506253-01
Page 4
Issue 0912
Select line set diameters from Table 2 to ensure that oil return
to the compressor. Size vertical suction riser to maintain
minimum velocity at minimum capacity. Recommended line
length is 50’ or less. If more than 50’ line set is required,
contact Technical Services.
Table 2 shows the diameters for line sets up to 100’ although
vertical lift applications and trapping requirements need to
be reviewed with Technical Services for line sets over 50’.
Installing Refrigerant Line
During the installation of an air conditioning system, it is
important to properly isolate the refrigerant line to prevent
unnecessary vibration. Line set contact with the structure
(wall, ceiling, or floor) may cause objectionable moise when
vibration is translated into sound. As a result, more energy
or vibration can be expected. Close attention to line set
isolation must be observed. If refrigeration lines are routed
through a wall, seal and isolate the opening so vibration is
not transmitted to the building.
Following are some points to consider when placing and
installing a high-efficiency outdoor unit:
Placement
Be aware that some localities are adopting sound ordinances
based on how noisy the unit is at the neighbor’s home, not
at the original installation. Install the unit as far as possible
from the property line. When possible, do not install the unit
directly outside a bedroom window. Glass has a very high
level of sound transmission. Figure 4 shows how to place
the outdoor unit and line set to reduce line set vibration.
Line Set Isolation
Illustrations on the following pages demonstrate procedures
which ensure proper refrigerant line set isolation. Figure 5
shows how to install line sets on horizontal runs. On page
6, Figure 6 shows how to make a transition from horizontal
to vertical and Figure 7 shows how to install line sets on
vertical runs.
Brazing Connection Procedure
1.
Cut ends of refrigerant lines square (free from nicks or
dents). Debur the ends. The pipe must remain round; do
not pinch end of line.
2.
Before making line set connections, use dry nitrogen to
purge the refrigerant piping. This will help to prevent
oxidation and the introduction of moisture into the system.
3.
Use silver alloy brazing rods (5% or 6% silver alloy for
copper-to-copper brazing or 45% silver alloy for
Refrigerant Line Set Diameters (in.)
For installations exceeding 50’, contact
Technical Services.
Table 2
S uction L ine
B T U H
L ine S e t L e ngth a nd S iz e
12 ft.
25 ft. 50 ft. 75 ft. 100 ft.
3/4
3/4
24,000
7/8
36,000
7/8
7/8
7/8
1-1/8
7/8
7/8
1-1/8
48,000
7/8
7/8
7/8
1-1/8
1-1/8
60,000
1-1/8
1-1/8
7/8
1-1/8 1-1/8
L iquid L ine
B T U H
L ine S e t L e ngth a nd S iz e
12 ft.
25 ft. 50 ft. 75 ft. 10 0 ft.
3/8
3/8
3/8
3/8
3/8
24,000
3/8
3/8
3/8
3/8
3/8
3/8
3/8
1/2
36,000
3/8
3/8
3/8
1/2
48,000
60,000
1/2
1/2
1/2
Polyolester (POE) oils used with R-410A refrigerant
absorb moisture very quickly. It is very important that
the refrigerant system be kept closed as much as
possible. DO NOT remove line set caps or service valve
stub caps until ready to make connections.
WARNING
