Technician arrived to perform a yearly friends and family club furnace maintenance on a 2010 Lennox furnace. Technician adjusted gas pressure, checked amps, checked temperature differential, checked static pressure, cleaned flame sensor, change filter and insured proper operation. When changing the filter, technician noticed dirty ductwork and made estimates on duct cleaning, sanitation and UV lighting. Estimates have been emailed to the customer for further review. System is heating properly at this time.