Also, keep in mind any dust that is on the evaporator coil fins will eventually wash down to the bottom of the coil where it sits in the drain pan. Over time the dust will build up enough at the bottom and the condensate will not make it to the pan but instead, will drain out onto the floor. Air filters don't catch everything. I see this situation in the field a lot.
2015 Jayco 24FBS Elite Jay Flight
2013 Chevrolet Silverado 2500HD 4X4 6.0L 3.73 Axle
HD Trailering Package with Integrated Brake Controller
Equal-i-zer Hitch 10k/1000