8 3/8 1 1/8
Table 9
Nominal Vapor line
capacity diameter
Btuh (in.)
18,000 3/4
24,000 3/4
30,000 3/4
3/4
36,000
7/8
3/4
42,000
7/8
1-1/8
3/4
48,000
7/8
1-1/8
7/8
60,000
1-1/8
NOTE: For a condenser with a liquid valve tube connection
less than 3/8" diameter, use 3/8" liquid line tubing for a line
set greater than 25 feet.
TABLE 11. LOSSES FROM SUCTION LINE ELBOWS
(EQUIVALENT LENGTH, FT.)
Type of elbow fitting
90° short radius
90° long radius
45°
Installation Requirements
1. In a completely horizontal installation with a long line set
where the evaporator is at the same altitude as (or slightly
below) the condenser, the line set should be sloped
towards the evaporator. This helps reduce refrigerant
migration to the condenser during a system's off-cycle.
2. For a system installation where the evaporator is above
the condenser, an inverted vapor line trap should be
installed on the suction line just before the inlet to the
evaporator (see Fig 6). The top of the inverted loop must
be slightly above the top of the evaporator coil and can be
Liq
3/8 created simply by brazing two 90° long radius elbows
3/8
together, if a bending tool is unavailable. Properly support
3/8
and secure the inverted loop to the nearest point on the
3/8
indoor unit or adjacent structure.
3/8
3/8
3/8
Fig 6. Evaporator unit with inverted vapor loop
EQUIVALENT LINE LENGTH (FT)
50 75 100 125
.99 .97 .96 .95
1 .99 .99 .98
.98 .97 .96 .95
.93 .90 .86 .83
.98 .96 .94 .92
.93 .90 .87 .83
.97 .96 .94 .93
1 1 .99 .99
.90 .86 .82 .78
.96 .94 .93 .91
1 1 .99 .99
.93 .91 .89 .86
.99 .98 .98 .97
Table 10
I.D. (in.)
3/4 7/8 1-1/8
1.7 2
1.5 1.7
0.7 0.8
Table 11
150
.95
.97
.94
.79
.90
.80
.92
.98
N/R
.89
.98
.84
.97
2.3
1.6
1