Stulz CeilAir CW - Remote Air Cooled Condensers (AR Models); Remote Air Cooled Condensing Units (AHU Models)

35OCH0006F08/13/2024
CEILAIR
®
CW & DX IOM
2.6.1.4 REMOTE AIR COOLED CONDENSING UNITS AHU MODELS
CAUTION
Do not exceed the maximum line lengths for the system configurations listed below:
RCU with hot gas bypass 50 ft
Remote condensing unit 100 ft
Remote air cooled condenser 150 ft
Vertical runs are based on a total rise of 30 equivalent ft. For longer rises, individual calculations should be
made. Sizes assume the use of single risers; double rises may be necessary.
2.6.1.3 Remote Air Cooled Condensers (AR Models)
Systems utilizing air cooled condensers must not have a refrigerant line pressure drop over 14 psig across
the condenser and the interconnecting piping to the condenser sections.
NOTE Condenser Selection for Sub-cooling
Ensure proper condenser selection to maintain reasonable sub-cooling temperatures.
If the condenser is installed above the evaporator, the discharge line should include a P-trap at the lowest
point in the piping. The highest point in the discharge line should be above the condenser coil and should
include an inverted trap to help prevent oil and liquid from flooding back to the compressor during off cycles.
If the condenser is installed below the evaporator, an inverted trap the height of the evaporator coil is required
on the liquid line to help prevent oil and liquid from flooding back to the compressor during off cycles.
Refer to the refrigerant-appropriate Recommended Discharge Line Sizes table (Table 4 or Table 5),
Recommended Liquid Line Sizes table (Table 6 or Table 7) and Recommended Suction Line Sizes table (Table
8 or Table 9).
2.6.1.4 Remote Air Cooled Condensing Units (AHU Models)
When installing a remote condensing unit above the evaporator, the suction line should be P-trapped at the
evaporator.
When installing remote condensing units below the evaporator, the suction line should be trapped with
an inverted trap the same height as the evaporator coil. This prevents migration of liquid refrigerant to the
compressor during off cycles.
NOTE Condensing Unit Minimum Clearance
Do not exceed 15 ft of vertical distance when installing the condensing unit below the evaporator.
All suction lines must be insulated to prevent condensation from forming on the pipes. Refer to the
Recommended Suction Line and Recommended Liquid Line sizing tables.