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

gForce Ultra IOM
22
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.
Refer 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. For air-cooled units built
after 3/14/2017, the discharge check valves are already installed inside the evaporator section and do
not need to be installed external to the unit. For units built before this date, the check valves must be
field supplied and installed externally to the evaporator section.
If there is doubt as to whether the check valve is already installed in the unit, look for it on the hot gas
line close to the exit point of the unit (see example picture below). The externally installed check valve
should be placed from six (6) to ten (10) feet (1.8 to 3.1 m) from the compressor.