Data Aire gForce DX - Air Cooled Unit Piping; Discharge Lines

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prevent oil and refrigerant migration back to the compressor during compressor off
cycles.
Piping should be designed with adequate three-dimensional flexibility. It should not be in
contact with the surrounding structure, unless a proper tubing mount has been installed. This
protection proves necessary to avoid excess vibration, which can ultimately result in
connection or tube failure due to fatigue or wear from abrasion. Aside from tubing and
connection damage, excess vibration may be transmitted to the surrounding structure and
generate an unacceptable noise level within the structure as well.
When piping, use copper tubing with appropriate supporting devices (supporting saddles, etc.).
All field piping must be installed according to local codes. Avoid piping runs through noise-
sensitive areas, such as office walls and conference rooms.
Piping and to the ASHRAE Refrigeration Handbook for general, good-practice refrigeration
piping.
All piping below the raised floor must be located so that it does not restrict airflow. Plan the
piping layout under the raised floor to prevent the airflow from being blocked. When installing
piping on the subfloor, it is recommended that the pipes be mounted in a horizontal plane
rather than stacked one above the other. Whenever possible, the pipes should be run parallel
to the airflow.
Ensure that the tubing surfaces to be brazed are clean and that all burrs have been removed
from the ends of the tubes. Ensure that all loose material has been cleaned from inside the
tubing before brazing. Keep piping clean and dry, especially on units with R-410A refrigerant.
The units may be ordered with top or bottom connections.
Air Cooled Unit Piping
Air-cooled unit piping is crimped and brazed closed from the factory and contains a nitrogen
holding charge. Each installation requires field-supplied refrigerant piping to a condenser.
Refer to section 2.14 Recommended Line Sizing, Air Cooled Units for a guideline on sizing
refrigerant lines. The ultimate responsibility for line size selection is that of the installing
contractor or design engineer. Data Aire does not assume this responsibility. The chart covers
distances up to 200 equivalent feet (61 m). For installations beyond this distance, consult
ASHRAE or similar references.
NOTE: Standard piping practice must be used to ensure proper oil return
and efficient operation. The interconnecting lines to the remote air-cooled
condenser or condensing unit must be installed by a qualified refrigeration
mechanic.
Discharge Lines
Discharge lines, also called hot gas lines, should be trapped at the top (inverted) and bottom
as well as every 15 to 20 feet (4.6 to 6.1 m) of vertical rise. Discharge check valves are
required on all installations, especially those where there are long pipe runs or cold climates.