Unit installation

8
2.0 PIPING
2.1 Split Air Cooled Unit Piping
Refer to the attached Line Sizing chart on page 24 for a guideline for sizing refrigerant lines. The
ultimate responsibility for line size selection is that of the installing contractor or project engineer. Data
Aire does not assume this responsibility. The chart covers distances up to 200 equivalent feet. For
installations beyond this distance, consult ASHRAE or similar references.
Standard piping practice must be used to ensure proper oil return and efficient operation.
The interconnecting lines to the remote air cooled condensing unit must be installed by a
qualified refrigeration mechanic.
The discharge, suction and liquid lines need to be refrigerant grade copper and in accordance with
local code. All refrigeration piping should be installed with high temperature brazed joints. When brazing,
a supply of nitrogen gas needs to be fed through the refrigerant lines. Be sure to open the other end of
the refrigerant line allowing the nitrogen to bleed off and not cause excess pressure buildup.
Data Aire recommends a silver/phosphorus/copper alloy with between 5% and 15% silver be used to
braze refrigerant line set to the indoor and outdoor units. Nitrogen needs to be flowing through the lines
to eliminate carbon deposit buildup on the inside of the joints which could contaminate the refrigerant
and restrict the metering device.
2.1.1 Liquid Lines
Liquid line size is determined by pressure drop and velocity. The liquid line pressure drop should not
exceed 5 PSI. The recommended velocity should be between 200 and 300 FPM. To avoid excessive
liquid line pressure drop, the air cooled condensing unit should be located above or at the same level as
the evaporator. Condensing unit installation more than ten feet below the evaporator should be avoided.
2.1.2 Suction Lines
This unit has the compressor in the condensing unit and requires field piping of liquid and suction lines.
Suction lines are trapped similarly to discharge lines. Common practice for suction line selection and
installation should be followed.