Performed a seasonal precision tune up on cooling units. Chemically cleaned condenser coils, checked all outdoor electrical components, tested indoor air flow, checked refrigerant levels, and tested overall AC operation. Also performed two Air Exchanger precision tune ups. Remove filters and core to vacuum. Also clean cabinet interior. Inspect bearings on blower assembly. Install core and filters. Clean off outside hoods. Test operation of air exchanger. Lastly replaced both media air filters to provide clean air again. With the age of both pieces of equipment replacement is encouraged. All recommendations declined at this time.