How-To Install A Roof Fan On Your Van
Tricia here, writing my first post! Over the weekend we tackled the daunting task of permanently modifying Gidget by installing a roof fan. Neither of us have had the pleasure of cutting a huge hole in a vehicle, so it was a little nerve-wracking.
When planning our van build we decided not to install a rooftop air conditioning unit. They tend to remove any notions of stealth, are loud, and need a lot of power to operate. But we also want some level of comfort so we settled on a roof fan. After significant research we discovered there is only 2 serious manufactures: Fan-Tastic and MaxxAir. We went with the MaxxAir MAXXFAN Deluxe 7000K fan because the lid can be open when its raining and when driving.
- MaxxAir MAXXFAN Deluxe 7000K – $289.34
- Roof Adapter – $44 (or $88 for both the top and bottom adapters)
- Butyl seal tape – $11.04
- Eternabond tape – $19.07
- 3M 4200 Adhesive – $25.08
- Zinc coated wood screws (#10 7/8″ and #10 3/4″) and washers (#10) – ~$8
- Painter’s tape
- Duct tape
- Isopropyl alcohol
- Metal cutting blade
- Caulking gun
- Phillips screwdriver
- Safety glasses
- Shop vacuum
- Metal seam roller
We started Saturday around 1:30 PM and finished before lunch on Sunday. Just in time for the little bit of rain we had on Monday morning. It was around 8 hours of actual work not counting the time for the adhesive to cure.
The first step is to decide where you want to install the fan. We choose the rear of the roof between that last 2 ceiling ribs, 21″ in front of the rear door frame. This spot will be above our future bed and leaves ample room to install solar panels. It also just so happens that the Transit has almost 14″ between the 2 roof ribs.
The Transit roof is thin and dents easily which makes installing a roof fan difficult. The location we chose for the fan is just close enough to lean over from the edge and perform the whole install. Our ladder was just tall enough to lean against the rear of the van. We put a thick blanket between the ladder and the van to protect the surface.
Then we prepared the top of the van by washing it with soap and water, and cleaning it with acetone.
We then taped off the area where the fan was going to go on the inside and outside with cardboard and painters tape. This stops any of the metal filings from cutting and drilling from landing on the paint.
Next we drilled holes in the 4 corners, starting with a small drill bit and ending with the largest drill bit we had. The hole needs to be just large enough to fit the jigsaw blade. While drilling the holes we used a shop vacuum to suck up all the little metal filings. No turning back now…eek!
The next step is to connect the holes with a jigsaw and a metal cutting blade. This is where we ran into some troubles. The jigsaw we owned was not strong enough to hold the blade in place. We tried several times but the blade would just fall out onto the van floor. Luckily our friend happened to be at Home Depot and picked up this gem for us. It worked a thousand times better, and after our brief work stoppage, we were back in business.
While Matt was cutting from the top I was below vacuuming any metal filings coming off. After cutting each side we used duct tape to support it.
After cutting the the hole, use a metal file and sandpaper to smooth out the edges.
Next apply a coat of white paint to the edges to prevent any rust from forming. We did 2 coats and went real heavy on the second coat and let it dry for about an hour.
The Transit roof is curved but most roof fans assume a flat surface. Some Transit owners have used JB Weld and adhesive caulk to flatten the area out. Some have used spacers. We decided to use an adaptor on the top of the roof which turns the curved roof into a flat mating surface for the fan base.
You can also buy an adaptor for the inside of the roof. But it won’t fit in the rear location because the roof ribs are too close together. If installing between the middle ribs or the front ribs the inside adapter will work.
We cleaned the roof and adapter with acetone, and then used 3M 4200 adhesive to attach the adaptor to the roof. 3 beads on all sides seems like a good amount.
After placing the adaptor on the roof, we used 4 clamps to gently hold it down. You don’t need to clamp it down super tight, just enough to make sure there is a good seal. If you clamp it too much you will bend the roof.
By this point, the sun was starting to set, we were tired, and the 3M 4200 adhesive needed time to cure. We covered the van with a cardboard box and plastic tarp just in case it rained overnight, and called it a day.
Sunday morning we started around 8 am to be sure it was finished before the forecasted rain on Monday. The adaptor had over 12 hours to adhere to the 3M 4200 and van roof. We put a little bit of pressure on it and determined it wasn’t going anywhere.
It was now time to install the fan flange to the adapter. The surface was first cleaned with isopropyl alcohol. The fan instructions say not to use acetone and the 3M 4200 instructions say not to use alcohol. So when cleaning anything that touches the 3M 4200 we used acetone and for the fan we used alcohol.
Next we added butyl seal tape to the bottom of the flange. The flange is just wide enough to fit 2 strips of the tape.
The flange was then attached to the adapter using #10 zinc coated wood screws and washers. The thicker side used #10 7/8″ and the thinner side used #10 3/4″. First pre-drill the screw holes. We did not drill into the van roof, just into the adapter. We recommend hand tightening the screws to avoid cracking the plastic fan flange.
We wanted to avoid using screws and just use 3M 4200 to attach the flange to the adapter. But 3M 4200 contains Xylene which according to the fan instructions shouldn’t be used on the plastic. In hindsight, it probably wouldn’t have mattered and we should of done a small test on the plastic to see what would have happened.
After the flange was screwed down any excess butyl tape was removed using a box cutter.
Next Eternabond tape was laid down on the van, adapter, and fan flange. The white Eternabond tape is primarily used as a weather seal to keep water from leaking into the van and secondarily as another adhesive keeping the fan attached to the van. The Eternabond is extremely sticky, so be cautious while installing it, because once it is down, it is pretty impossible to remove.
After you place the tape down use your hand to apply pressure and then follow that up with a metal seam roller.
It was now time to actually place the fan on the roof. This part was easy, guide the wires down through the hole and then place the opened fan on top of the flange. The fan instructions require you to manually open the fan before installation. While Matt was on top of the van, I was down below and used a thin flat head screwdriver to push up the metal clips slightly. Then Matt screwed in the fan with the 4 provided screws.
If you want you can also take of the MaxxFan stickers. They peel right off.
Next was the moment of truth. Would the fan work? We hooked it up using our car jump starter and crossed our fingers.
With a sigh of relief, the vent closed when powered on, like the instructions stated it would. The fan works!
Once we install our house electrical system we will wire up the fan. And once the ceiling is done we can place the interior trim piece to cover the raw edges.
If we did the install over we would have done a better job covering the top of the van to prevent metal filings from landing on the paint. We did a pretty good job with cardboard but it still allowed some filing to work there way under the cardboard. We would have used 3M 4200 to mount the flange to the adapter plate instead of screws. Finally, we would have used lap sealant instead of the Eternabond tape as the end result isn’t as clean looking as it could have been.