Although there are various line lift, sizing, and trapping guidelines depending on oil and refrigerant type, there is one guideline we can all understand easily and remember to apply. This guideline is to slope suction lines towards condensing units/compressors.

Keeping the suction line sloped toward the compressor, especially with long overhead lines, helps return the oil. Proper oil return assists with capacity and lubrication, resulting in fewer issues.

A good general rule is to slope the suction line 1/2″ per 10′ of horizontal run.

Short and simple but often forgotten.

—Bryan