When installing chiller barrels, suction line sizing is very important. If suction line diameter is too small, you will see excessive pressure drops, which can cause a reduction in performance and inadequate compressor cooling. Too large of a diameter can reduce velocities enough that the oil will not remain entrained with the refrigerant and can cause oil to log in the evaporator and suction line.
Standard refrigeration suction lines are sized for long piping runs (100 ft). You may want to reduce line diameter one size for shorter runs.