Technician arrived to perform a yearly friends and family club furnace maintenance two trane furnaces. Technician adjusted gas pressure, checked amps, checked static pressure, checked temperature differential, cleaned flame sensor, Changed filters and insured proper operation. While changing filters, technician noticed dirty ductwork and made estimates for the customer on getting them cleaned and sanitized along with surge protection for the units. Estimates have been emailed to the customer for further review. Both systems are heating properly at this time.