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

Maxxair Fan Installation

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

Installing a Maxxair Maxxfan Deluxe roof vent on a DIY camper van conversion helps controlling temperature inside the van, relative humidity (condensation and moisture), indoor air quality and creates air movement. Don’t be intimidated by this task, it is well within the average DIYer’s reach! Let’s do it!







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  • Jigsaw & metal blades (have some spare blades, we broke one in the process)
  • Files
  • Sandpaper
  • Caulking gun
  • Vacuum (metal chips will be all over the place. Get rid of them as soon as possible to avoid scratches)
  • Screwdriver
  • Safety Glasses and hat
  • 4 x C-clamps


Maxxfan Installation, Material
Material for Maxxfan installation


How we installed the Maxxfan roof fan on our van


1- Install painter’s tape and mark the fan cutout

To mark the fan cutout, we used the interior side of Hein’s Ford Transit RV roof vent adapter and it was super easy since the adapter will “locate itself” in the center of the sheet metal panel. Sweet!

Drilling and cutting practice


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 allow 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.

Practice makes perfect for maxxair fan installation


3- Get ready to cut the crap out of your brand new van. And enjoy!

Cut the crap out of your brand new van


4- Drill 4 holes at each corner, large enough to let the jigsaw blade through

Maxxair Fan Installation,, Drill 4 holes


5- Cut each side, then apply duct tape to retain the panel from falling at the last cut

Maxxair Fan Installation, cut each side


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

Maxxair Fan Installation, Break Sharp Edge


7- Install Hein’s adapters (interior and exterior) and the fan flange and drill all holes

We used 4 c-clamps to ensure nothing moves during the process.

Maxxair Fan Installation drill holes

TIP: Slightly oversize all holes on the interior adapter for easier re-assembly. Do it.


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


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


10- Apply Primer, Paint & Clearcoat on fan cutout and drilled holes

This is an important step to avoid corrosion in the future.

TIP: You can have your exact van color prepared for you in almost any auto-parts store. Just give them your color-code (printed on the driver’s door frame), year of production and make.

Maxxair Fan Installation,, primer

Maxxair Fan Installation, paint


11- Clean fan flange with isopropyl alcohol


12- Clean van sheet metal with isopropyl alcohol


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


14- Apply GE Sillicone II on Hein’s fan adapters surfaces that will be mating with the van

This is to prevent moisture retention and corrosion.


15- Assemble Hein’s adapters and fan flange all together with the fastening hardware

We used washers both on the interior and on the exterior surfaces.

We did not oversize the holes on the interior fan adapter. With the butyl tape and sealant, it was difficult to re-assemble…

Maxxair Fan Installation, install screws


16- Apply Dicor self-leveling sealant around the periphery of the flange

We ensured to cover the van panel, the fan adapter and the fan flange. We also covered all the screws.

Maxxair Fan Installation, apply sealant


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

Maxxair Fan Installation, Install Fan Unit


18- Look at our fan

Just look at it.

Maxxair Fan Installation, final
We have a Maxxfan!


19- 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 interior lightning fuse of 7.5 amp 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!

Maxxair Fan Installation, testing the fan


20- Have a pint of fresh Session I.P.A.

We deserved it!

Maxxair Fan Installation, reward




On Second Thought…

We’ve been using the Maxxfan since June 2016, here’s our review:

Maxxair Maxxfan Deluxe Roof Fan Review






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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. We’ve been on the road since then and every day is an opportunity for a new adventure; we’re chasing our dreams and hopefully it inspires others to do the same!




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

  1. Hi! We actually have a Ford e350, but we’ve adapted most of your instructions to work with our van! It’s been great. We’re about to install our Maxxair fan, but we’ve noticed that some other websites/blogs don’t use an adapter at all…but maybe they are making a huge mistake? Have you heard of anyone installing a Maxxair fan without an adapter and it being successful?

    • An adapter is not mandatory, you could probably use layers of sealant instead (butyl tape?) to create a flat surface. But the adapter makes the job MUCH easier and ensure a proper seal (since it fits perfectly with the roof’s corrugations).

      We highly recommend it, but it’s you call in the end 🙂

  2. On the maxxair fan instructions it specifically says not to use Acetone on the plastic. Step 11 in your guide says to clean the fan flange with Acetone.

  3. Heyo! Thanks for the great guide! We just did our install today, went super smooth. We can confirm that the interior adapter is not needed and without it we went with 1.5in bolts. We did add neoprene washers on the interior with the metal washers.

    Someone else mentioned having a hard time finding 3/16in bolts, we did too, might be a regional availability thing. Anyways we went with 1/4in bolts and it was fine.

    • Re: 3/16: SS 10-32 machine screws work perfectly, requires only very minimal enlargement of the holes in the flange (13/64 bit). Nylon locking nuts are a good addition for this application (resist vibration). Also, re: easing reassembly: when you glue the adapter +/- internal adapter or framing strips back onto the roof/ceiling, place screws through the holes to self-locate the parts (but remove after clamping to not seal your screws in :)).

    • We installed two pieces (exterior and interior), but I’m not sure if they still sell the interior piece as it’s not necessary (it’s pretty flat in there). Don’t worry about the interior piece.


      • Maybe I just grossly overlooked this, but I can’t find a nice order of operations you did the work in.

        It seems like the fan was one of the first over all steps on the van? What order did you do solar, wiring, insulation and the fan in?

        Thanks again for your great guides, they will be my main resource on the sprinter I just purchased!

  4. So I just saw a nifty life hack online the other day but I think you can test the electric fan and other electric items like that with the battery from your cordless drill you just have to figure out which part is the positive and negative and go from there and I believe it will work. Let me know if you think different. Great stuff nd I’ll be using your info on my build! Appreciate everything!

  5. Notice you show an internal and external fan supports the link you provide only shows an external support, did you buy two or is there a design change? Thanks

  6. Now that you’ve had some time to real life test the fan, how do you like it? Any problems with rain or snow getting in?

  7. Hi Isabelle and Antoine, Amazing journal of your build. I own a mobile bike shop called Cowbell and I service bikes inside the Ford Transit mid/mid van. I’m going to install a roof fan and I’m wondering how to wire it for power. I use a GoalZero Yeti 1250 for interior lights,… Is it possible to wire the fan to the Yeti? Will I have to get a deep cycle battery and an inverter? I’m hesitant to wire it to the battery under the drivers seat as this ones has died three times in three years. Thanks.

    • Hi Todd, it’s a cool business you got there 🙂

      The fan is 12V, so you must NOT use an inverter. You can connect it directly to your Yeti, make sure to use the 12V output, not the 120V. I’m not too familiar with the Yeti so I cannot help with the connection itself (i don’t know what type of connector)… but what I know is that the fan only require to connect a positive wire and a negative wire. Also, you should protect your wire with an in-line fuse (you don’t need a big fuse block for such a simple installation). See our Electrical Design article for more info about that:

      Good luck!

  8. About to instal this and gathering my supplies- do you happen to remember having a hard time finding 3/16 bolts? I found carriage bolts with the smooth rounded top in the correct sixes online, but though the smooth top might be hard to manipulate. Would appreciate any insight you have. Thank you

  9. I just did this project and followed these instructions, some tips for anyone trying:

    – Widening the holes should’ve been done. Don’t be like me and ignore that tip only to be stuck with goopy silicone all over, struggling to get the fasteners in and unable to go back.
    – 2 inches seemed too long for me, but better over than under.
    – Definitely jigsaw from on top of the roof, use a (new!) fine-toothed jigsaw blade meant for metal and set the jigsaw to a fast speed.
    – When you jigsaw cut from the roof, tape a tarp loosely over the place you’ll be cutting to catch the metal shavings, they would’ve been really hard to clean afterwards and likely to mess up the interior paint.
    – Don’t use too much silicone if any. I don’t know if it’s necessary with the lap sealant and it offset my top enough that I had a really hard time getting the holes on the actual fan piece to mate.
    – The fasteners which A&I recommend have to be bought as does the adapter. I thought these were included in the fan package at first for some reason– maybe it was just me reading carelessly, just a reminder in case you read it fast like I did.

  10. Did you wait overnight after installing the adapter with silicone, before coating with dicor? Then wait another night before installing fan?

    I’d love to get it done in a day, but not sure if the silicone and dicor need time to fully cure first.

    Thanks for the great writeup!

  11. Thanks so much for this site Antoine and and Isabelle, you’ve inspired me to buy my own Ford Transit last week and I’m learning so much from your generous guidance! You’re truly my heroes!!

    This might be a stupid question, but could you tell us a bit more about your design decisions regarding the position and orientation of the vent fan? Why did you guys opt to place the fan in the front of the van facing forwards? And is your fan usually pushing air out or pulling in?

    Do you ever have the fan open while you’re driving and if so, wouldn’t this be less aerodynamic? Also, would putting the fan in the back give better airflow through the whole van– or was it more of a priority to vent kitchen gasses?

    • We installed it in the front mostly because we’re cooking in the van during winter (doors and windows closed); we wanted the van near the stove/oven. If you don’t plan on cooking a lot during winter, you can install it in the back so it maximize air flow when you open the front windows.
      You want air to exit the fan (push out), so make sure you have an air intake too.
      When it’s hot we drive with the cover of the fan opens; yes it’s less aerodynamic. So is opening windows. You can use A/C instead if you prefer.

      Good luck!

  12. Thank you so much for your build journal! I went to start the fan build and realized that I only bought the exterior Hein’s Ford Transit RV roof vent adapter. I believe I’m missing the interior part. Are there in fact two parts? I’ve searched on ebay and can’t seem to find the interior adapter. Any thoughts? Thanks again for all the work you’ve put in to this build!

  13. What are your thoughts on the framing strips that Hein offers along with the flange adaptor?
    Do you think these are necessary?

    • We didn’t use the framing strips, so they’re not “necessary”. But depending on your design, they might help to support your paneling (or else) around the fan cutout. The framing strips were not available when we built our van.


  14. Bonjour Antoine,

    Je t’avais contacté par courriel en septembre dernier afin de savoir si vous étiez satisfait avec votre moteur 3.7L. J’ai finalement trouvé et acheté un Transit 2016 highroof 148 non-allongé usagé avec un 3.7L également. J’ai commencé la conversion mais le gros du travail s’effectuera au printemps lorsque la température sera un peu plus clémente au Québec.

    Je planifie mon matériel pour l’installation d’un Maxxair 7500K. Je voulais savoir combien de tube Dicor avez-vous utilisé ? Est-ce qu’un seul suffit pour bien sceller le tout ?

    Merci beaucoup !


    • Salut Philippe,
      en effet y’a l’air à faire froid dans l’est cette année!

      Félicitation pour l’achat! Beaucoup de plaisir en perspective 🙂

      Si je me souviens bien, un seul tube est sufisant.

      Bonne continuation,

  15. hey bonjour les amie je suis Daniel Gatineau canada jai commande une transit 10 mois passer avec diesel je l’adore jai presque fini l’interieur,jai vraiment hate de finir loll,hey jai adorer votre maxxfan ca me donner une idee de m’en procurer une je vais l’installer a la meme place que vous.Dan

    • Salut Daniel,
      c’est tellement un bon feeling quand on termine, lâche pas!!

      La maxxfan est parfaite. Beaucoup de gens l’installe derrière aussi. Nous on l’a mis à l’avant parce qu’on cuisine dans la van en avant. Mais dans les 2 cas y’a pas de soucis!

      Bonne continuation!

    • – Not sure if the Silicone is compatible with the fan plastic?
      – Silicone is a mess to work with! (you will need a lot of it, it will be a PITA to remove if you ever need to)
      – Is that Silicone I that you have? If so, that’s a NO-GO!! Silicone I will promote rust on metal (always use Silicone II with metal)
      – Dicor is “self-leveling”; it will make better finish
      – Dicor might be better in the long run

      This is what comes to my mind!

  16. Nous allons recevoir notre Ford Transit tout neuf (merci pour les conseils pour la configuration de la van à l’achat) dans environ 3 semaines et votre site nous sera d’une grande aide pour la conversion de notre van. L’installation de la fan (Maxxair 6200K) sera évidement le premier projet. Je me demandais si vous étiez satisfait de l’endroit où vous avez installé votre fan. Dans mes recherches, j’ai vu que beaucoup de personnes l’installe à l’arrière pour créer une draft de l’avant vers l’arrière. Notre layout va ressembler au vôtre avec le lit en arrière et un espace cargo donc l’espace cuisine vers l’avant. De notre côté, notre projet est de se rendre en Amérique du Sud durant l’hiver. Nous n’avons pas l’intention de vivre des hivers à -30 dans notre van à court terme. Donc, nous vivrons beaucoup plus dans la chaleur. J’aimerais avoir ton avis sur l’emplacement de la fan.

    • Pour la chaleur, je crois que la fan est mieux positionnée derrière pour la raison que vous avez mentionné.
      En ce qui nous concerne, nous sommes satisfait de l’avoir installé à l’avant puisque nous devrons cuisiner l’hiver (les portes fermées); la Maxxfan est une excellente fan de cuisine! Nous sommes sur le point d’ajouter des trappes d’aération au plancher à l’arrière de la van pour optimiser la circulation d’air.

      Vous devez être très excité à l’idée de recevoir la van bientôt?! a+!

  17. vent looks great, having mine done in a few weeks.
    We have no windows in back, hoping this will give us some outside cool mountain air at night
    you mention 4 plastic covers from d pillars for vent holes, where are these?

    • Greg,

      they are under the van, near the very end of the van. These pictures show the location with/without the covers in place:
      Vent without covers
      with covers

      The air will enter the cargo area near the floor at the rear of the van.

    • For now, we just remove the 4 plastic covers from the d-pillars under the van; that create a minimum air flow. We will have to add more intake eventually.

  18. First off, thank you for such a simple, clean but detailed website. It’s been very helpful for us as we build our Transit van! We ordered our van and materials which were also helpful with your links. Installed the van today and it went mostly smoothly. Except for the lap sealant container exploding and our vintage 1980s jigsaw going dead on the first cut.

    Question: I notice that there is not much of a seal where the fan sits into the flang. You can see a little bit of black rubber and there is a slight gap there. We are thinking of siliconing that gap. We can always cut the silicone if we ever need to remove the fan. Did you guys noice the same thing or seal that gap?


    • Glad we could help!! 🙂

      I really don’t think this gap needs to be sealed. The manual does not state to seal it, so we did not seal it and have not heard of anyone who did. No leak so far!

      But how can a sealant container explode?! 🙂

    • Thanks! The fan performs well so far! We’re glad we went with the Maxxfan; we drive with the fan opened when it’s warm & we leave it open when it rains, awesome!

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