Preformed system maintenance on two systems with climate care discount. The newer American standard has good refrigerant charge and temperature split at the supply and return vents. All electricals are in normal operating range and the system is running smoothly and efficiently. The older trane unit also has good refrigerant charge and temperature split. Its electricals are in normal operating range, though are on the higher end of the scale. Thos is nothing to worry about now but is the 19 year old system showing its age and not running at top efficiency. I also spoke with the homeowner about a lack of float switch on the older unit aswell as a blow out access. Aswell as one room not cooling as effectively on the system.