Knowledge guide

How to Install a Fan in a Cargo Trailer

How to Install a Fan in a Cargo Trailer

Keeping cool while out on the camping adventure is a must! One of the simplest and most common ways to get some airflow is to install a roof-mounted 12v fan.

In this guide, I walk through the basics of how to get your fan installed. Be sure to watch our video below to learn more about our install.

Choosing a Roof Fan

There are several RV fans on the market. However, the two leading fans right now are the Fantastic Fan and the Maxxair MaxxFan.

There is an excellent write-up on the comparison between these two fans over at Parked in Paradise.

Let’s discuss our reasons for choosing the Maxxair MaxxFan.


Open While It’s Raining

The biggest draw for the Maxxair MaxxFan is obvious. The design makes it possible the leave it open while it’s raining.

This doesn’t seem like that big a deal, but consider whether you are confident that you will remember to close the dang fan every single time you leave, or there is a chance of rain. I had a camper growing up, and we were constantly in trouble for leaving the fan open.

This was really the most significant reason we chose the Maxxfan.

Maxxair claims you can leave it open while driving too. I’m not sure I am brave enough to test that, though.

Simple, Quiet, Easy to Install

There are a ton of videos online of people installing and testing the MaxxFan. The fans are well tested and incredibly reliable.

At medium to low speeds, the fans are quiet enough that you can easily ignore them.

Installing the fan was a breeze as well. You essentially cut the hole and stick it in there!

Which Maxxair MaxxFan Should I Choose?

What is the Difference Between Each Model?

At first glance, the number of Maxxair MaxxFans is incredibly confusing so let’s make it simple as possible.

There are essentially three models:

  1. 4-speed with a manual turn-knob to open and close (5301K & 6401K)
  2. 10-speed with a manual turn-knob but some additional features (5100K & 6200K)
  3. 10-speed with a remote and those additional features (7000K & 7500K)

All three of these models come in two colors: White and Smoke. White has a solid plastic top that isn’t seethrough. Smoke looks black but is actually seethrough.

That makes a total of six different units. Here’s a good chart from Parked in Paradise:

2021-07-14 04.38.31.jpg

Which Maxxair MaxxFan is the Best?

There is a lot of debate about the best model of fan. They all have their pros and cons.

The low-end models (5301K & 6401K) are simple: Manual open and close and only four speeds.

The mid-models (5100K & 6200K) have additional features such as a thermostat that automatically turns the fan on and off. These models also can operate in reverse, meaning air can either be pushed out or pulled in depending on what kind of airflow you want. These also have 10-speed settings instead of 4.

The high-end models (7000K & 7500K) have all of the above features PLUS a battery-powered remote that controls all the operations.

Why We Chose the 6401K

So why did we choose the lowest-end model? Simple: cost and simplicity.

At the time of writing, there’s a $100 difference in the price of the low-end and high-end models. I want to save money where I can, and since we are putting a mini-split AC unit in our trailer, a fan is a bit of an afterthought.

Secondly, I am a firm believer in keeping technology simple when possible. The fewer electronics a device has, the less likely it is to malfunction and the less expensive and difficult it is to repair.

Caitlin and I watched a lot of videos on these fans before making our decision, and the above rule appears to be true. The circuit boards on the high-end units have a history of failing occasionally.

In addition, we observed feedback from other YouTubers that felt that 10-speeds seem nice on paper but, in reality, only used 1 or 2 speeds in practice.

Lastly, the electronic units sound like loud screeching animals when they go up and down electronically. Ok, maybe that’s an exaggeration but I needed a third point.

So we chose the simple 6401K. You should too!

How to Install a Maxxair MaxxFan

Tools and Supplies

  1. Maxxair MaxxFan
  2. Jigsaw
  3. Impact drill
  4. Safety goggles
  5. Hearing protection
  6. Self-tapping screws (hex-head)
  7. Lap Sealant
  8. Caulk Gun

The van life community has a ton of experience with this fan. There are so many videos on YouTube on how to install it, we didn’t bother doing another one ourselves.

Below is one of the videos we referenced when installing our fan.

Instead of walking you through every step in this write-up, here are a series of tips we think will help you with your install.

Think About Placement

When placing the fan, it’s easy to just stick the fan in the middle and be done with it.

Since installing the fan is one of the first jobs to do with your DIY cargo trailer conversion, it’s easy to lose sight of the importance of the placement decision.

Here are a few things to consider:

  1. Will there be solar panels on the roof? If so, you better at least have an idea about how many you want to put up there and how they will be positioned around the fan. Remember, solar panels can be really affected by even the slightest shadow.
  2. What kind of airflow are you seeking? Will there be windows to pull from in all directions? If you have all your windows on one end and the fan in the middle, the opposite end of the trailer may be left with a less desired airflow.
  3. Do you have a bed that lifts to the ceiling? In our design, our bed will be against the ceiling when not in use. We almost put the fan right above the bed too. That would have made the fan useless when the bed is in the raised position.

Think a lot about your overall design before you cut a big hole in your roof!

Start Your Hole from the Inside

It’s much easier to measure equidistant from your walls from the inside of the trailer than on the roof!

When getting ready to cut, measure and center between the beams from the inside of the trailer. You can use the plastic trim as a guide for your holes.

Then, when you have it adequately marked off, use a drill to put a small hole at each corner. That way, when you do crawl up on the roof, you simply have to hold your trim against the holes to quickly draw your square for cutting.

Remember, small holes can be patched! But a colossal square cutout may not!

Keep Your Weight on the Beams

When crawling on the roof, be sure to keep your weight on the beams, which are easy to locate by feel alone with your hands and knees.

My manual says that any point on the roof has a 250 lb weight capacity. I am sure that does not mean right over the top of the thin aluminum between the beams.

Don’t fall through the roof!

Have Some Help!

You will inevitably forget something once you get on the roof.

Have a partner ready to toss you the bag of screws you forgot.

(This actually happened).

Use Better Screws

The screws that come with the fan are trash.

Use your own self-tapping screws and make sure you have some long enough to make it through the roof into your frame. We used 1.5” screws.

I believe that Phillips head screws are terrible, and I always strip them. I recommend getting some with hex heads.

Build a Frame on the Inside

This one seems obvious, but build a simple square frame on your ceiling interior to screw into from the outside.

The roof is thin, and you don’t want the fan blowing away because it isn’t securely attached.

I had Caitlin hold the frame in place while I screwed into it from the outside.

That’s it! I hope this guide was helpful. As always, drop a question below or shoot us an email, and if we can help, we will!

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