where is the a/c drain tube located

I have a 56 flying cloud and i want to have an a/c unit installed (Coleman Mach 8) . There was no a/c in the trailer so there was no drain tube. I need to install one but I'm not sure where to put it. I want condensation to drain out to the ground not down the sides of the trailer. The unit will be in the center vent. does the hose attach to the drain pan then out the hose ? BTW the inside skin is out so I have options.