Coleman Mach III RV rooftop AC unit install on roof of E-150?

[mboardman]

Anyone mounted something similar? Im wondering specifically if I can avoid using the grille on the inside and mount the unit so it ties in with the existing rear AC ductwork? Im thinking the roof of the van wont hold the 100lb weight, or that the mounting will be unstable because of how thin the roof is. Normal installation looks to be 2x4 thickness in RV roofs, and I dont have that in the van. Id rather not build a bracing box on the inside, for aesthetic reasons. Anyone have better ideas or seen it done before?

Using the van for work, camping every night in between stops, all summer long. So AC is not an option, its absolutely necessary. I need something that can run off campground power each night and Ive located a used mach 3 unit for $200, but no mounting hardware.

 

[r_w]

There is always the small window unit in the back door/window.

 

[landyachtcaptn]

I haven't done one on a van but have done a couple on Airstream and regular campers. I think you will need a frame. Even if it is just a 14" x 14" box around the opening I think you will need something. Ideally your frame would tie into the cross members in the van ceiling. I don't think you can tie into the central duct because your controls will be in the inside trim unit. Also there will be return vents as well as the supplies which you will want to keep separate as much as possible. Also, be mindful of where your condensate comes out unless you get a unit with a pan and a tube that runs through the inside of the van and drips it out on the ground you will be puddling it up on the roof.