Upon arrival to scheduled system maintenance I was shown to an A/H unit located in the attic space. Then immediately pulled panel doors off the unit to inspect all electrical connections, collect electrical readings and check the evap coil for cleanliness. Evaporator coil is clean with pictures uploaded to ST. All electrical components connections are secure with amp draw/voltage readings running within range of factory specifications.. collected temperature differentials in the heating and cooling modes. In the cooling mode had a 22° delta T at this time. Upon duct and insulation inspection, I found the attic to be extremely under insulated, in some areas of the attic it is completely bare of insulation. I highly recommend blowing in more insulation to ensure the system runs at peak efficiency, and to lower power consumption. Went to the side of the house to the C/U to verify system refrigerant charge, inspect all electrical components connections, collect electrical readings, an