From what I was taught it's not condenstaion that's the problem, it's blower death you need to worry about. It is more dificult for the blower of a furnace to pull through a coil rather than push, by design the furnace is designed to push through the coil, so install it that way. Maybe my information is just someone else's opinion, but I still agree with the outcome, using equipment in the application it was intended for.