Glyn, we have a replacement Coleman AC on our 1968 Tradewind the PO had
installed professionally. I say professionally -- the interior drain line
was not used and it may not be possible to use it without the pan that goes
underneath the AC. I have made an extensive inquiry about a drain pan for
the Coleman AC and there never was one supplied as original equipment. There
is a company in Florida that makes a universal drain pan for RV air
conditioners. It does not utilize the Airstream interior drain line but it
might be modified to do so with some ingenuity and effort. Alternatively, it
can be drained as designed using a length of PVC pipe along the roof and
down the refrigerator air vent and under the trailer. I've had three
Airstreams since 1972 all with a roof mounted AC installed in the center
vent. I think the concerns about the appearance of the trailer and it's
aerodynamics and stability with a roof AC are groundless. The factory must
have thought it was a satisfactory if not the best location since that's how
it was done. Functionality is a component of beauty in my way of thinking.
Jim Greene
' 68 Tradewind
WBCCI #1148, VAC, WDCU