The condensate line to my air handler is not graded properly, it's too long (30 ft) and I guess the low head pressure causes water to back up in the drain pan. Being an estimated 25+ years old the bottom of the air handler which must contain a GI drain pan is rusted. So there's a steady drip from the bottom of the rusted handler and if I don't purge some of the water from the line during hot days, it leaks faster from the air handler. My question is whether it could get to a point where the return air can pick up this condensate. I know that air must exchange heat with the evaporator coils, but I don't know what separates the air from water in the drain pan. Thanks in advance and thanks for this great site that has provided a lot of valuable info for me..