A big right of passage when DIY’ing a van is the roof fan installation. There’s nothing like cutting a gaping hole in a brand new van. No pressure! 🙂 I highly recommend you pick up a decent metal jigsaw blade. I believe the one I used was 25 teeth per inch and it cut the sheet metal like butter even with an old jigsaw. I also recommend watching as many YouTube videos as you can stomach on this as there’s a lot of good ideas (and what not to do) out there, they’re just spread out. We decided to install the fan above the bed to maximize the room we will have for solar panels in front of the fan. The fan’s cover encroaches rearward so if you mount it in the front of your van’s roof, you lose a bit more roof space. Between the roof fan and our unobtainium window vents we hope to get some decent ventilation.
The next step was extremely hard. It wasn’t a very warm day and we now needed to put 3 1/8" beads of 3M window weld on the bottom of the Hein adapter. It almost killed us! That stuff is extremely viscous and it took everything to squeeze out the 3 beads. Do this on a warm day or have a way to warm the window weld up if you can. Once we had the window weld on the adapter we pressed it into place and left it over night to set. Since rain was in the forecast we put an umbrella over the hole with weight on the handle to keep it in place.
The next morning we put the fan base plate on top of the adapter plate and used machine screws of varying lengths to attach it to the metal roof. You have to be careful on the back and front edges of the fan as they sit above roof beams. So when you screw into these areas there are 2 layers of metal and you only want to pierce one. Different length screws let you do this. Once it was all screwed down we covered it all up with some Eternabond tape. We have used it on previous projects and it seals extremely well and doesn’t degrade like self levelling dicor. Once we had dropped the main fan unit onto it’s base plate and attached it with the 4 provided screws we jury rigged a couple of wires from the CCP and a grounding point and fired the fan up. Success!!