Carving a space for a roof vent

I bought my first van and don’t want to do any of the windows. It’s a Dodge Promaster high roof. I am on a really tight budget but the most important thing is the roof vent. Anyone know of any resources, or where to start?

Put it as far away from opening windows or vents as possible. That way you’ll get good air flow throughout the van. Most vents use a 14x14" opening. When you cut the hole, be sure it’s not through any structural body ribs or you might compromise the body. Should be plain flat sheetmetal. Other than that, follow the instructions that come with it and power it from a house battery, not the starting battery.

On the promaster, there is a area near the front clearly designed for mounting an A/C or vent fan. The standard is 14x14" and there is a ring of flat metal that, remarkably, just fits.

The Maxxair I installed had at least 1/2" of slop around the mount flange - i.e. don’t cut the opening exactly 14x14 or you will be filing it out to make the mount fit. Maybe 14-1/6" square… I sealed my mount ring to the roof with a layer of butyl tape running the screws though the roof and into a block of wood below (which, incidentally was used to attach the ceiling panels to). Tighten the screws enough to make the tape squish a little an no issue with leaks and no “lap sealant” goop every where.

Many vans mount the vent near the back, but I chose the front to
a) get it as far away from the bed (noise) and
b) closer to the galley (cooking fumes) and
c) the convenient flat section of roof: no adapter or piles of sealant needed.

With rear opening windows it makes for fantastic venting in warm climates. If you don’t have operable windows, FarOutRide put in a 4" vent in the floor at the rear and used a drier hose to direct the cool air where it was needed. A clever solution, IMO.