Installation of MaxxFan fan / vent in rear of ProMaster Camper Van
(The forum tipped the images on their sides, despite having already rotated them on my computer. Since this is a bit annoying to look at, I've also included pictures in Imgur album - link at bottom of post)
I know this thread exists already, but Google isn't picking it up well because of the title, I think. So, a couple pictures and pieces of advice from my vent install.
1. Pick your fan: I went with the MaxxAir Delux 7500k
, but all fans are pretty much the same I gather.
2. Pick your spot: I went with a mid-rear position, rather than placing it in the apparent sunroof location right behind the drivers cabin. I wanted to get the fan above the bed (my van is becoming a camper), to pull air through the vehicle. If the cargo area has 4 roof "sections", this would be the second one from the back. The obvious challenge with this location is the ribbed roof, which really wasn't as bad to deal with as I was expecting.
3. Make a "template" for the hole you are about to slice: In retrospect, I would have spent a lot LESS time on this step. My recommendation is to make a 14ish inch square out of some cardboard. I say 14ish inch square, because if you come out slightly crooked or off 1/8th of an inch, its no problem because of how I actually marked and cut out the hole - see below.
4. Side to side placement on the roof: I went dead center. It might be ever so slightly easier if you offset it by one roof rib so your cuts are ending up on TOP of a rib, rather than on the angled space between a high and low section of the roof ribs.
5. Forward / back placement. As I mentioned, I went with the second roof section from the rear, in the middle of the roof braces. However, turning this general position into reality while sitting on the roof was a chore. So, I brought the fan housing into the van, held it up on the ceiling exactly where I wanted it to be and marked dead center of that square. With that spot marked, I drilled a single hole UP through the ceiling so I could find the same spot on the roof. This let me place the housing in the exact same spot on TOP of the roof.
6. Drawing a square on the roof, so you know where to cut: This was easier said than done. I tried and tried with the cardboard template (and one of those
so I had more than once chance). Good thing I used a rub-away marker, since the template proved about useless. (Template was useful to visualizing approximately where the vent would go, but unhelpful in actually drawing lines on the roof.) It was REALLY hard to convince myself I was exactly in line with the roof and the fan would end up straight. I would never forgive myself for cutting a crooked hole in my roof..
My solution was to take a piece of strong cord or string and tie it between the roof rack mounting nubbins, which did a great job of creating a perfectly straight line across the roof of the van, only 7 or so inches ahead of where the fan would end up. Once that straight string-line was in place, it was easy to measure the from the string line back to where the forward most edge of my hole should be (this measurement is figured out by using the center hole I drilled in step 5, which was the middle of exactly where I wanted the fan). I measured this same distance on every roof "ridge" and marked them (this time with Sharpie!). Once I connected these dots, I had my forward line. From this straight, accurately placed line, I could build the rest of my 14" by 14" square with a lot of measuring and re-measuring.
guide string and tape outline.jpg
7. Prep inside: My wife had the super idea of loosely taping a big piece of plastic (I sliced open the protective plastic bag the fan was shipped in) to the ceiling all around where the hole would be. We taped it up good and it did a GREAT job of catching all those super sharp metal filings that the saber saw produced. Once the hole for the van is cut, and you've cleaned up the roof and edges, you just carefully remove the plastic and throw the whole shrapnel filled pouch in the dumpster.
filing catch with hole.jpg
8. Prep the roof: Hard to explain, but check out the picture. I put masking tape down around the lines for a couple reasons. First, I wanted to protect the roof from the skids on the jigsaw, and second, the tape gave the skits something to rest on for the cuts going across the roof ribs (this means you have to make those cross-rib cuts first, or you'll slice through your tape).
9. Practice cutting: I did a little slicing around in the middle of the square to get used to the feeling of the saw in metal. I've never cut anything metal before, ever, so didn't know what to expect.
10. Cut! Drill some holes on the INSIDE of your lines. These can be close to the corners, but don't need to be - somewhere along the line is fine. Either way, you'll need to go back and clean up the corners. As I mentioned above, I cut the cross-rib lines first. As I finished each cut I used some gorilla tape to secure the inner square of material to the still solid roof to prevent vibration.
11. Clean up a bit: Careful wiping those tiny razor sharp filings off the roof - if you aren't, they will scratch your roof. I ended up using a handheld vacuum. I also used a file to smooth off the edges of the hole, since there were burrs all over. Before removing the plastic bag taped up in step 7, I also placed the fan frame in place and drilled small pilot holes for the screws, since those create filings too.
12. Apply some primer: metal primer on all the new cut edges, as well as the pilot screw holes. Cheap, quick - necessary? No idea, but seems like a good idea.
13. While that primer dried I prepped the fan mount by placing "butyl" tape around the edge that would contact the roof. I used 2 overlapping layers, making sure to cover all the tape joints. Pretty simple. I also prepped the low points between the roof ribs by building up the low points (see Dawn's picture here: https://www.promasterforum.com/forum/...t=15729&page=2
14. Screw it: As long as you keep track of what screws in the kit go where, this is pretty straightforward, with the exception of getting the screws to hit the pilot holes through all that butyl tape. Just took some fuss, but no big deal. I started the screws with a drill, but finished them by hand. I guess they're tight enough? I could have cranked down on them more probably - not sure how to say when the housing is tight enough.
15. Mount the fan: This was a little challenging - the new MaxxAir fans have a gasket around the fan housing, which probably does a great job of keeping water out, but also made screwing the fan onto the housing a challenge. Right amount of pressure in the right place, and some patience, did the trick.
16. Sealant: I let that butyl tape squish out overnight and throughout the next day. Then I used a putty knife to cut away the excess and applied some silicone sealant around the perimeter of the housing and on top of each screw head.
I also ran some wire to the battery with some conduit, but this will change when I add the second battery in the rear of the van. Tip: before insulating or paneling, run some conduit through the empty spots in the van frame for easy cable running in the future. Also, a coat hanger made a great (chimpanzee simple) tool to run the wire under the plastic mat and under the drivers seat to the battery housing. Undo the hanger, bend one end into tight "U", stick one end from the battery housing, under the mat toward the cargo area until it pops out from under the mat. Then tape the wire to the end of the hanger and just pull it back to the battery.
wiring and conduit.jpg
Imgur album here: