Tech found that bathroom ventilation fan had to damper installed in collar and was allowing outdoor ambient air to draft into the room. Exhaust fan is installed within six inches of supply vent in small bathroom area (see photo), likely causing the supply vent to sweat. Advised customer to call an electrician to replace exhaust assembly or install a collar with damper. Tech replaced upstairs and downstairs air filters. Tech observed that condenser unit is slightly off-level (see photo) but not a severe issue at this time. System is running normally at this time.