FC Roof AC drain tubes for new units

[hifreqdude]

Hello, I am getting ready to replace the original ac units on our 78 FC with Coleman 15000 BTU Mach 8 low profile units.
My question would be to anyone with previous experience routing drain lines weighing in as to solutions.
I did read a thread wherein Randy Dupree indicated running lines to the vent stack, which I thought was a great idea, but I am thinking of using units with the condensation pumps and from what I can tell they come out inside the unit opening.
Should I just buy the standard units and affix a drain apparatus to the vents, I am pretty handy with many things and know i can figure it out on demand, just looking to expedite a plan or draw from this deep well of knowledge here before pulling the trigger, poised and ready.

[patticake]

Since you are handy, maybe you can reroute the drain area or put a drip pan under the drain and route it to the factory drain tube.
I really can't remember how mine was as I haven't owned an FC in over 13 years. Which, by the way, was a '78 with a rear bath.

[ernie ekberg]

older coaches had the condensate drain off the roof- my 84 was that way

[hifreqdude]

Thank you Steve and Ernie, I appreciate your responses guys, I have had the original units off when I first got the bus to service and reseal them, and found no drain tubes.
I really do not want to have them haphazardly drip wherever if possible. I will most likely construct a system of 1/2 ID PEX or something with tee's allowing them to drain fore and aft, or route them to the shower vent drain as Randy suggested in a post if someone does not have a better vision. I have begun stripping the armadillo plates and goat rails to inspect and refinish the roof.(Man! those things are heavy!) The roof looks great so far with the exception of one minor surface rust in one spot which is already Ospho'ed to turn it.