
20
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.
2.11. 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 f
or 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.
2.12. 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.