Performed maintenance on 2007 and 2019 system. Systems seem like they may run a lot. Checked several items to ensure home is conditioning as efficiently as possible. Air filters were restricted and in need of replacement. Cleared drain lines. Checked superheat and subcooling, refrigerant pressures were great. No problems were detected with the equipment at this time. Replacement of the downstairs unit will greatly improve the overall efficiency of the home, but there are other factors to consider. When able having another layer of insulation blown into the attic spaces should be the first move, then replacing widows. After attic is re-insulated, windows are updated, and the downstairs system is replaced the air quality in the home will be dramatically improved and power bill will never be the same again.