Originally Posted by dogwood
Trying to add AC to 21 foot 1971 Globe Trotter. What do I need to know?
According to my notes, your coach should be pre-wired and braced for air conditioner installation and should have the built-in condesate drain tube(s) as well. Unlike competing brands, Airstream did not typically use existing vent openings for air conditioners installations. The electric cable is coiled in the cieling near the specified location for the opening as should be the condesate drain(s). An Airstream dealer, Airstream Service Center, or Airstream customer support should be able to provide the measurement from the front main bow (junction of front dome and main roof panel) to the rear for the placement of the Air Conditioner opening.
If you are planning this as a do-it-yourself project or if someone is installing the unit for you who is not familiar with Airstream, it is a good idea to cut bracing material to maintain the proper relationship (distance between) the cieling and roof panels (my installer used what appears to be pressure treated 2" x 4" shaped to fit the opening) - - I was told that this was in part to insure a leak-free installation.
Something else to keep in mind is that Airstream only manufactures condesate drain pans for certain air conditioner makes and models. You can learn about the air conditioners for which drain pans are available from the same sources as the air conditioner opening placement. The function of the condesate drain pan is to keep the condesate from draining on the roof and running down the sides - - the air conditioners on both my Argosy and Airstream do not have the condesate drain pans so drain on the roof and down the side - - it has been a bigger problem on the Argosy (rust streaking on the sides) than it has been on my Overlander where only a little water spotting may be evident from time to time (Walbernizing seems to keep any problems on the Overlander at bay).
Good luck with your research!