Performed system maintenance. Found equipment operating slightly under charged. System has extremely long line set that goes underground approximately 60ft to home and then up into the attic. Needs approximately 2 lbs of 410a and recommended easy seal leak repair. Indoor equipment has no float safety switch present. This is installed in an effort keep any water damage from happening in the event the drain line gets clogged and over flows. This is a very common event. Return side of duct has been patched and repaired at some point, suggest to replace return of ductwork and seal supply plenum. Also provided option to replace the entire duct system.