I want to add an AC to my 4ft sw Featherlite.  The directions for installation of the unit, state that a frame needs to be added to the 14" square opening for support.  Does anyone have any suggestions  what to use?  (I have friends who will do the wiring and installation, but we don't know how to frame it in).

I'm also intrigued with the idea of a heat pump AC, as I've heard that the heat strips don't work very well.  Any comments on that?

If you are not going to finish the interior, go to your nearest Featherlite dealer and buy the additional factory aluminum bracing. They can be welded into place. If you intend to finish the interior, you can add hardwood bracing that will become stringer supports for the ceiling.

gard