AC precision tune up. Clean and tune up AC; cleaned condenser coil, checked all outdoor electrical components, tested indoor air flow, checked refrigerant levels, and tested overall AC operation. Found system cooling poorly. System is low on refrigerant. This means system has a refrigerant leak. Refrigerant can be added with sealant, but it is a bandaid fix, no guarantee. Can also not guarantee system will maintain set point with the issues I found. Motor starter and start assist are also showing evidence of failure. Replacement of the AC and furnace is recommended.