[Wiretap]

Going to install Maxxair. I obtained a pair of PM roof channel adapter plates off ebay. They sandwich the roof skin and accept the fan mounting screws.
I notice that many of the installs use wooden support framing attached to the stringers. Are these recommended for the Maxxaire or is the roof skin and interior trim collar screwed to 1/4" plywood headliner enough to provide a secure mounting.

 

[keeponvaning]

I'd go with a wooden frame inside. The steel is pretty thin and it makes it a lot easier to trim out. I did it without a frame and then went right back and made a frame because it was just more solid, easier and better!

 

[GaryBIS]

Hi,
I used a wood frame -- its seemed kind of flimsy without it.
The frame also gives you a place to anchor the ceiling panel to around the fan opening.

Gary

 

[RDinNHandAZ]

The 1/2 inch ply would be enough to stiffen the roof tin but you should look to see what the minimum depth the fan is meant to pass through. It may be 1" or a bit more. My Fantastic Vent needed about 1-1/4 inches so I made a surround for it that thick tapered at its edges to 1" as that was going to be the ceiling thickness. That let me attach the vent into it so the strength and the interior finish was essentially done except for a layer or headliner fabric. The taper hardly shows:

 

[Konaguy]

I installed a Maxx Fan last summer without any framing inside. I custom made some plastic filler strips for the ribs outside out of a plastic cutting board. I did put some extra screws into the top to hold it down and secure the filler strips. No issues at all. I used butyl tape to seal. No leaks or lifting. I am going frame around it now on the inside of the van in order to put ceiling panels in.

 

[MsNomer]

"I am going frame around it now on the inside of the van in order to put ceiling panels in."

This is the kicker. If you put insulation and/or ceiling on the inside, you are going to need that filler surround anyway. It's easiest to install it when installing the fan.

 

[Mr A/C]

If you have an interest in installing a custom designed a/c system that ties intothe factory system I can help.

Regards
Mr A/C