11
4.0 INSTALLATION
4.4.2.3 Maximum Liquid Pressure
Drop
The total liquid line pressure drop must not exceed
50 psig [345 kPa] to assure a solid column of liquid
at the metering device and stable control of super-
heat. Be sure to account for vertical separation,
elbows, filter driers, solenoid valves, sight glasses,
and check valves when calculating liquid line pres-
sure drop.
4.4.2.4 Liquid Line Refrigerant
Flashing
Excessive pressure drop and heat gain in long liquid
lines can result in the refrigerant flashing into a
vapor before it reaches the expansion device which
will dramatically reduce the capacity and efficiency
of the system. For this reason, the liquid line must
be sized properly using Table 2 and must be insulated
in unconditioned spaces.
4.4.2.5 Oil Level Adjustment for
Long Line Set Applications
Additional oil will need to be added if refrigerant is
added during installation. The following provides the
equation for the oil level adjustment and the compressor
name plate oil charge for the different outdoor units.
Tubing
Oil to be Added = [(Charge Adju OD
Unit Name Plate Refrigerant Charge (oz.)) ×
(0.022) – [(0.10) × (Compressor Name Plate Oil
Charge (oz.))]
Example:
An application requires 125ft of line set
with a liquid line diameter of 3/8”, Charge Adjustment =
66 oz., Name Plate Charge = 212 oz.,
Name Plate Oil Charge = 40 oz., Oil to be Added =
((66 oz. + 212 oz.) × .022) – (.10 × 40 oz.) = 2 oz.
OD Model
(-)A2024
(-)A2036
(-)A2048
(-)A2060
ZPV0212E-ZE9-130
ZPV0212E-ZE9-130
ZPV0342E-ZE9-130
ZPV038CE-2E9-130
Compressor
Nameplate Oil
Charge (oz)
40
40
40
40
4.4.2.6 Capacity Losses
Long line lengths can result in a reduction in
capacity due to suction line pressure drop and heat
gain or loss. Refer to Table 2 for capacity loss
multipliers for various suction line diameters and
equipment line lengths. This table does not ac-
count for any capacity loss due to heat gain or loss
from the environment. It is extremely important
not to oversize the suction line to minimize capacity
loss at the expense of proper oil return. If the table
shows an “NR” for a particular suction line diameter
and length, or, if a suction line diameter is not listed,
oil return will not be adequate.
4.4.3 Line Set Length and Fitting Losses
Refrigerant tubing is measured in terms of actual
length and equivalent length. Actual length is used
for refrigerant charge applications. Equivalent
length takes into account pressure losses from
tubing length, fittings, vertical separation, accessories,
and filter driers. The table below references
different commonly used equivalent lengths.
Line Size
in [mm]
90 Short
Radius
Elbow
90 Long
Radius
Elbow
45
Elbow
Solenoid
Valve
Check
Valve
Sight
Glass
Filter
Drier
3/8 [9.53]
1.3 [0.40]
0.8 [0.24]
0.3 [0.09]
6 [1.83]
4 [1.22]
0.4 [0.12]
6 [1.83]
1/2 [12.71]
1.4 [0.43]
0.9 [0.27]
0.4 [0.12]
9 [2.74]
5 [1.52]
0.6 [0.18]
6 [1.83]
5/8 [15.88]
1.5 [0.46]
1 [0.30]
0.5 [0.15]
12 [3.66]
6 [1.83]
0.8 [0.24]
6 [1.83]
3/4 [19.05]
1.9 [0.58]
1.3 [0.40]
0.6 [0.18]
14 [4.27]
7 [2.13]
0.9 [0.27]
6 [1.83]
7/8 [22.23]
2.3 [0.70]
1.5 [0.46]
0.7 [0.21]
15 [4.57]
8 [2.44]
1 [0.30]
6 [1.83]
1-1/8 [28.58]
2.7 [0.82]
1.8 [0.55]
0.9 [0.27]
22 [6.71]
12 [3.66]
1.5 [0.46]
6 [1.83]
Equivalent Length for Fittings: ft [m]
Table 1
