On the road a Sprinter Van does an ok job to keep the interior cool with the factory AC in the front cabin. It won’t freeze the whole van but in my experience a well tuned front AC is good enough to make a roadtrip in hot climates enjoyable. Expert Tip: have a small box fan blowing cool air from the front to the back – your passengers in the back will be much happier.
Without the engine running, however you’ll have to find different solutions to keep your cool. This post describes one of those solutions: an AC unit in the back of the Van that runs on AC that you can use while camping with access to shore power.
There are a ton of options available. Even AC units that also run on 12V DC which would allow you to cool the back of your van while you’re driving or if you don’t have access to shore power while stationary. I’ve looked into that as well but they require more work to install due to the more complex system and they are more expensive. I’ve wanted to have a unit on the roof of the van but people also installed window units. They are much cheaper but the final result looked crappy in my opinion.
AC units come in different sizes and “cooling power” (measured in BTU). The opinion on the boards is that you should at least pick a unit with 13,000 BTU for a van of the size of a Sprinter. Another thing you should consider is the height of the unit. Since it will be installed on your roof you’ll want the lowest unit available to minimize the air drag that will ultimately impact your gas mileage while driving.
My final choice was a Coleman Mach 8 unit with 13,500 BTU, which is one of the lightest and smallest units available: it just weighs 90 lbs and is just 8.25 inches high. You can see the final result in the picture above.
Picking the location of the AC unit on the roof
Installation of the AC requires to cut a hole in your Van, so spend some time to think about where you want the unit on the roof. Criteria for the installation spot are where you want the cold air in your van and what else you plan (or already have) on your roof. Since the AC was the first thing I put on the roof of my Sprinter I could play around with multiple layouts but the final decision was to put the opening for the roof pretty close to the middle of the rear section. The main reason for this was that with this layout the AC vents on the inside of the Van would distribute cold air evenly in the rear cabin. The final position was then chosen by the measurements of the solar panels that would go behind the AC once it was installed without any rooftop space “wasted”.
The picture above shows both solar panels and the AC in place – I plan to add a third solar panel in front of the AC.
Cutting the opening in the roof
The usual warning: Measure twice, cut once. You’ll need a 14″ x 14″ opening in the roof to install the AC unit. I measured from the inside of the van as it was easier to figure out the exact position in relation to the structural beams in the roof.
The procedure for cutting is the same as with the windows: use painters tape to protect the rest of the sheet metal, drill holes and start cutting with your Jigsaw and a good blade for sheet metal.
Installing the rooftop AC unit
The installation of the Coleman Mach 8 is pretty easy. The whole unit is actually just two parts: The heavy AC unit which sits on the roof (You better have some helping hands wrestling the 90 lbs. on the ladder up the roof) and the ceiling assembly with the air vents and controls for the AC.
The rooftop init is held in place with a square bracket which you need to bolt from the inside of your van. You’ll need to build some kind of support from the inside between the sheet metal and the bracket as the whole setup requires about 1.5″ distance between the two. I’ve used some Red Oak Plywood that I’ve painted with Polyurethane to protect it from soaking up humidity. Others welded metal structures for that. Just look at below picture to get an idea how the assembled thing looks like.
The plywood goes in between both structural pillars on the roof to add some additional support to the roof. You still have 90 additional pounds on the roof and you don’t want to end up with a dent in your roof due to the weight of the AC unit.
What’s left is to install the power line and the ceiling assembly with the air vents and controls and you’re good to go. Once I’m done with the paneling on the inside of my Van, I’ll post a picture of the final result.
Do you really need a real AC unit? Yes and No 🙂 It’s definitely nice to have one when you camp in really hot weather where it doesn’t cool down much at night (the wife will be happy!) but you don’t really need it most of the time. We recently went on a 5,000 mile trip and used the rear AC exactly for one night in a Texas State Park to cool down the van for an hour or so before going to bed. The rest of the trip we spend in cooler weather up north so the fan that we also have on the roof was enough to keep the temperature down inside. But I’m sure on one of the next trips (perhaps Florida?) we’ll be happy to have the Coleman AC unit with us.
- Rooftop A/C unit. You can find a good selection of units on eBay, Amazon or specialized online stores like AdventureRV.net (where I got mine).
- some leftover plywood for the frame
- Jigsaw with a metal cutting blade
- Drill with drill bit
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