18
4.0 INSTALLATION
For applications with the outdoor unit below the
indoor coil, the following is required:
• Inverted vapor-line trap (Reference Figure 4)
• Insulated liquid line in unconditioned space only.
• Insulated vapor line full length.
• Follow the proper line sizing, maximum linear
and equivalent length, maximum vertical separa-
tion, charging requirements, and oil level adjust-
ments spelled out in this document.
• Measure pressure at the liquid line service valve
and prior to expansion device. Verify that the
pressure drop is not greater than 50 PSI [345
kPa].
• For elevations greater that 25’ [8 m] a lower sub-
cooling can be expected.
• Verify there is at least 5ºF [2.8ºC] of liquid sub-
cooling at the indoor coil prior to the expansion
device.
Tubing
4.5.2.2 Outdoor Unit Below Indoor Coil (Long Line Set Applications)
Figure 4
INVERTED TRAP
EVEN WITH TOP
OF THE COIL
REFERENCE TABLE 2 FOR
MAXIMUM LENGTH AND
VERTICAL SEPARATION LIMITATIONS
ST-A1219-02-01
INSULATE LIQUID LINE
IN UNCONDITIONED
SPACE FOR LONG
LINE APPLICATIONS
INSULATED VAPOR LINE FULL LENGTH
VERIFY LIQUID SUBCOOLING
PRIOR TO EXPANSION DEVICE
IN THE COOLING MODE.
