Upon arrival i was shown to an A/H unit in an attic that needed preventative maintenance. I immediately took off panel door to inspect all electrical components amp draw and voltage readings, as well as check the evap coil. Evap coil was clean but the blower housing and all electrical components were heavily covered in bio growth. Made sure all amps and voltages were within range, and suggested that we install a pure air X to negate bio growth and to ensure the life of the system. Installed pure air X uv light. Went around back the the C/U to check all electrical components amp draw and voltage readings as well as check the Freon levels. Freon levels were within range and all electrical components are working to factory specs. I put a vacuum on end of drain line and ensured drain was working properly with unit in operation. Unit is cooling very well.