How to Install a Maxxfan Roof Vent on a DIY Van Conversion

How to Install a Maxxfan Roof Vent on a DIY Van Conversion

Maxxair Fan Installation
Photo of author

Installing a Maxxair Maxxfan Deluxe roof vent on a DIY camper van conversion helps control interior temperature, relative humidity (condensation and moisture), indoor air quality, and creates air movement. It’s typically one of the first modifications performed on the van, so it’s super intimidating… but you are not alone: it’s a rite of passage for all DIYers, and we still have yet to hear about someone who messed it up. With proper planning and extra precautions, you’ll get it right, learn from it, and boost your confidence. Below, we fully documented the installation of our Maxxfan in our Ford Transit; hope that guides you in the right direction!

Disclosure: This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc.) we will receive a commission fee. The price you pay remains the same, affiliate link or not.


Time Spent


Total Cost

$ 0 USD


Maxxfan Deluxe15100K (White lid, manual opening) Amazon
6200K (Smoke lid, manual opening)Amazon
7000K (White lid, auto opening)Amazon
7500K (Smoke lid, auto opening)Amazon
Roof Vent Adapter1Transit Low RoofeBay
Transit Mid/High RoofeBay
Sprinter NCV3 Low/High RoofeBay
Others (Sprinter T1N, Nissan NV, E Series, Transit Connect, etc.)eBay
Roof Vent Backing Frame1This goes inside the vaneBay
Dicor Self-Leveling Lap Sealant2WhiteAmazon
3M Window-Weld1Fast UrethaneAmazon
Butyl Tape1 Amazon
Machine Screws16#10-24 thread, length TBD*, Stainless Steel, Round HeadAmazon
Nuts16#10-24, Stainless SteelAmazon
Washers16#10, Stainless SteelAmazon
Clear Coat1  

*The length of the machine screws required vary with installation (van model, interior adapter or not, etc.), so we can’t possibly make a specific recommendation. It is your responsibility to find out! You can plan ahead by summing up the thickness of all the components (buy various lengths just in case), or you can find out during the installation by actually measuring the total stackup. Any local hardware store will have screws.  🙂


Item Description Quantity Link
Caulking Gun For 10 oz cartridge 1 Amazon
Jig Saw DEWALT Cordless Lithium-ion 20V 1 Amazon
Blades for Jig Saw Thin Metal Cutting, 5-Pack 1 Amazon
Metal File To break the sharp edges 1 Amazon
Sandpaper Surface preparation before touch-up 1 Amazon
C-Clamp To hold everything in place when drilling 4 Amazon
Duct Tape   Amazon
Painter Tape    1 Amazon
Isopropyl Alcohol    1  


Good To Know

Maxxfan Models

Rain Shield

All the DELUXE models are designed with an integrated rain shield, meaning that the lid can remain open at all times, even when it rains. Neat! That’s a major advantage over the competitors… Indeed, you’ll want good ventilation during rain episodes.


The 5301K & 6401K Maxxfan models feature only 4 speeds, cannot be run as intake, and doesn’t have an “automatic” mode. For these reasons (but mostly because there’s only 4 speeds), we wouldn’t really recommend it.

Electric Lid Opening & Remote

The 7000K & 7500K Maxxfan models feature an electric lid opening & remote (as opposed to the model 5100K & 6200K, which must be opened manually, and there’s no remote). We personally have the manual lid opening and we’re perfectly fine with it. We chose it because we worried that the electric opening might have a hard time in snow/ice. We also don’t have the remote, and we don’t mind that either because we’re always an arms-length distance from the fan anyway!

White VS Smoke Lid

At last, you have the choice between a white lid or a smoke (grey) lid… that depends mostly on personal taste and your van’s color!


Maxxfan Power Consumption


Do not use a grinder!

Using a grinder to cut the fan’s hole is pretty bad ass. But all these cool sparks are actually metal chips going all over the place, and each one of them is a potential ignition point for rust! These tiny chips stick to the van and it’s just impossible to clean them afterward, so DO NOT USE A GRINDER.

grinder metal chips rust
So cool. So manly. So wrong.

Where to install: Back or Front?


Most people choose to install their fan in the back of the van as it creates an air flow that runs through the entire van: air enters by the front door windows and exits by the fan in the back.

We think it’s the ideal location, except if you’re in a similar situation as us (keep reading “FRONT”!).


Because we live full time in our van during skiing season, cooking with the doors open is not an option. Therefore, we installed our roof fan straight above the stove/oven ( That way, the cooking smoke & smell are evacuated immediately.

But there is a drawback: air in the back of the van is not well recycled. To compensate, we should have added a window in the back (


We see many people with 2 fans on their van: one in the front, one in the back. Typically, one fan acts as the intake (OFF) and the other fan acts as the exhaust (ON).

People with this setup are really happy about it as it creates excellent ventilation. It’s cheaper (and easier) to install a second fan than a window, but the drawback is that it uses more real estate on the roof. If you planned on adding a patio on your roof, that might be an issue.

Adding framing strips or not?

You can order the Roof Vent Adapter with, or without, framing strips (see eBay link under “Material” section above). The framing strips provide additional support to the roof and are recommended if the fan is installed at a location where the beams are more than 18 inches apart.

In our case, we installed the Maxxfan in the front of the van where the beams are close together, so we didn’t need the framing strips. 



Roof Rack

If you’re in the market for a roof rack, check out Flatline Van Co “Low Pro” roof rack: it has a modular design, so the cross bars can be shuffled around to fit your custom roof layout (Maxxfan, solar panels, A/C, etc.):

FlatLine Van Co "Low Pro" Roof Rack
  • Modular: you can shuffle the cross bars around to fit your custom roof layout (e.g. solar panels/roof fan/etc);
  • Low profile: a bit more stealth and aerodynamic than the tubular aluminum “overland-style” roof rack;
  • Easy installation: it’s attached to the van’s roof with the factory mount points (no-drill!), and because they are modular they ship flat packed in a box and they are easier to install (less bulky);
  • Easy to install gear and accessories: the cross bars are 80/20 aluminum extrusions, so you can get creative and attach pretty much anything in any possible way: solar panels, decking, awning (Fiamma F45S direct-mount, no drill), light bar, etc.

For more info (features, specifications, installation, ordering, etc.) click below:

And now let's get to work!

1- Install the painter's tape and mark the fan cutout.

To mark the fan cutout, we used the inside of the roof vent adapter.

2- Practice makes perfect…

We “simulated” 2 holes and a straight line to practice drilling & cutting on the panel we were getting rid of. It’s a good thing we did it! We learned that it’s better to make the corner holes a bit outside of the cutting line (the fan flange allows some over cut) AND that a storm of hot-burning metal chips will blow on your face and into your hair. WEAR PROTECTIVE GLASSES AND A SEXY BANDANA ON YOUR HEAD. You’ve been warned.

3- Lion's face: you own the tools, the tools don't own you!

Or: we're scared, but let's pretend we're not.

4- Drill a hole at each corner, large enough to let the jigsaw blade pass through.

5- Cut each side, then apply duct tape to prevent the panel from falling during the last cut.

6- Break the sharp edges with a metal file and smooth the edges with a fine sandpaper.

7- Install the roof fan adapter and the fan flange and drill all holes.

We used four C-Clamps to ensure nothing moves during the process.

8- Surface preparation.

- Remove the roof fan adapter and the flange.

- Break the holes sharp edges and smooth with a sanding paper.

- Clean the surfaces to be touched-up with isopropyl alcohol.

9- Apply Primer, Paint & Clearcoat on all the cuts and holes.

This is an important step to avoid corrosion in the future. Indeed, paint plays a much bigger role than just adding color: paint protects metal from rusting. So take note: adding primer + paint + clearcoat should be performed ANY TIME you make a cut or hole in your van. Get used to it!

TIP: All-in-one products don't work well; so primer + paint + clearcoat = 3 different products. Go to an Auto Parts Shop and give them your color code (it's on the driver's side door sticker), make, model & year, and they'll prepare paint that matches perfectly the color of your van. Spray paint can work well because you can spray what you need in a small plastic container and re-use the rest later (after use, turn the can upside down and spray for a few seconds; this will clear the tube and prevent clogging).

10- Clean the fan flange with isopropyl alcohol.

11- Clean the van's metal with isopropyl alcohol.

12- Apply butyl tape on the fan flange (on the surface that will be mating with the fan adapter).

13- Apply 3M Window-Weld on the roof fan adapter and the backing frame (on the surfaces that will be mating with the van).

14- Install the roof fan adapter, the fan flange, the backing frame, and the hardware.

15- Apply Dicor self-leveling sealant around the periphery of the flange.

While she's working, make yourself useful and start cleaning the work area. Or don't and just be a nuisance by making duck faces for no good reason.

16- Install the Maxxfan unit through the fan flange and fasten using the 4 provided screws.

17- Look at our fan.

Just look at it.

18- Final Test.

We tested our Maxxfan using the wires from an adjacent light that we removed. (Note: we blew a fuse doing the same thing afterward: no surprise, the 7.5 amp interior lightning fuse located at position F32 is not designed to withstand the load of an additional fan… no big deal, the fuse was replaced and the light is back!) It works!

19- Have a pint of fresh Homebrewed Session I.P.A.

Well deserved!

On Second Thought...

We've been using our Maxxfan since 2016, and it does exactly what it's supposed to: it's powerful, doesn't draw too much power, and being able to run it when it rains is SO IMPORTANT. If we had to start over, we would definitely install the Maxxfan again!

Maxxfan Review

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About us



Hello! We’re Isabelle and Antoine 🙂 In 2017, we sold our house (and everything in it), quit our engineering careers, and moved into our self-built campervan. Every day is an opportunity for a new adventure... We’re chasing our dreams, and hopefully it inspires others to do the same!

Heads Up: Exclusive Deals!

Thanks to all of you, we managed to negociate group discount on these. Strength in numbers!

83 thoughts on “How to Install a Maxxfan Roof Vent on a DIY Van Conversion”

  1. I have re-read this a few times and idk if I am missing it somehow, but was the backing adapter pre drilled? The instructions mention the roof adapter and flange during pre drilling, but not the backing.

    Thank you in advance!

  2. Total Cost: 350.00? That’s ridiculous. Our Maxxfan cost $276+ Tax alone. Add to that the Adapter that came with Butyl Tape @ $75, Dicore Sealant @ $12, 3M Window Weld, $17.99 and you have $411.00 That is todays Prices as I bought all this stuff on Amazon and Ebay today. Maybe the prices have gone up a bit? Just goes to show, you are not updating this and reaffirms my decision not to buy your plans, and buy from your links. The more time that goes by, the more it gets out of date…Suggestion. Once a month, take one section of your website, and update it. twelve sections could be updated in one year. I know it’s a lot of work…but C’mon…you can do it…you have a good thing going here.

    • Using the links from our article:
      Maxxfan 5100K: $222.24
      Vent adapter: $68.88
      Dicor lap sealant: $10.29
      Butyl tape: $10.72
      Window weld: $23.64
      TOTAL: $335.77
      (you’ll hit $350 after you buy the hardware)

      Keep in mind that Amazon prices vary with geolocation (USA vs Canada, etc.) and through time. That’s why we don’t price the items individually. The total price we mark is what it should cost for most people.


    • When considering the insane number of hours they have put into this site, putting a few dollars towards supporting their work & getting some nice plans was some of the easiest money I’ve ever spent… great site <3

  3. how long did you wait in between applying the window weld and clamping the adapter before you finished putting the screws in and then the dicor?

    it is only 5-15 degrees C over the weekend, so i would like to be able to install the adapter and flange with the 3m window weld and decor lap sealant in the same day. the instructions that came with the adapter say to wait overnight

  4. We’re getting ready to install our MaxxFan but can’t find Dicor anywhere nearby and it’s going to take several weeks to get it, can we use FlexSeal instead? Thanks!

  5. Ugh. So we spent all day on this and dropped the fan in and the screw holes on the flange are too low to match up with the holes on the fan. Help!

  6. Hello!! Your site has been a godsend for navigating the complexity of the van project:) I just went to buy the backing frame with the affiliate link you provide, but it gives 2 options for thickness: 1/2” and 3/4” – Which do you recommend for this installation? (It’s for my HR extended Transit, but hopefully this will help others too!! )

    On a side note, I’m curious if you have a take on the two fans vs one fan plus small window deliberation? I’ve been in vans with two Max fans on a hot day and it feels AMAZING. But, your post on passive intake made me wonder if it was the double fan power or if one fan plus small window would do the same thing.

    Take care and thanks so much for the site that is a saving grace for this DIY-er!!!!! 🙂

  7. Hey! Thanks so much for the build journal, this has been such a help.”

    I loved the idea of the center-cut shears, so I bought the WEN shears you linked to. After using it I have to say I disagree with the recommendation for two reasons:

    1. Shears cannot turn while cutting. The design of the shear makes it impossible to turn a corner like you need for a window or fan opening. At the vary least, the recommended product cannot be used to cut a corner. This means you have to use a jigsaw for the corners, which leads me to reason 2
    2. The curl of material leftover interferes with the jigsaw you’ll have to use for corners. It’s a minor inconvenience (trim off the curl with the shear and bend it out of the way), but it’s noticeable.

    I’m glad I tried the shears, and the way cut metal in a straight line is second to none. But they’re not a good cutting tool for this application.

  8. Could you give more specifics on the wiring of the fan. I am putting mine forward in about the same spot as I live and work on Glacier National Park and an open door in winter is not an option. I have a light in the same vicinity as you do. Did you just wire it in to that light or? The only issue I am trying to resolve is my final wiring.

  9. Just finished our fan install today! Your guide was a huuuge help and set us up for success, thank you.
    Happy travels!

  10. I thought I would be fancy and buy the shears instead of using a jig saw. I ran into a issue immediately. While they cut very smooth and do not produce metal shavings, they require a much larger entry hole and more importantly do not turn corners at all. This makes them very difficult to use for a window install with rounded corners. They will also not cut through any internal bracing, requiring a jig saw anyway. After a few telling test cuts I gave up and did everything with the saw. With a well placed trash bag you can avoid spraying metal filings everywhere. Don’t buy the shears they are not worth it.

    • I did the same, thought I could be high-tech and avoid the scalding metal shavings in my eyes but no, the shears were fun to play with but useless to this project.

      • Just cut the hole out from the top externally. No need to worry about being showered in steel fragments then.

      • We will be getting 2021 Ford mid roof in a week or so. Do we have the 14″ space? Also, do you have a link that gives info on Ford modified wiring, dual alternators, and the up fitters switches how to incorporate into the wiring. Thanks

  11. Could you confirm what length of machine screws you used? It says TBD above. I want to order via your link but IDK if it leads to the right size. 1 inch seems to small. Thanks!

    • +1 trying to figure this out and also why all the screws extended beyond the skin…I was just going to penetrate the four corners…less holes to chase if leaks ever arise.

      • Hi. I just updated the article with this note:
        *The length of the machine screws required vary with installation (van model, interior adapter or not, etc.), so we can’t possibly make a specific recommendation. It is your responsibility to find out! You can plan ahead by summing up the thickness of all the components (buy various lengths just in case), or you can find out during the installation by actually measuring the total stackup. Any local hardware store will have screws.  🙂


  12. Would you address the pros and cons of the Maxxair Fan vs a rooftop AC unit? Could an AC unit replace the maxxfan? Seems if the AC unit could do what the maxxfan does AND be an AC when needed, it would be a bonus, especially when traveling is southern climates.

    • I’m no AC expert, but I believe that AC units cannot act as a fan (exchange air between inside/outside), and that’s why RV have BOTH fans and AC. Fans are still required to exhaust moisture and to evacuate “polluted” air from inside.

  13. Thanks for this detailed post (and entire website!) I’m curious why are the roof vent adapter and backing frames absolutely necessary ? I looks like it ads a bit of height to the fan installation. I though the butyl tape would fill the groves of the roof. Does maxx fan not come with everything necessary to be installed directly on the metal ? (I installed fantastic in my old van and it came with an adapter sleeve thingy) Thanks for your answer !

    • You can fill the outside groove with butyl tape, but the adapter makes it much easier and reduce the risk of leaks in my opinion. On the interior side (inside the van), the surface is relatively flat so you can buy the backing frame OR you can make your own backing frame with wood or similar…

      Good luck!

  14. I have seen on other websites that the fan needs to be wired to the 12V aux source (cigarette lighter) in the van. But on your website you connected the fan to the wire for the lights and upsizing the fuse. What are the drawbacks for this connection? Have you had any issues?

  15. I’m gonna mount max fan soon and wanted to know if having the backing adapter is needed. Was thinking of not adding one and if I do was gonna use flat aluminum

  16. Hi
    Question regarding the #10 screws. I appreciate going with Stainless and using locking nuts and washers. My question is regarding #10s. My Maxxfan came with #8s. Did you size up for a reason or was your fan’s flange cut with #10 sized holes?


    • totally well asked. that is the step i am at now. are the bolts necessary? the screws do not go through all of the backing. Very interesting that they did not come with bolts. hmmm. I am not sure what to do. I bought their bolts too. just thinking out loud

      • I am as this point too and have the same issue. I am assuming the #10s were to ensure girth to attach both backings. I missed this part and didn’t realize we don’t have the correct screws. I guess I will be heading to the hardware store later today!

  17. Hey! thank you guys for all the good information!
    Question about wiring the fan: the wire on the fan is 14 gauge and for my run i am going to use 12 gauge.
    What is the best way to make this connection? Use 14 gauge quick disconnects for all connections and just stuff the 12 gauge wire in there?
    thanks for your advice

  18. Hi there, thanks again for sharing with everyone your knowledge, I am not completely sure if I need a Roof Vent Adapter or not? I am in europe and the website that I am ordering from told me that everything is included in the maxxfan deluxe. have you ever seen a kit where it was included?
    Could you please explain the need of an adapter? Thanks


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