Upon arrival to scheduled system maintenance I was shown to a A/H unit located horizontally in the attic space. 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 at this time with pictures uploaded to service titan. All electrical components connections are secure and readings are within range of factory specifications. Viewed attic insulation levels and duct work. Both are adequate at this time. The UV light purification system inside the air handler cabinet is needing a bulb replacement at this time. The indoor blower housing. It needs to be pulled and clean due to significant dust and debris buildup. The homeowner is currently having work done throughout the home, and would like to have both completed at the same time after all the renovations are completed. Collected temperature differentials in both heating and cooling modes. In the cooling mode had a 21° delta T